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Home My WebLink AboutAPA91SUSITNA HYDROELECTRIC PROJECT SUSITNA RIVER ICE STUDY 1982-1983 -'c;'i' f\Vt1 t=IAM CON.ULTANTa. INC. •••• II --lie ... , .. _ -.~ TASK 4: ENVIRONMENTAL PRELIMINARY DRAFT AUGUST 1183 Prepared for: s6/gg1 ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT TASK 4 -ENVIRONMENTAL SUSITNA RIVER ICE STUDY Prepared by: G. Carl Schoch R&M Consultants, Inc. 5024 Cordova Street Anchorage, Alaska 99503 Telephone (907) 561-1733 1982 -1983 August 1983 Prepared for: Harza/Ebasco Joint Venture 8740 Hartzell Road Anchorage, Alaska 99507 Telephone (907) 349-8581 s6/gg2 ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT SUSITNA RIVER ICE STUDY 1982-1983 TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF PHOTOGRAPHS ACKNOWLEDGMENTS 1. 2. 3. 4. INTRODUCTION 1.1 Background 1. 2 Scope of Work for 1982-1983 SUMMARY METEOROLOGY SUSITNA RIVER FREEZE-UP PROCESSES 4.1 Definitions of Ice Terminology and Comments on Susitna River Ice 4.2 4.3 Frazil Ice Ice Cover Development 4.3.1 Cook Inlet to Talkeetna 4.3.2 Talkeetna to Gold Creek 4.3.3 Gold Creek to Devil Canyon 4.3.4 Devil Canyon (to Devil Creek) - i - Page iii v vii xii 1 1 2 7 10 26 26 29 34 34 40 49 52 s6/gg3 TABLE OF CONTENTS (continued) 4.3.5 Devil Canyon to Watana 4.3.6 Ice Cover at the Peak of Development 5. SUSITNA RIVER BREAKUP PROCESSES 5.1 Ice Cover Deterioration 5.2 Ice Jams 6. SEDIMENT TRANSPORT 7. ENVIRONMENTAL EFFECTS 7.1 Susitna River Below the Chulitna River Confluence 7. 2 Susitna River Above the Chulitna River Confluence 8. REFERENCES APPENDIX A Monthly Meteorological Summaries from Weather Stations at Denali, Watana, Devil Canyon, Sherman, and Talkeetna APPENDIX B Susitna River maps (Aerial Photo Mosaics) from Sunshine to Devil Canyon -ii - Page 59 60 88 88 91 128 132 132 134 138 141 184 [ L l ~ l L L [ r L r L. s6/gg4 Table Number LIST OF TABLES Title 1.1 River Mile Locations of Significant Features on the Susitna River. 3.1 Meteorological Data Summary from Selected 3.2 3.3 3.4 4.1 Weather Stations Along the Upper Susitna River, September 1982 -May 1983. Number of Freezing Degree Days (°C), September 1982 -May 1983 Number of Freezing Degree Days (°C), September 1981 -May 1982 Number of Freezing Degree Days (°C), September 1980 -May 1981 Susitna River Surface Water Temperature Profile, September 1982 -October 1982 4.2 Susitna River at Talkeetna, Freeze-up Observations on the Mainstem 4.3 Susitna River at Gold Creek, Freeze-up Observations on the Mainstem, October 1982 4.4 Susitna River at Gold Creek, Freeze-up Observations on the Mainstem, November 1982 -iii - Page 5 13 16 19 21 62 63 64 65 s6/gg5 Table Number 4.5 4.6 4.7 4.8 4.9 5.1 5.2 5.3 5.4 LIST OF TABLES (continued) Title Susitna River at Gold Creek, Freeze-up Observations on the Mainstem, December 1982 Susitna River at Gold Creek, Freeze-up Observations Observations on the Mainstem, January 1983 1983 Susitna River Ice Thickness Measurements River Stages at Freeze-up Measured from Top of Ice Along Banks at Selected Locations Major Annually Recurring Open Leads Between Sunshine RM 83 and Devil Canyon RM 151 Locations and Specifications on March 2, 1983 \Vater Stage and River Ice Thickness Measurements at Selected Mainstem Locations Susitna River at Susitna Station Breakup Observations on the Mainstem. Susitna River at the Deshka River Confluence Breakup Observations on the Mainstem. Susitna River at Gold Creek Breakup Observations on the Mainstem. -iv- Page 66 67 68 69 70 106 111 112 113 r, L [ l_ L_ [ l ~ [ L L L [- s6/gg6 Figure Number 1.1 LIST OF FIGURES Title Susitna Hydroelectric Project Location Map 3.1 Mean Monthly Air Temperatures, September 1982 -May 1983 and Historical Averages 3.2 Freezing Degree Days Monthly Totals, 3.3 September 1982 -May 1983 and Historical Averages Monthly Precipitation Data, October 1982 -May 1983 4.1 Ice Concentration at Talkeetna Relative to Mean Daily Air Temperatures at Denali and Talkeetna, and Daily Total Snowfall at Talkeetna. 4. 2 Ice Concentrations at Gold Creek Relative to Mean Daily Air Temperatures at Devil Canyon and Daily Total Snowfall at Gold Creek 4.3 Susitna River Ice Leading Edge Progression Rates (mile/day) Relative to the Thalweg Profile from River Mile 0 to 155 -v- Page 6 23 24 25 73 74 75 ' s6/gg7 Figure Number 4.4 4.5 5.1 LIST OF FIGURES (continued) Title Stage Fluctuations in Ground Water Well 9-1A Relative to Mainstem Discharge Time lapse Camera Location at Devil Canyon Water Surface Profiles Along 1,600 Feet of River Bank Adjacent to Slough 21 Before and During an Ice Jam -vi- Page 76 77 114 [ [ [ r , L~ s6/gg8 Photo Number 4.1 4.2 4.3 4.4 4.5 4.6 LIST OF PHOTOGRAPHS Description Ice plume near Slouqh 9 View of the mainstem, adjacent to the Town of Talkeetna on October 12, 1982. View of the mainstem, adjacent to the Town of Talkeetna on October 30, 1982. View of Mainstem, adjacent to the Town of Talkeetna on November 4, 1982. Slush ice accumulating by juxiposition on October 29, 1982 at Sunshine. Shore ice constriction near Slough 9 on October 26, 1982. 4. 7 Shore ice constriction in Devil Canyon on October 21, 1982. Page 78 78 79 79 80 80 81 4.8 Ice bridge in Devil Canyon on October 21, 1982. 81 4.9 View of the Chulitna confluence with the Susitna mainstem, looking upsteam on October 29, 1982. 82 4.10 Susitna River confluence with the Chulitna east channel on November 2, 1982. 82 -vii - s6/gg9 Photo Number 4.11 4.12 LIST OF PHOTOGRAPHS (continued) Description Susitna River confluence with the Chulitna, view looking downstream on November 9, 1982. The Susitna River at river mile 99.6 looking upstream on November 2, 1982. 4.13 Susitna River at river mile 106 on November 17, 4.14 4.15 4.16 4.17 4.18 4 .. 19 1982. Open leads on February 2, 1983 at river mile 103.5. Susitna River at Gold Creek on October 16, 1982. Susitna River at Gold Creek on January 13, 1983. Sample of ice taken during breakup at river mile 142. Extensive shore ice development near the confluence of Devil Creek. View looking upstream at river mile 104 on February 2, 1983. -viii- Page 83 83 84 84 85 85 86 86 87 f ' r L l ~ [ . r . I L. s6/gg10 Photo Number 4.20 5.1 5.2 LIST OF PHOTOGRAPHS (continued) Oeser if,. i;ion Time lapse camera mounted on the south rim of Devil Canyon Ice cover in Devil Canyon at river mile 151 on October 20, 1982. View looking upstream at river mile 107 on April 7, 1983. 5.3 View looking downstream on the upper Susitna River near the confluence of Fog Creek. 5.4 Moose entrapped in the slush ice during 5.5 freeze-up. The confluence of Deadhorse Creek (at Curry) on April 28, 1983. 5.6 Photo showing a large ice jam at Curry on May 6, 1983. 5.7 Ice jam adjacent to Slough 21 on May 4. 1983. 5.8 Ice blocks shoved over the river bank at Slough 21 on May 5, 1983. 5.9 Gravel and cobble size particles being rafted. -ix- Page 87 115 115 116 116 117 117 118 118 119 s6/gg11 Photo Number 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 LIST OF PHOTOGRAPHS (continued) Description Key of an ice jam adjacent to Slough 11 releasing. An aerial view of the ice jam near Sherman at river mile 131.5 on May 6, 1983. Ice sheet that wedged near Shet·man. Ice sheets holding back the ice jam at Sherman. Ice jam at Sherman. Redirected flow into a side channel on May 8, 1983. Ice jam near the Susitna confluence at river mile 98. Ice blocks on the gravel bar below Deadhorse Creek. Particles shoved up onto an ice sheet at Curry. Massive blocks of consolidated slush ice with clear ice lenses. Stratigraphy within an ice cover fragment. -x- Page 119 120 120 121 121 122 122 123 123 124 124 [ [ L L L [ L [ [ L L L s6/gg12 Photo Number 5.21 5.22 LIST OF PHOTOGRAPHS (continued) Description Large ice fragment stranded on a bank. Rippling on the underside of an ice cover. 5.23 Ice debris piled onto the river bank at river mile 101.5. 5.24 View of the shear wall near river mile 110. 5.25 Ice scoured river banks. 5.26 Gold Creek Bridge, May 7, 1976. Page 125 125 126 126 127 127 slG/aal ACKNOWLEDGMEi-.11 5 This study was conducted under contract to Acres American, Inc. until February 1983, and then Harza/Ebasco Susitna Joint Venture. Funding was provided by the Alaska Power Authority in conjunction with studies pertajning to the continuing environmental impact assessment for the proposed Susitna Hydroelectric Project. Many individuals participated in the field data collection efforts during freeze-up and breakup. The logistics involved in documenting over 200 miles of ice cover development was difficult and therefore many ice measurements and daily observations were dependent on local residents. The conscientous efforts, often during severe weather conditions, by Butch and Barb Hawley at Susitna Station, Leon Dick at the Deshka River Confluence, Walt Rice at Talkeetna and the Larson's at Gold Creek are sincerely appreciated. The services provided by Air Logistics, and particularly the judgement and skill of the pilots, was invaluable in obtaining ice thicknesses, water velocities and observations of releasing ice jams. The cooperation of the Watana Camp Staff (Knik/ADC) and Granville Couey (Frank Moolin & Assoc.) in arranging the logistic support was extremely helpful. Other agencies who contributed time and information to this study include the Alaska Department of Fish <.. Game, the National Weather Service, NWS -River Forecast Center, Acres American, Inc., and the Alaska Railroad. The Arctic Environmental Information and Data (AEIDC) Center provided the needed personnel and equipment to assist in breakup documentation. Special thanks goes to Joe LaBelle for coordinating this joint effort. -xii- s16/aa2 I am especially grateful to Jill Fredston (AEIDC) for assistance in editing this report and contributing a great deal of time and energy in order to accomplish this task on time. This ice study was developed with the assistance and guidelines of Steve Bredthauer, senior hydrologist at R&M Consultants, Inc. The R&M Hy- drology staff provided assistance with field measurements and much useful information from occasional aerial observations. In addition the extraordi- nary patience of the typing staff and their efforts towards a timely· com- pletion is sincerely appreciated. -Xiii- ... i f f ( r· f'' 1 L ~- r [ ~ L ,----": L [ [' r - L r: [ [ [ l L L r L_ s16/w1 1.0 INTRODUCTION The study of ice on the Susitna River has been ongoing since the winter of 1980-1981. The documentation has been restricted to oblique aerial photography and intermittent observations by field crews. Initially, the intent was to target locations of specific ice processes such C!S frazil ice generation, shore ice constrictions, ice bridges, and ice jams. Much qualitative information was gathered and documented in the Ice Observa- tions Reports (R&M 1981b, 1982d). Renewed emphasis by environmental concerns on potential modifications to the river ice regim~:: by hydroelectric power development resulted in a more refined ice program for 1982-1983 directed towards specific problems which may be unique to the Susitna River. Staging, ice cover development in sloughs, ice jams and their relationship to sloughs, and sediment transport are among the topics discussed in this report. It is beyond the scops of the current study to mathematically analyze the specific mechanics of river ice processes, in- stead, the objective is to describe the phenomena based on field observa- tions .and measurements. 1 . 1 Background Beginning in the winter of 1980-1981, R&M Consultants was involved in surveying over 100 river cross sections between Talkeetna and the proposed damsite at Watana (R&M 1981a, 1982c). Ice thickness data were collected in conjunction with these surveys and used to compile a profile of the Susitna River ice cover downstream of Watana. Additional historical information on ice thicknesses is available from the U.S. Geological Survey (USGS). This agency maintains several ~treamgaging sites on the Susitna River and most are visited during the winter to obtain under-ice discharges. Upper Susitna data re- cords begin in 1950 for Gold Creek and 1962 for the Cantwell site. Bilello of the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) conducted a comprehensive study entitled, "A -1- s16/w2 Winter Environmental Data Survey of the Drainage Basin of the Upper Susitna River, Alaska'' (1980). This report summarizes monthly ice thickness measurements from 1961 to 1967 at Talkeetna and from 1967 to 1970 near Trapper's Creek. Information concerning other aspects of the ice regime on the Susitna is scarce. The best potential source for a variety of qualitative historical information concerning ice jams and floods are area re- sidents, especially those employed by the Alaska Railroad. Many interviews were conducted and the resulting information was docu- mented in the 1981 ice report (R&M 1981b). This first ice report consisted mostly of narrative chronological descriptions based on aerial observations at various sites. The report also contains most of the historical information available from the U.S. Geological Survey, the National Weather Service -River Forecast Center, and the U.S. Army, Corp of Engineers. The ice study of 1981-1982 followed the same general guidelines. Aerial reconnaissance was conducted weekly through January and the freeze-up sequence was described in the final report (R&M 1982d). Ice thickness measurements were obtained at many of the locations surveyed in 1981 in order to assess yearly variability. Breakup was periodically observed from April 12 to May 15, and documentation was limited to information gathered on aerial overflights. 1.2 Scope of Work for 1982-1983 The Susitna River ice studies evolved considerably during the past year. Emphasis was placed on documenting site specific, ice cover induced problems identified during previous observations. These included ice jamming and flooding at the Susitna confluence with the east channel of the Chulitna River, staging effects through spawning areas, and ice jamming near the proposeci upstream cofferdam at -2- r' L L f . [ [ l L L s16/w3 Watana. Reaches where ice jams recur annually were investigated for morphologic changes and identification of critical factors governing ice jam formation. Collection of additional quantitative data was also required for proposed modelling efforts. These data included ve- loc::ities, maximum stages at various sites, ice thicknesses, ice dis- charges, ~+es of ice cover advance, water temperatures, and loca- tions of signit. ~"nt open leads. The number of observations was increased in proportion to the frequency of specific ice events and during breakup, field crews documented daily changes in the ice cover. The specific data collected during the 1982-1983 season in- eluded: 1 . Locations of ice bridges 2. Rate of upstream progression of the ice cover 3. Ice discharge estimates 4. Ice cover at tributaries 5. Ice cover at aquatic habitat areas 6. Water temperature 7. Locations and size of open leads 8. Aerial photography, oblique and vertical 9. Meteorological data at specific sites 10. Ice cover processes in Devil Canyon 11. Maximum water levels 12. Ice thicknesses 13. Velocities and discharges 14. Profiles and cross sections 15. Time-lapse photography 16. Locations and effects of ice jams 17. Water table fluctuations Meteorological data from five weather stations near the river channel are summarized in Section 3. In addition, figures are provided that illustrate the variability in air temperatures, freezing degree-days and precipitation from the upper Susitna at Denali to Yalkeetna. -3- s16/w4 Section 4 considers the processes associated with ice cover develop- ment and how they relate to the 1982 Susitna River freeze-up. Breakup is described in Section 5, beginning with the initial pro- cesses of ice deterioration followed by the cause and effects of ice jams. The subtle processes of sediment transport during freeze-up are described in Section 6, along with the more dramatic nature of ice scouring and erosion during breakup. Section 7 discusses the environmental effects induced by ice cover development. Topics. in this section include: 1. Channel morphology changes 2. Aquatic habitat modifications 3. Relationship between sloughs and ice jams 4. Damage to vegetation 5. Ice regime in side channels and sloughs 6. Flooding of islands Photographs illustrating specific ice processes and events, have been included in order to assist those who are unfamiliar with river ice in gaining an understanding of the characteristic~ and effects of the Susitna River ice regime. Many of the discussions in this report rely on a familiarity with certain place names and river mile locations. Table 1.1 lists those which are environmentally significant and often referred to in the test. Figure 1.1 shows the Susitna Hydroelectric Project location relative to southcentral Alaska. River mile locations have been an- notated on detailed river maps included in Appendix B. Left bank and right bank in this report refer to the respective shorelines when viewed looking downstream. -4- ~~ i r l- l' I. r· l. I 1 . r· L L r L [ r L [ [ l l' L ! ~ l_ l_ TABLE 1.1 RIVER MILE LOCATIONS OF SIGNIFICANT FEATURES ON THE SUSITNA RIVER Place Devil Canyon Portage Creek Slough 22 Slough 21 Indian River Gold Creek Slough 11 Sherman Slough 9 Slough 8 Slough 7 Curry Lane Creek Chase Whiskers Creek Chulitna/Susitna Confluence Talkeetna Birch Creek Slough Sunshine/Parks Highway Bridge Rabideux Creek Montana Creek Goose Creek Slough Kashwitna Creek Willow Creek Oesh ka River Yentna River Susitna Station Alexander Slough Alexander River Mile * 150.0 149.0 144.5 142.0 138.5 136.5 136.4 131.0 129.0 127.0 123.0 121.0 114.0 108.0 101.0 98.5 97.0 93.0 84.0 83.0 77.0 72.0 61.0 49.0 40.5 28.0 25.5 19.0 10.0 * Photo mosaic maps indicating river miles are included in Appendix B. Locations indicate the most upstream and or entrance. s6/ll - 5 - t.OC..\TION MAP \1 ;»ROPOSE!l OAM Sii;:.S ~ .~ ~.11R8ANKS 'u ~~-'" ·-·~"· ·~ .... {· ' SUSITNA HYDROELECTRIC PROJECT LOCATION MAP Flour• 1.1 -6- JJWlUl·JEIIMCaJ SUSITNA JOINT VENTURE RS.M CONSULTANTS, INC. •Nti•N•••• a•OLOa••'~'• ..... ~,.. ...,•v••ca•• r- i l - r I r I f - l < • L r L L [ { L ! L~ r l ! ! L. s16/v1 2.0 SUMMARY Frazil ice generally first appears on the Susitna River between Denali and Vee Canyon. This reach of river is commonly subjected to freezing air temperatures by mid-September. By the end of October 1983, the entire river had cooled to 0°C and frazil slush had accumulated into an ice cover that started near Cook Inlet and extended upstream to Talkeetna. The development of an ice cover on the lower river below Talkeetna required only about 14 days. This rapid ice cover progression was due primarily to the gentle gradient, low flow velocities and broad river channel common to this section. Very little staging was necessary during the ice cover advance, generally 1-2 feet upstream to approximately river mile (RM) 67 and then steadily more as the channel gradient became steeper. At Talkeetna the staging amounted to over 4 feet near the entrance to a side channel. On November 5, 1983 an ice jam occurred at the confluence of the Chulitna River east channel and the Susitna mainstem. This initiated the ice cover progression on the Susitna upstream to Gold Creek. Staging along this reach was generally more extreme with water levels commonly increasing more than 4 feet. The leading edge reached Gold Creek by January 14, 1983 after having slowed to a progression rate of only 0.05 miles/day. This was due to a reduction in the ice discharge caused by the development of an ice cover in the upper river which effectively sealed off the air/water interface preventing frazil generation. The reach from Gold Creek to Devil Canyon took considerably longer to freeze and the processes involved were also different from those in the reaches further downstream. This area experienced extensive shore ice development and ice dams." A time lapse camera was mounted on the south rim of Devil Canyon in order to document the formation of massive ice shelves that develop near the proposed damsite. The ice cover in this turbulent, high velocity reach, often the first to form on the entire Susitna River, was very -7- s16/v2 unstable and was constantly either disintegrating or accumulating. The 8 mm movie camera provided footage that revealed valuable information concerning how an ice cover forms over rapids. The upper river from Devil Canyon to Denali was not monitored closely during freeze-up or breakup but routine flights to Watana Camp provided much interesting qualitative information on the processes affecting this reach. Essentially, this reach develops wide shore ice by building successive layers of frazil and snow slush. The channel finally becomes so narrow that slush is entrapped and eventually freezes into a continuous ice cover. After an inital ice cover forms, continually decreasing water levels lower the floating ice until the majority of the cover has settled on the bottom, often conforming to the channel configuration. Open leads begin developing over turbulent water. Some may gradually close again through accumulations of fine slush ice against the downstream edge of the lead. Many open leads persist all winter. Groundwater seeping into the mainstem, side channels and sloughs usually erodes away the existing ice cover. These areas can remain ice free for most of the winter. Breakup is generally initiated by increasing incident sole r radiation, warm air temperatures, and subsequent rising water levels. The first effects are seen during April when open leads begin to enlarge and the ice cover surrounding these leads is gradually undercut by higher flows. Ice fragments collapse into the leads and drift downstream to pile up against the solid ice cover. Eventually open leads may merge, creating a long, wide channf.l. The small jams commonly associated with the lead enlargement process, can accumulate sufficient mass to ground on the channel bottom. This caused the first jams to form at Lane Creek and at Slough 21. Essentially, open leads continue lengthening until the river is divided between reaches of open water and large masses of accumulated ice -8- r I [ L L r--L L L L I L- s16/v3 debris. The ice jams then release in succession starting with the jam furthest upstream which, in 1983, was at Slough 21. The debris drifts with the current until encountering the next jam. The volume of drifting ice can become so massive that most ice jams are immediately swept away, further increasing the total accumulated mass. In May of 1983 an extensive buildup of flowing ice debris was stopped near Chase by a combination of the only remaining solid ice cover, and a shallow reach of river nearly 3 miles long. The ice cover disintegrated on impact but stalled the flow long enough for the ice to pile up and ground fast. This jam held for two days and the ice debris then flowed unobstructed to Cook Inlet. Although by May 10, 1983 the entire river was essentially ice free, ice floes continued drifting downstream for several weeks as previously stranded floes were picked up by steadily increasing discharges, The lower Susitna River downstream of Talkeetna experienced an extremely mild breakup. Observers at the Deshka River confluence and at Susitna Station thoroughly documented breakup this year. Their descriptions and data indicated that the ice cover fragmented and flowed out between May 2 and May 4. Most of the ice cover simply deteriorated while remaining shore-fast and little jamming activity took place. The only significant ice jam below the Parks Highway Bridge occurred near the confluence with Montana Creek. This past river ice season was significantly moderated by mild temperatures and snowfall. Ice thicknesses did not reach proportions of previous years and little precipitation occurred during breakup. Much data was documented during freeze-up in 1982 and breakup in 1983 for computer modelling input but it must be recognized that they do not necessarily represent conditions in a normal year. -9- sG/hhl 3.0 METEOROLOGY Mathematical derivations of heat exchange coefficients will be required for computer simulations of river ice cover formation. Accurate and consistent measurements of .neteorological parameters are essential for developing representative values for the heat gain and heat loss components of the energy exchange equation. A detailed heat exchange analysis is beyond the scope of this report. This section is limited to brief comments on the processes of surface heat exchange, definitions of the mechanisms by which they occur and identification of the meteorological parameters that are currently being monitored in the vicinity of the Susitna Hydroelectric Project. Natural water bodies receive the most heat from solar shortwave radiation (Hs) and longwave atmospheric radiation (Ha) I and lose heat to the atmosphere by longwave back radiation (Hb), evaporation heat loss (He), and conduction heat loss (He). Not all of the incoming solar and long wave radiation is absorbed. A certain percentage is reflected at the water surface and these values are generally computed based on reflectivity coefficients which are ratios of reflected radiation to incident radiation. Reflected solar radiation (H ) is usually of greater magnitude than sr reflected at1~ospheric radiation (Har), but more variable due to cloud cover I latitude, and altitude. The net rate of heat transfer across a water surface is: The parameters representing the absorbed radiation, combined in the parentheses on the left, are independent of the water surface temperature. The terms in the right parentheses represent the temperature dependent parameters of heat loss, (Edinger, 1974). -10- I l I' I ' ~- [' ,- [ L [ ['' [' L [' [ [ L l [ L~ I [__ s6/hh2 Values for the individual heat exchange components can be derived from the following measured meteorological variables: solar radiation, air temperature, and dew point temperature. These parameters have been monitored at several locations throughout the upper Susitna Basin for the past 3 years by R&M Consultants. In addition, a 42 year record is available from the meteorological station at the Talkeetna Airport operated by the National Weather Service. These weather stations were selected for the data summaries included in this report because they are situated close to the river and most accurately represent the climatic regime directly influencing the water surface. They are located at Denali, Watana, Devil Canyon, Sherman, and Talkeetna. Additional information about each weather station, including exact location and sensor specifications, have been published previously and is therefore not included in this report. Those readers not familiar with this aspect of the project may wish to consult the Processed Climatic Data Reports, Volumes 1-8 ( R&M, h)82e) which includes a detailed description of the meteorological data collection program. Mean maximum, mean minimum and mean daily air temperatures for each station from September 1982 through May 1983 have been summarized in Table 3.1. Mean daily air temperatures are plotted in Figure 3.1. Tables 3.2, 3.3, and 3.4 list the number of freezing degree-days per month between September and May for the existing record at each station (Talkeetna 1980-1983 only), and are graphed in Figure 3.2. Only the Watana (R&M Consultants) and Talkeetna (NWS) stations have the capability to measure precipitation on a daily basis throughout the winter months. These data have been plotted in Figure 3.3. The meteorology within the upper Susitna Basin is highly variable at any given time between weather station sites. This is due, in part, to the movement of storm systA.ms, the topographic variance, and the change in latitude, but mostly to the 2,400 feet difference in elevation between Denali and Talkeetna. The graphs presented in this section illustrate not only the colder daily temperatures at Denali but also their longer duration. In -11- s6/hh3 October 1982, for instance, Denali had a total of approximately 370 freezing degree days (°C) while Talkeetna had only 170. This difference may be significant since the entire Susitna River downstream of Talkeetna developed an ice cover by November 1, 1982. Caution is therefore advised in using average values for the Susitna Basin since these may not be representative of any location along the river. There is also significant difference in precipitation and wind run between Watana and Talkeetna. Watana receives only a fraction of the precipitation measured at Talkeetna primarily because of orographic effects at Watana and the high concentration of storm systems from Chulitna Pass to Talkeetna. The Watana weather station is situated on a high plateau and is exposed to wind runs not common on the river. The data summarized in the tables and figures in this section are based on published and provisional monthly meteorological summaries from each respective weather station. These have been included in Appendix B. -12- L L [ [ [ L L r, [ [ L, I L ..... w l' s5/ee1 TABLE 3.1 METEOROLOGICAL DATA SUMMARY FROM SELECTED WEATHER STATIONS AI.ONG THE UPPER SUSITNA RIVER SEPTEMBER 1982 -MAY 1983 Air Temperatures -Mean ··---Mean ~lean Departure Departure Depth of Snow Maximum Minimum Munthly from Normal P rec i p i t.a t I on from Normal on Ground 'oc) --~ 'oc) (°C) (mm) l!!!!!!l (C!!l) SepLember 12ag Talkeetna 11.5 4. 1 7.8 0.0 190.0 76.1 o.o Sherman 11.4 2.8 .,. 1 0.0 232.2 o.o Devi I canyon 9.5 2.5 6.0 1.11 156.6 59.1 Watana 8.4 1.6 5.0 0.4 100.8 15.6 Denali* 3.6 -0.2 Basin Average 10.2 2.8 5.9 0.3 169.9 3'1. 7 0.0 o~ao~g r 12ag Talkeetna -0.6 -9.4 -5.0 -4.9 52.2 -11.8 40.3 Sher~aan* 1.0 -8.0 -5 •. , 0.0 Oevi I Canyon -2.6 -9.8 -6.2 -4.1 Watana -3.3 -11.9 -7.6 -3.8 4.2 -6.1 Denali -11.8 -6.0 Bas in Average -1.4 -9.8 -7.3 -3.8 28.2 -9.0 !':fQ~O!!!bO( 12ft2 Talkeetna -4.4 -12.6 -8.5 -0.4 42.8 -2.3 70.6 Sherman* -4.5 -11.4 -10.0 o.o Devi I Canyon -5.8 ·11.9 -8.9 -1.5 Watana -7. 1 -14.4 -10.7 -1.4 0.2 -2.4 Dena II* -15.7 -5.2 Basin Average -5.5 -12.6 -10.8 -1.7 21.5 -2.4 * Partial Record -Some valtms l'or mean daily temperatures, used to compute the mean monthly temperature, are based on linear regression analysus. See Jl.ppendix A. I ..... ~ r-- l ~)/f "? TABLE 3.1 (Cont.inued) Air Teml!erat.tJ.res Mean Mean Mean Departure Oepa rture Depth of Snow Maximum Minimum Mont.hly from Normal Precipitation from Normal on Ground (°Cl -· (°CI '°Cl '°Cl (mml (mml (em I December 12~g Ta I keetna -3.5 -10.8 _., .2 5.6 45.4 2.3 73. 1 Sherman -4.8 -12.7 -8.7 0.0 Devi I Canyon -5.1 -11.3 -8.2 IJ,4 Watana -6.9 -13.9 -10.11 II. 7 7.0 2.3 Dena I i* -9.6 -19.6 -15.4 ,,,8 Basin Average -6.0 -13.7 -10.0 3.9 26.2 2.3 ,!anuar:t: 1983 Talkeetna -6.2 -15.4 -10.8 2.3 11.6 -24.9 80.6 Sherman* -8.6 -17.11 -11.0 o.o Devi I Can;yon* -8.5 -15. ,, -11.4 -1.5 93.2 Watana -11.0 -11.4 -14. 1 -1.2 2.8 1.3 26.2 Dena I i* -12. 1 -22.0 -17.1 -1.2 20.9 Basin Average -9.3 -17.5 -12.9 -0.3 7.2 -11.8 55.2 februa r:t: 12!U Talkeetna -1.7 -13.3 -7.5 2.3 11.6 -27.0 80.6 Sherman* -9.1 -21.5 -8.0 0.0 107.9 Devil can:von -3.2 -11.9 -7.5 1.5 93.2 Watana -6.5 -13.6 -10,0 -2.5 0.0 -15.2 29.0 Danai i -8.9 -19.3 -14. 1 0.7 25.7 Basin Average -5.9 -15.9 -9.4 0.4 5.8 -21.1 6'1. 3 * Part.ial Record -Some valu~s l'or mean daily temperatures, used t.o compute the mean monthly temperature, are based on linear regression analysos. see Appendix A. • ' ' Partial Record -Some values for mean dally temperatures, used to compute t.he mean monthly temperature, are based on linear regression analyses. See Appendix A. ,- s5/hh1 [ ,- I . TABLE 3.2 NUMBER OF FREEZING DEGREE DAYS (°C) I ~ September 1982 -May 1983 ,~ Average I. Historical** ! Record Mean Monthly Normal Air Temperature Month I~ Accumulated Month (oC) Se,.,tember 1982 r~ Talkeetna 0 0 0 7.8 Sherman 0 0 0 7.1 f ~ Devil Canyon 0 0 5 6.0 Watana 1 1 13 5.0 Denali* 7 7 17 3.6 Basin Average 2 2 7 5.9 [ October 1982 L Talkeetna 172 172 72 -5.0 L Sherman* 189 189 -5.7 Devil Ganyon 200 200 95 -6.2 Watana 236 237 127 -7.6 Denali* 367 374 192 -11.8 L Basin Average 233 234 122 -7.3 November 1982 L Talkeetna 258 430 191 -8.5 [ Sherman* 301 490 -10.0 Devil Canyon 256 456 222 -8.9 Watana 304 541 279 -10.7 [ Denali* 471 845 376 -15.7 Basin Average 318 552 267 -10.8 [ r. L. l_~ -16 - f . s5/hh2 TABLE 3.2 NUMBER OF FREEZING DEGREE DAYS (°C) September 1982 -May 1983 (Continued) Average Historical** Record Mean Monthly Normal Air Temperature Monthly Accumu Ia ted Month (OC) December 1982 Talkeetna 230 660 407 -7.2 Sherman 274 764 -8.7 Devil Canyon 255 711 391 -8.2 Watana 324 865 468 -10.4 Denali* 477 1322 627 -15.4 Basin Average 312 864 473 -10.0 Januar}! 1983 Talkeetna 336 996 311 -10.8 Sherman* 340 1104 -11.0 Devil Canyon* 354 1065 325 -11.4 Watana 440 1305 402 -14.1 Denali* 630 1952 531 -17. 1 Basin Average 420 1284 392 -12.9 Februar}! 1983 Talkeetna 211 1207 224 -7.5 Sherman* 225 1329 -8.0 Devil Canyon 212 1277 254 -7.5 Watana 281 1586 289 -10.0 Denali 395 2347 416 -14.1 Basin Average 265 1549 297 -9.4 -17 - s5/hh3 TABLE 3.2 NUMBER OF FREEZING DEGREE DAYS (°C) September 1982 -May 1983 (Continued) Average Historical** Record Mean Monthly Normal Air Temperature Monthly Accumulated Month (oC) March 1983 Talkeetna 120 1327 107 -3.5 Sherman* 128 1455 -4.2 Devil Canyon 153 1430 147 -4.9 Watana 233 1819 223 -7.6 Denali 366 2713 302 -11.8 Basin Average 200 1749 195 -6.4 Aeril 1983 Talkeetna 15 1342 36 1.9 Sherman 21 1476 21 1.8 Devil Canyon 30 1460 75 0.8 Watana 65 1884 115 -1.1 Denali 81 2794 151 -2.3 Basin Average 42 1791 80 0.2 May 1983 Talkeetna 0 1342 0 9.1 Sherman 0 1476 0 6.9 Devil Canyon 0 1460 0 6.8 Watana 0 1884 9 5.3 Denali 0 2794 5 4.9 Basin Average 0 1791 3 6.6 * Partial Record -Some values are based on linear regression analyses. See Appendix A. ** Period of Record: Talkeetna Shermc:n Devil Canyon Watana Denali 1940-1983, only used 1980-1983 1982 -1983 1980-1983 1980-1983 1980-1983 -18 - r· [ L [ [ f- L s5/cc5 TABLE 3.3 NUMBER OF FREEZING DEGREE DAYS (°C) SEPTEMBER 1981 -May 1982 Mean Monthly Air Temperature Monthly Accumulated (oC) Se~tember 1981 Talkeetna 0 0 7.3 Sherman (No Data) Devil Canyon 12 12 4.4 Watana 33 33 4.0 Denali 40 40 3.2 Basin Average 21 21 4.7 October 1981 Talkeetna 29 29 2.0 Sherman (No Data) Devil Canyon 41 53 -0.4 Watana 72 105 -2.1 Denali 108 148 -2.8 Basin Average 63 84 -0.8 November 1981 Talkeetna· 205 234 -6.4 Sherman (No Data) Devil Canyon 255 308 -8.3 Watana 316 421 -10.4 Denali 389 537 -12.9 Basin Average 291 375 -9.5 December 1981 Talkeetna 367 601 -11.7 Sherman (No Data) Devii Canyon 363 671 -11.6 Watana 424 845 -13.7 Denali 514 1051 -16.5 Basin Average 417 792 -13.4 January 1982 Talkeetna 531 1132 -17.1 Sherman (No Data) Devil Canyon 528 1199 -17.0 Watana 622 1467 -20.1 Denali 732 1833 -25.2 Basin Average 616 1408 -19.8 -19 - r~ s5/cc6 r- TABLE 3.3 [' NUMBER OF FREEZING DEGREE DAYS (°C) SEPTEMBER 1981 -May 1982 (Continued) r Mean Monthly Air Temperature r, Month I~ Accumulated (oC) t_ Februar~ 1982 Talkeetna 285 1417 -9.9 L Sherman (No Data) Devil Canyon 344 1543 -12.1 Watana 365 1782 -13.0 [ Denali 525 2358 -18.7 Basin Average 380 1775 -10.7 I,, L March 1982 Talkeetna 161 1578 -5.0 [ Sherman (No Data) Devil Canyon 223 1766 -7.1 Watana 299 2081 -9.6 [ Denali 359 2717 -11.5 Basin Average 261 2035 -8.3 [ April 1982 Talkeetna 46 1624 0.1 [ Sherman (No Data) Devil Canyon 102 1868 -2.7 Watana 140 2221 -4.5 [' Denali 182 2899 -5.9 Basin Average 118 2153 -3.3 L May 1982 Talkeetna 0 1624 6.4 [ Sherman 0 6.4 Devil Canyon 0 1868 4.4 Watana 27 2248 2.3 Denali 15 2914 2.5 L Basin Average 8.4 2164 4.4 ~.,~ I -20 - L~ L s5/cc7 TABLE 3.4 NUMBER OF FREEZING DEGREE DAYS (°C) SEPTEMBER 1980 -MAY 1981 Mean Monthly Air Temperature Month I~ Accumulated (OC) Se~tember 1980 Talkeetna 0 0 7.7 ' Devil Canyon 1 1 3.5 Watana 4 4 3.5 Denali 4 4 4.7 Basin Average 2 2 4.9 October 1980 Talkeetna 14 14 2.1 Devil Canyon 45 46 0.2 Watana 74 78 -2.1 Denali 102 106 -2.9 Basin Average 59 61 -0.7 November 1980 Talkeetna 111 125 -3.5 Devil Canyon 154 279 -5.1 Watana 216 294 -7.2 Denali 269 375 -9.0 Basin Average 188 268 -6.2 December 1980 Talkeetna 623 748 -20.1 Devil Canyon 556 835 -17.9 Watana 656 950 -21.1 Denali 890 1265 -28.3 Basin Average 681 950 -22.0 -21 - [ s5/cc8 ,~ l ~ TABLE 3.4 l NUMBER OF FREEZING DEGREE DAYS (°C) SEPTEMBER 1980 -MAY 1981 (Continued) 1: Mean Monthly Air Temperature Month I~ Accumulated (oC) L January 1981 Talkeetna 66 814 -1.8 [ Devil Canyon 92 927 -2.5 Watana 143 1070 -4.5 Denali 181 1446 -5.5 [ Basin Average 121 1064 -3.6 February 1981 ,~, L Talkeetna 177 991 -6.1 Devil Canyon 205 1132 -7.3 [ Watana 221 1291 -7.9 Denali 328 1774 -11.8 Basin Average 233 1297 -8.3 [ March 1981 Talkeetna 40 1031 -0.4 r" Devil Canyon 65 1197 -1.8 Watana 136 1427 -4.3 Denali 181 1955 -5.6 [ Basin Average 106 1403 -3.0 April 1981 L Talkeetna 48 1079 -0.1 Devil Canyon 92 1289 -1.8 L W?,tana 141 1568 -4.3 Denali 190 2145 -6.2 Basin Average 118 1520 -3.1 [' ~ Ma~ 1981 Talkeetna 0 1079 10.0 l ' Devil Canyon 0 1289 8.7 Watana 0 1568 7.6 Denali 0 2145 7.1 [_ Basin Average 0 1520 8.4 L -22 - L I N w I "'t 0 c ~ • p ... 5 c l' L I .J MEAN MONTHLY AIR TEMPERATURE SEPTEMBER 1982 -MAY 1883 AND HISTORIC MEAN 10 -() ~ Ill 0 a: :::» ... c •10 a: Ill a. ::E Ill ... -10 a: c •10 10 -•ua-ea -mr-'tr., ...... Location: Talkeetna~ Alaaka Operator: National Weatner Service 10 -u ~ 0 Ill a: i! c -10 a: Ill a. :1 -teea-u = -ao -t'rA'!l!••••ee. 5 c -ao Location: Devil Canyon Weather Station Operator: R a M Consultants, Inc. 10 -f 0 Ill c :::» ... c -to a: Ill a. :1 Ill ·10 ... 5 c -ao -teh-ea -=='••••a•. Location: Watana Weather Station Operator: R a M Conaultants, Inc. -•eu-u (loo lllotorlc r•corll) Location: Sherman Weather Station Operator: R a M Consultants, Inc. -f Ill a: i! c a: Ill a. :1 Ill ... 5 c tO ·10 •10 •10 -l'tA'-'= ....... . Location: Denali Weather Station Operator: R a M Consultants, Inc. I ~ I "" 0 c .. • • " ,---- l • >-c a -f Ill Ill a: c Ill Q c z N Ill Ill a: "' FREEZING DEGREE DAYS MONTHLY TOTAL Cl) >-c a ~ Ill Ill a: c Ill a c z N Ill Ill a: "' 400 100 tOO 100 0 100 400 aoo 100 tOO 0 Location: Talkeetna, Alaaka Operator: National waathar Service Cl) >-c a -cY -Ill Ill a: c Ill a c ! Ill Ill a: "' Location: Davll Canyon Weather Station Operator: R & M Conaultanta, Inc. aoo 400 II D 1912-83 HISTORICAL AVERAGE Cl) >-c a ii -Ill Ill a: c Ill a c z N Ill Ill a: "' 400 100 100 100 0 :100·. 100 100 0 Location: Watana Weather Station Operator: R & M Conaultanta, Inc. Location: Sharman waathar Station Operator: R & M Conaultanta, l'!c. 700 (I) ~ 100 a f 100 -Ill Ill a: c ~ 100 c ! 100 Ill = 100 "' 0 ...... II . IIJII OCT I NOV I DIC I JAN I FEI(MAII( APIII MAY I r--'··.-.., J MONTH Location: Denali Weather Statton Operator: R & M Conaultanta, Inc. -E s z 400 MONTHLY PRECIPITATION DATA October 1982 -May 1983 -precipitation water equivalent c:J precipitation anowfaH fSJ maximul'n anow depth on ground @ 200 ~ ii: -CJ f o~~~~~~~~--~~~~~~~~._&8~~--~-.--- Locatton: Watana Weather Station Operator: R & M Consultants, Inc. 800 -E E 800 -z 0 -~ c .... 400 -A. -CJ w a: a. 200 Location: Talkeetna, Alaska Operator: National Weather ·service Figure a.a R&M CCNSULTANTS1 INC. 8NCit~~~ttt~••• o•OLGa••"'• IILANIW••• auiiV•vo•• -25-SUS/TNA JOINT VENTU.· ; s6/ii1 4.0 SUSITNA RIVER FREEZE-UP PROCESSES Freeze-up processes initiated in early October, 1982 and continued through final ice cover development in March 1983. This section describes the various types of ice covers that form on the Susitna River from Cook Inlet upstream to the proposed damsite at Watana. 4.1 Definitions of Ice Terminology and Comments on Susitna River Ice Some users of this report may not be familiar with standard terminology used in describing river ice and since a rather extensive description of ice processes on the Susitna River follows, a brief discussion on common types of ice observed on the Susitna is presented here. This is not intended to be a complete glossary of ice terms, and those interested in information on other types of ice should refer to the more definitive papers on river ice listed in Section 8 (e.g. Newbury 1968, Michel 1971, Ashton 1978, and Osterkamp 1978). Frazil -Individual crystals of ice generally believed to form when atmospheric (cold air) and hydraulic (turbulence) conditions are suitable to maintain a supercooled (<0°C) layer at the water surface (Newbury 1968, Michel 1971, Benson 1973, Osterkamp 1978), see Section 4. 2. Frazil Slush -Frazil ice crystals have st1·ong cohesive p1·operties and tend to flocculate into loosely packed clusters that resemble slush, (Newbury 1968). The clusters may continue agglomerating and will eventually gain sufficient buoyancy to counteract the turbulence and float on the water surface. This slush is highly porous. Samples collected at Gold Creek in October 1981 yielded a ratio of water volume to ice volume of 70-80 percent. Ice Constrictions -Slush ice drifts downstream at nearly the same velocity as the current. The velocity of the slush can be affected by surface constrictions caused by border ice shelves. These -26- r [ . [ L L L [ [ l. r . L L L r l. s6/ii2 constrictions generally occur in areas of similar channel configuration where the thalweg is confined to a narrow deep channel along a steep bank. The current exerts a steady frictional force on the underside of the the slush cover. When entering constricted areas, the slush is therefore forced to compact and the density of the ice increases. The slush ice continues to pass through the channel surface constriction and is extruded from the downstream end as a long continuous, unbroken ribbon of ice. The structural competence of the ice layer is greatly increased since the water filled interstices between the ice crystals have collapsed. As the layer of compressed slush accelerates away from the constriction, it begins to fragment into floes of various sizes, depending primarily on the flow distribution in the channel. Generally, the rafts break into floes averaging 2-3 feet in diameter unless an extremely turbulent reach is encountered where the floes disintegrate and emerge once again as small slush clusters. Ice Bridges When the air temperatures become very cold (e.g. -20°C), and/or the density of the compressed slush is high, then the viscosity of the floating ice will increase until it can no longer be extruded through a channel surface constriction. In this event the continuous slush cover over the water surface freezes resulting in an ice bridge. Ice floes contacting . the upstream (leading) edge of the ice bridge will either accumulate there or be subducted underneath the ice cover. The stability of ice against the leading edge is critically dependent on the water depth and velocity. Surface water velocities exceeding 3 ft/sec generally prevent ice accumulation, (Newbury, 1968). Snow Slush -Slush ice has been observed to form during heavy snowfalls, (Newbury 1968, Michel 1971, R&M 1982d). The influx of snow crystals dramatically increases the ice discharge. Upon contact with the water surface, the snow crystals undergo an immediate metamorphosis into slush which is indistinguishable from frazil slush. Observations at Gold Creek and Talkeetna indicate that the influence of snowfall on slush ice discharge is significant and could affect the -27- s6/ii3 rate of ice cover progression on the Susitna River below Talkeetna during years of low frazil generation. Figures 4.1 and 4.2 show the relationship between daily air temperature, snowfall and ice concentration at Talkeetna and Gold Creek respectively. The first occurrence of visible slush ice during the past season was on October 12, 1982, coincident with the first heavy snowfall of the year. It is interesting to note that the observed ice concentration does not correlate with air temperature, according to the relationships in the figures described above. The air temperatures at Talkeetna were not low enough ( -2. 5°C) to substantially increase the frazil ice concentration and although the air temperature at Denali was low enough ( -10°C) to generate ice, it could not have influenced the ice concentration at Talkeetna on the same day. Travel time between Denali and Talkeetna, a distance of more than 160 river miles, is approximately 1. 5 days at a flow velocity averaging 6 ft/sec. The calculated ice discharge for the 1()Qo estimated surface coverage at Talkeetna on October 12, 1982 is 30 cfs or approximately 2.5x106 cubic feet of ice per day. Assuming that little or no frazil was contributing to the slush ice because of high air temperatures, then it can be concluded that snow has a very significant influence on slush ice concentration and therefore also on the ice cover. Shore Ice or Border Ice -Initially, slush ice drifts into and covers the zero velocity flow margin against the river bank. Additional slush flowing downstream sometime contacts this f1·ozen ice and accumulates against it in a layer. This layer. affected by the flow velocity, will continue to move downstream, maintaining contact with the shore fast layer. If frictional forces of the water are overcome by the shear resistance between the ice layers, then movement stops and the slush layers freeze together. Shore ice will continue adding layers by this process until the ice extends far out into the river channel where flow velocities are in equilibrium with the shear resistance of slush ice. These ice layers often constrict the surface of the flowing water and present a barrier to floating slush ice. The constrictions have been observed to become so narrow that the slush -28- I ~ ' r~ L [ ~ [ r , [ : r: L r-, [- L L f ~ l [ [ l ' L l s6/ii4 ice must be extruded through under pressure. Flows along the shoreline of the Susitna are rarely placid enough for black ice formation, however thick layers (1-2 feet) of clear ice have been found to grow under the surface slush ice. Black Ice -Black ice forms initially as individual crystals on the water surface in lakes, zero velocity areas in rivers and underneath an existing ice cover (Michel, 1971). These crystals all develop uniformly in the same direction, with the c-axis of the crvstal perp.mdicular to the thermal gradient. This orderly arrangement results in a compact structure with relatively few crystal boundaries and thet·efore less potential for a structural failure in the ice sheet. Black ice developing in the absence of frazil crystals is characteristically translucent. This type of ice often grows into clear laye:·s several feet thick under the Susitna slush ice cover. In contrast, water saturated slush ice (such as most border ice) is opaque, that is, usually white or blue in appearance. Ice cover rigidity and structural competency is generally dependent on the initial ratio of water volume to slush ice volume (Newbury, 1968). Black ice, which contains no slush is therefore extremely strong (shear resistant) even in relatively thin layers. The large. well rounded crystals of drained slush ice, however, produce floes which are inherently weak and will easily fragment. Hummocked Ice -This is the most common form of ice cover on the Susitna. Essentially it is a continuous accumulation of slush, ice floes, and snow that progresses upstream during freeze-up. This process will be described in Section 4.3. 4. 2 Frazil Ice Development of an ice cover on the Susitna River is a complex process influenced by many variables and mechanisms that are not fully understood. The ice on this river is primarily a continuous accumulation of frazil slush and snow slush. It is therefore important -29- s6/ii5 to understand the relationship and significance of air temperature, water temperature, turbulence and suspended sediment to frazil ice generation. Little data on these variables has been collected. Frazil ice crystals are formed when water becomes supercooled. Supercooling is a phenomena by which water remains in a liquid state at temperatures below 0°C. Controlled, uniform laboratory conditions can supercool pure water to as low as -30°C. Under natural conditions, river water will supercool only a fraction of a degree below 0°C (Osterkamp 1978, Benson 1973) before frazil ice forms. Studies dealing with frazil formation have not established a mechanism to explain this order of magnitude difference in crystallization temperature. Theories on ice nucleation processes have been developed based partly on experiments conducted in cloud physics. Foreign particles are associated with the nucleation of ice crystals and rivers normally contain an abundance of suspended sediment and organic material. The Susitna River discharges tremendous volumes of silt and clay size particles prior to freeze-up whi,ch may initiate nucleation of ice. No specific studies have been conducted to date on the Susitna River to substantiate the relationship between frazil ice formation and suspended sediment. However, there is an apparent correlation between the first occurrence of frazil ice and a sudden, at time.s overnight, visual reduction of turbidity in the river water. During the month of September and generally, the first 3 weeks in October, Susitna water temperatures drop from 8.5°C to 0.5°C at Devil Canyon with similar temperature reductions at various other locations, (Table 4.1). With sustained air temperatures below Q°C, a thin layer of water will be cooled to the freezing point and ice crystals will form. Under quiescent conditions, the crystals will form on the water surface, eventually bonding together into a sheet of black ice, and continuing to grow vertically along the thermal gradient. Laboratory experiments have determined that flow velocities of only 0. 79 ft./sec. are necessary to mix the surface layer sufficiently to produce frazil (Osterkamp, 1978). These velocities are exceeded on the Susitna mainstem through most reaches so the water -30- ' ' r: r- [ ~ L r - I r-- I - [ [_ [ f' [' [' [ [ [ L [ ~ L_ L s6/ii6 body is continually being turned over. Under these conditions, the water can be supercooled to several hundredths of a degree below 0°C and frazil ice crystallizes. No substantial volume of ice has been observed on the Susitna until air temperatures fall below -10°C. Observation of first frazil occurrence, however, have only been made visually and on the Susitna, low volumes of frazil cannot be seen by casual inspection from a helicopter. For example, at lower ice discharges with air temperatures at -3°C, frazil crystals may not be forming in sufficient quantities to agglomerate into ice clusters large enough to appear on the water surface. Individual crystal~o tend to remain suspended in the flow, lacking the buoyancy required to counteract the turbulence. With colder air temperatures, (e.g. -10°C) more ice may be generated, increasing the concentration of ice crystals. Frazil ice has strong cohesive properties and tends to flocculate into clusters of several individual crystals. The frazil floes may in turn agglomerate with other floes to form masses of slush varying in size depending on flow conditions. Channel morphology seems to play an important role in controlling frazil agglomeration as indicated by ice plumes. These plumes are an early indicator of frazil ice and have been observed at several locations between Talkeetna and Vee Canyon where otherwise no ice was seen. The sites seem to have a similar channel configuration. Most occur at sharp river bends caused by outcrops protruding into the channel. The rock outcrops often create an eddy or slight backwater effect on the upstream side. Frazil floes, in suspension, are swept into these areas and swirl about, greatly increasing the potential of collision and adhesion with other floes. If the resulting slush balls gain sufficient mass and buoyancy, they encounter a higher velocity and more linear flow near the surface and are carried downstream. The slush exits floating in a long narrow stream which is rapidly dissipated by velocity and flow distributions. Any subsequent turbulence can re-entrain the slush into the flow rendering it once again difficult to observe. In September these ice -31- s6/ii7 plumes are often observed near Gold Creek, river mile (RM) 136, and Slough 9, RM 128.5 At these sites the air temperature is usually above freezing and once the ice surfaces it may melt. During September and October of 1982, the river water in the upper Susitna Basin (between Watana and Denali) was exposed to significantly colder temperatures as well as a longer cold period than the lower river below Talkeetna (Section 3). These meteorological trends and the shallow, turbulent, and swift flowing water common in the upper basin probably cause supercooling and the generatiC'n of frazil ice weeks before these processes occur in the Devil Canyon to Talkeetna reach. The volume of ice generated in the upper basin could have critical significance to the rate of ice cover development on the lower river below Talkeetna. It has been assumed in earlier reports that the majority of frazil ice was generated in the rapids of Devil Canyon, Watana Canyon and Vee Canyon. Although this holds true after November, the difference in the number of freezing degree days between Denali (370) and Talkeetna (170) in October suggests that the majority of the frazil slush accumulating against the leading edge downstream of Talkeetna originates in the upper river near Denali. On October 21, 1982 an attempt was made to verify this by estimating the ice discharge at various locations during a low level overflight from Talkeetna to Watana. The estimate WdS based on a method described by Michel ( 1971) in which the total ice discharge can be calculated using: -I =I n. v. h6B i:O I I where ni is the percentage of slush ice covering the channel surface, v. is the velocity, h is the total effective ice thickness and B is the I ice flow width. The percentage of ice and the flow velocity were estimated visually. The channel width was known from cross section surveys and used to estimate flow width. -32- [ : [ [ [ [ [ [ L [ [ L L L s6/ii8 Samples of slush ice were collected at Gold Creek during a heavy slush ice flow in mid-October, 1981. The percentage of water volume to ice volume in a 1 liter sample of slush averaged 60%. This value was then used for "e" in the following equation for calculating the total effective ice thickness (h): where h 0 is the thickness of the solid part of the floe and hf is the thickness of slush under the floe. A solid layer in the slush was never observed so h 0 = 0. The thickness of the slush was extremely variable so for this estimate an average of .5 ft was used. Velocities at the cross sections were consistently 4 ft/s with an ice flow width of 200ft. Thus, if ice was being generated in the reach between Talkeetna and Watana, then the ne\ ice discharge would be expected to decrease upstream. The final calculated ice discharges, however, consistently remained between 100-120 cfs all the way upstream to the confluence of Watana Creek. It was evident from this survey that rapids at Devil Canyon and Watana were not contributing significantly to the estimated total ice discharge of 3. 6 x 105 cu ft/hr on that day in mid-October. The majority of the ice was being generated further upstream beyond Watana Creek. Frazil ice crystals have a propensity for adhering to any object in contact with the river flow. \'/hen frazil adheres to rocks on the channel bottom it is commonly referred to as anchor ice. Anchor ice has been observed to develop into ice dams on the reach between Indian River and Portage Creek as a result of extreme accretion. Although these ice dams do not attain sufficient thicknesses to create extensive backwater areas, they increase the water velocity by restricting the cross sectional area. The configuration of the accretions is such that they may affect the stability of the flow, creating turbulence which could increase frazil generation. -33- s6/ii9 Anchor ice on the Susitna River is a relatively short term icing feature. On days with intense solar radiation or warm air temperatures, this ice has been observed to release from the channel bottom and float to the water surface, often carrying with it an accumulation of sediment. These surfaced anchor ice floes will drift downstream to eventually become part of an ice cover. Because of the high sediment concentrations (silt, sand and some small gravel), these ice floes remain easily identifiable even after they are incorporated into the advancing ice cover. 4. 3 Ice Cover Development This section discusses ice cover formation on the Susitna River from the mouth at Cook Inlet to the proposed damsite at Watana. For the purposes of this discussion, the river has been separated into 4 reaches: Cook· Inlet to Talkeetna, Talkeetna to Gold Creek, Gold Creek to Devil Canyon, and Devil Canyon to Watana. An additional section describing the unique freeze-up process in Devil Canyon is included. 4.3.1 Cook Inlet to Talkeetna The initiation of ice cover formation occurred suddenly when tremendous volumes of slush ice failed to pass through a channel constriction near RM 10, adjacent to Alexander. The exact date of this event is uncertain. On October 21, 1982 a field crew was operating at the mouth of the Susitna and reported flowing slush but not in substantial volumes. On October 26, 1982 aerial reconnaissance revealed the ice bridge at RM 10 as well as an unconsolidated ice cover up to RM 67 near the confluence of Sheep Creek. Thus, sometime between October 21 and October 26 the slush ice jammed at RM 10 and accumulated upstream 57 miles. Daily ice discharge estimates from Talkeetna (Table 4.2) showed a sudden increase in ice -34- ' f' r· L f ~ r - [ I L I l . ! I. [ L [ r: L [ c· r ' f ~ I L_ L s6/ii10 concentrations beginning on cu ft/hr and rising steadily October 21 with 1.3 x 105 to 5.8 x 105 cu ft/hr on October 26. Assuming that the ice cover began progressing upstream on October 22, then the progression rate of 11.5 miles per day is extremely fast, (see Figure 4.3). The ice cover was unconsolidated and few sections showed any compaction or telescoping. Open water was visible between the slush ice rafts. The cover appeared relatively thin (about 1 foot) although no measurements were made. Judging from the margin of flooded snow on the channel banks, the staging amounted to only .5 - 1 foot between RM 10 and RM 25 (Susitna Station). The flow discharge at Sunshine, based on provisional USGS estimates, ranged from 16,000 cfs on October 21 to 14,000 cfs on October 26. Upstream from RM 25 on October 26, the ice cover was no longer continuous. There was no ice cover, or evidence of ice progression on the Susitna near the confluence of the Yentna River. The Yentna was also completely free of drifting ice and shore ice. At RM 32, a loosely packed ice cover resumed and continued upstream to RM 67. Staging rarely exceeded 2 feet and large open water areas appeared frequently in the ice pack. Surprisingly little consolidation of the ice pack had taken place. An expltnation for this could be the shallow gradient of the channel through this reach. If velocities remain low then the ice will continue advancing simply by juxtaposition, advancing at a rate proportional to the ice discharge and channel configuration. Based on the rate of ice advance through this reach and the unconsolidated nature of the ice cover, it is probcoble that the Froude number at the leading edge remained well below the critical value of 0.08 so that no thickening of the ice cover was necessary for upstream ice progression. Slush ice observed at the leading edge was not submerging under the existing ice cover. From RM 67 to RM 97 near Talkeetna, the river remained free of shore ice even though a large volume -35- s6/ii11 of slush ice was continually drifting downstream. All of the major tributaries to the Susitna below Talkeetna were still flowing and remained ice-free. The discharge from these tributaries kept large areas at their confluences free of ice. On October 28, the existing ice cover received a layer of snow 183 mm deep. Observations on the 29th revealed no further compaction of the ice pack. Open water areas between the slush floes had frozen and were covered by snow. The ice pack remained confined to the thalweg channel with the exception of some side channel confluences where staging had created local backwater pools into which slush ice had drifted. The leading edge of the ice pack on October 29 was near RM 97, just upstream from the Parks Highway Bridge and adjacent to Sunshine Slough. The ice cover remained discontinuous however, with long open water areas at the Yentna River confluence near Susitna Station, the Deshka River confluence, Kashwitna Creek, and Montana Creek. These tributaries were still flowing but showed signs of an ice cover beginning to develop. At RM 76, the cover appeared extremely loose packed with individual slush rafts discernible within the cover. No movement was detected and the unconsolidated arrangement may have been stable. From R~ 76 upstream to RM 87 the ice cover was thin and discontinuous with long open water leads adjacent to Rabideux Slough and in a side channel that extended from ! mile below the confluence of Rabideux Creek downstream for about 1 mile. The ice pack was diverting water into this side channel which had begun to develop an ice cover by slush ice accumulation. The confluence with Montana Creek was flooded by an approximate 1 foot stage increase on the mainstem. Rabideux Slough was breached through two entrance channels. This was indicated by flooded snow only and no slush ice was flowing into t11e slough. The margin of flooded snow was particularly evident near the Parks Highway I [ [ f' I [ [ L L L s6/ii12 Bridge, where it extended all the way to the northwest abutment. The ice pack remained confined to the thalweg channel along the southeast end of the bridge. No gravel islands were observed to have been overtopped by the ice pack. No telescoping of the ice cover was evident and the ice pack remained in the narrow thalweg channel which in most areas constitutes only 20 percent of the flat, broad river channel. The leading edge had advanced to RM 95 by November 2 at a rate of 2.1 miles per day during the previous 4 days. The stage had increased substantially in . the vicinity of the leading edge causing water to flow out of the thalweg channel and flood the surrounding snow cover for several hundred feet. Many side channels had filled with water and the surface of the ice pack was near the vegetation line along the left (east) bank. The staging effects, however, were confined to the eastern half of the river, where the ch~nnel is split by a forested island. The channel along the west bank remained dry and snow covered. By November 4, river ice observers reported rapid and extreme stage increases as the leading edge approached Talkeetna (Table 4.2). An ice jam at the Susitna and Chulitna confluence had greatly reduced the volume of slush ice flowing past Talkeetna, slowing the rate of ice cover advance substantially. On November 2 a staff gage at Talkeetna had been dry, with the nearest open water more than 1 foot below ths gage. The staff gage was not again accessible until after consolidation and freezing of the ice pack on November 17 at which time the ice surrounding the gage corresponded to a reading of 3.6 feet. This represents a stage increase of over 4 feet at Talkeetna due to the ice cover advance. s6/ii13 After the initial ice cover formation, the remainder of the freeze-up process required considerably more time. Many of the side channels that were flooded by the increased stage in the mainstem gradually became narrower as shore ice layers built up along the channel banks and the flow discharge decreased. By early March, when discharge in the mainstem had dropped to less than 4,000 cfs at Sunshine, most open water had disappeared The continuous gradual reduction of flow also caused the ice cover to settle. Where the sagging ice became stranded, it conformed to the configuration of the channel bottom and created an undulating ice surface. Open water areas persisted throughout March in high velocity zones but were rare and generally restricted to sharp channel bends and shallow reaches in side channels which had originally been bypassed by the ice front. Some side channels and sloughs may receive a thermal influx form groundwater upwelling which would have been sufficient to keep these channels ice free. An open lead located at the end of the Talkeetna airstrip remained all winter although it gradually decreased in size. The following sequence summarizes the highlights and general freeze-up characteristics of the lower river from Cook Inlet to Talkeetna during 1982-1983. 1. Ice jam occurs at a channel constriction near the mouth of the Susitna during a high slush ice discharge. 2. Rapid upstream advance of an ice cover by slush accumulation. 3. Thin, unconsolidated initial ice cover. 4. Minimal staging, 1-2 feet up to Sunshine, then 2-4 feet near Talkeetna. -38- "'-J r-- \ r~ f l~ r - L r- [ r~- [ L L ~ [ 1 r~ -~ L L L L s6/ii14 5. No telescoping or spreading out of the ice cover due to consolidation. Ice cover generally is confined to the thalweg channel. 6. Tributaries continued flowing through December. 7. The following sloughs were breached with only minimal flow and little ice: a. Alexander Slough, upper end only, no through flow. b. Goose Creek Slough, no through flow. c. Rabideux Slough, minimal flow. d. Sunshine Slough, upper end only, no through flow. e. Birch Creek Slough, minimal flow. 8. Flooded snow along channel margins, variable widths. 9. High initial width discharges ( 16,000 cfs at Sunshine) and low final discharges ( 5,000 cfs). 10. No overtopping of gravel islands. 11. Some surface flow diverted into connecting side channels. 12. Ice cover sagging due to decreases in discharge. 13. Persistence of open leads in side channels and high velocity zones through March. -39- s6/ii15 14. Surface area decrease of open water by steady ice accumulations and decline of water table elevations. 15. Thick, thermal gradient or clear ice buildup under slush ice cover. 16. Minimal shore ice development due to lack of sufficiently cold air temperatures before ice cover advances. 4.3.2 Talkeetna to Gold Creek Slush ice was first observed in the Susitna River at Talkeetna on October 12, marking the beginning of freeze-up. Ice studies during previous years have observed slush ice as early as Se.ptember. In 1982, however, no field crews reported ice until after the snow stor·m on October 12. Ice continued flowing, in varying concentrations, through the reach between Gold Creek and Talkeetna until November 2, 1982 when an ice jam occurred at the Susitna and Chulitna confluence. This jam was the starting point for the ice cover that developed over this reach. Events during the 22 days prior to the ice jamming at the confluence are of significance and will be described first. This reach of river was subjected to colder air temper·atures and more flowing slush ice than the river below Talkeetna. Shore ice, therefore, had an opportunity to develop and at several locations actually extended far out into the channel, effectively constricting the slush ice flow. The higher velocities kept the slush ice moving through the constrictions and no ice bridges formed primarily because of the steeper gradient of this reach. At the Susitna and Chulitna confluence, the flow from the Susitna enters an area of lesser gradient and the velocity is reduced substantially. -40- l r ' ' r~ !' ~ ,~ r- l ' L ~~ L. r-- L [ [ [ L f. L L [ l ' l~. L s6/ii16 The Susitna River contributes approximately 80 percent of the ice while the Chulitna and Talkeetna Rivers combined produce the remaining 20 percent. The high (4-5 ft/sec)velocities of the Susitna keep the river channel open and push the slush ice downstream. After entering the confluence area, the masses of slush ice lose velocity and begin to pile up at the south bend of the Susitna adjacent to the entering east channel of the Chulitna. This process was observed on October 18, 1982. The slush was still moving easily through this area but was covering all of the open water for about 600 feet with a translucent sheet of compressed slush ice. The status of this ice accumulation was monitored frequently during October. On October 29, the ice was being compressed and barely kept moving by the mass of the upstream ice and by the water velocity underneath the cover. The ice through this area was no longer translucent but white since the slush had consolidated and increased in thickness su.fficiently to rise higher out of the water and partially drain. The ice constrictions being monitored on this reach were located near Curry (RM 120.6), Slough 9 (RM 128.5) and Gold Creek ( RM 135. 9). Slush ice was passing easily through these narrows on October 26 but was being compressed into long narrow rafts which usually broke up within several hundred feet. Unlike the confluence area, these constrictions were for·med by successive layers of frozen slush ice along the shore. A snow storm immediately preceded the formation of the ice bridge at the Susitna and Chulitna confluence. This storm may have caused a substantial local increase in ice discharge which could not pass through the channel at one time. The result was a sudden consolidation of the ice cover that compacted the slush and at some point became shore-fast. The cover remained stable long enough to freeze and increase -41- s6/ii17 in thickness. The majority of the incoming slush ice floes accumulated against the leading edge and the cover began advancing upstream. Approximately 10-20 percent of the slush ice submerged on contact with the upstream edge and either adhered to the underside of the cover or continued downstream. Ice discharge estimates were substantially lower after November 2 (Figure 4.1). The most dramatic effect of the ice consolidation at the confluence was flooding. The flow capacity of the ice choked main channel was greatly reduced and water spilled out from underneath the cover and flowed laterally across the river channel towards the opposite (north) bank. In addition, much water was diverted upstream by the ice jam and also flowed into the new channel. These diverted flows combined and entered the Chulitna east channel approximately 1, 500 feet upstream of the original confluence. The total estimated discharge of the diverted flow was 700-1000 cfs. The discharge at Gold Creek, on November 2, based on provisional USGS estimates, was 4, 700 cfs. Therefore, 15-20 percent of the total flow was bypassing the ice jam. There may have been substantial channel erosion caused by these diverted flows. Subsequent depth measurement through the ice located a isolated channel about 700 feet from the left bank that previous cross section surveys had not found. Only precise cross sectioning, however, could conclusively determine to what extent flow diversions were scouring localized channels. After the jam stabilized, the ice pack advanced slowly due to the increased gradient. The slush ice could no longer accumulate by simple juxtapostion as the high flow velocities submerged the slush on contact with the leading edge. The entire ice cover had to thicken in order to increase the stage and lower the velocity before ice could continue accumulating against the upstream edge. -42- l • ' \ j I ~~ t- ( -- [ ' r , I L, 1 ' L L [ [ L L L l' [ [ l L L s6/ii1S On November 9, 19S2 the leading edge was beyond RM 106 near Whiskers Creek and the ice advance appeared to have stalled. The upstream edge was located adjacent to the head of a flooded side channel. The ice cover was staging in order to overcome supercritical velocities at the leading edge, however, with every ice pack consolidation and subsequent increase in stage, more water poured into the side channel and effectively prevented any extensive backwater development upstream of the ice cover. This side channel needed to fill with ice before the mainstem ice pack could continue the advance. The water being diverted into the side channel contained a high ratio of slush ice to water volume since only the surface layer of the mainstem flow was affected and therefore, the channel quickly became ice-filled. The rate of ice advance was 1. 6 miles per day for thirteen days after passing Whiskers Creek. On November 22 the leading edge was :r.:tuated adjacent to Slough SA with the total discharge, estimated from Gold Creek, at 3,300 cfs, a decrease of 900 cfs since November 9. The ice cover had staged approximately 3.4 feet and was overtopping the berm at the head of Slough SA. At the mouth of Slough SA, near Skull Creek, the estimated discharge was 13S cfs. Much slush ice was carried in the flow and accumulated in low velocity pools. Within 5 days this slough had developed an ice cover of consolidated slush from the mouth to the head near RM 126.5. However, the cover was extremely unstable and as the water level dropped in the slough, the ice collapsed over the channel and eventually disappeared, leaving 1-2 foot layers of stranded ice on gravel bars and open water in long narrow leads. The ice cover was very slow in advancing through the shallow section of river between Sloughs SA and 9. On December 2, a sudden rise in the water table at Slough 9, recorded electronically in a ground water well, indicated the proximity -43- s6/ii19 of the leading edge (Figure 4.4). The well was located adjacent to RM 129.5 giving an advance rate of only 0.3 miles per day for the previous 10 days even though high frazil slush discharges were estimated at Gold Creek (Figure 4.2). This may reflect the consequences of the staging into Slough SA which were similar to those observed in the side channel near Whiskers Creek and described earlier. On December 9 the leading edge had reached RM 136, just downstream of the Gold Creek Bridge. The ice cover advance was stalled here and remained for over 30 days as the ice needed to accumulate in thickness before it could stage past this high velocity channel constriction. Ice discharges estimated at Gold Creek steadily decreased through December primarily because the upper river was freezing over, eliminating the air/water interface needed for frazil production. Finally, on January 14, 1983 the leading edge crept past the Gold Creek Bridge at a rate of 0.05 miles per day. The discharge on January 14 at Gold Creek, based on provisional USGS estimates, was 2,200 cfs, see Tables 4.3 to 4.6. The processes of ice cover telescoping, sagging, open lead development and secondary ice cover progression are important characteristics through this reach and deserve comment. Telescoping occurs during consolidation of the ice cover. When the velocity at the leading edge is subcritical, ice floes drifting downstream will contact the edge, remain on the surface, and accumulate upstream by juxtaposition at a rate proportional to the> concentration of slush ice in the flow and channel width. This buildup will continue until a critical velocity is encountered and the leading edge becomes unstable with ice floes submerging under the ice cover. This accumulation zone can be extremely long and is generally governed by the local channel gradient, amount of staging -44- ['' L_ I , [ [ [ [ [ [ [ L s6/ii20 and extent of the resulting backwater (Figure 4.3 and Table 4.8). The pressure on a thin ice cover increases as ice mass builds up and higher velocities are reached in conjunction with upstream advance. At an undetermined critical pressure, the ice cover becomes unstable and fails. This sets off a chain reaction and within seconds the entire ice sheet is moving en masse downstream. This represents the consolidation phase of ice cover stabilization. Several miles of ice cover below the leading edge can be affected by consolidation. The results of this process are a shortening of the ice cover, substantial thickening as the ice is compressed, a stage increase, and telescoping. The stage increase is caused by the ice thickening which creates a local restriction to flow. The telescoping occurs only during each consolidation. As the ice compresses downstream, tremendous pressures are exerted on the ice cover below the accumulation zone. Here the ice mass will shift to relieve the stresses exerted on it by the upstream cover, often becoming thicker in the process. This will tend to further constrict the flow resulting in an increase in stage. As the stage increases, the entire ice cover lifts and any additional pressures within the ice cover can then be relieved by lateral expansion of the ice across the river channel. Generally this process can continue until the ice cover has expanded bank to bank or encounters some other obstruction such as gravel islands on which the ice becomes stranded. The ice cover over water filled channels will continue to float. Because of constant contact with the flowing water, the ice cover erodes rapidly, sagging at first and eventually collapsing. In some reaches these open leads can extend for several hundred yards. The lengths and widths of these leads, as well as rates of collapse and secondary ice cover -45- s6/ii21 development can be determined from aerial photographs (Table 4.9). A secondary ice cover generally accumulates in the open leads and usually completely closes the open water by the end of March. The process is similar to the initial progression except on a smaller scale. Slush ice begins accumulating against the downstream end of the leads and progresses upstream. Generally it takes several weeks to effect a complete closure. Ice cover sagging, collapse, and open lead development usually occur within days after a slush ice cover stabilizes. A steady decrease in flow discharge gradually lowers the water surface elevation along the entire river. Also, the staging process which had raised the water surface within the thalweg channel tends to seek an equilibrium level with the lower water table by percolating through the gravels of the surrounding terraces. Percolation of river water out of the thalweg channel and the subsequent charging of the surrounding water table is currently under study. This process is being documented by recording the relationship between mainstem water surface elevations and relative stage fluctuatons in groundwater wells located on terraces near Slough 9, (Figure 4.4). Examination of aerial photographs of the sloughs taken during the ice cover advance up the mainstem revealed an increase in the wetted surface area. This increase was due to a rise in the water table since the sloughs are generally isolated from the mainstem at discharges of less than 25,000 cfs and the average discharge at Gold Creek in December is under 4,000 cfs. Many sloughs receive flow from groundwater seeps througho••t the winter. This continuous thermal influx (4°C) prevents a stable ice cover from forming. The seeping water originates from the unconsolidated gravels underlying the surrounding -46- •\ ,~ [ L L L: L [ I , [ r- L r, L [~ t~ r L [ [ l_ " L L s6/ii22 terraces and river bed. This intragravel watertable tends to permeate through the interstices at a rate dependent on the porosity and gradient of the gravel bed. If a scarp or channel should intersect this riverine watertable at an elevation below the local water surface then seeps will appears along the bank, or fill the intersecting channel. The water surface in the channel will then reflect the adjacent watertable elevation. Once exposed the water will follow the shallow gradient of the slough. This relatively warm, laminar flow will develop ice along the margins which may constrict the surface area to a narrow lead. This lead however, rarely freezes over and often extends for thousands of feet downstream, (Table 14). Open water was observed all winter in the following sloughs above the Chulitna confluence: Slough 7 Slough SA Slough 9 Slough 10 Slough 11 Slough 16 Slough 20 Slough 21 Slough 22 As previously described, Slough SA was the only slough breached by slush and consequently the only one to develop a continuous ice cover. The thermal influence of groundwater however, quickly eroded through the frozen slush ice cover and an open lead remained for the duration of winter. The 1982-1983 freeze-•Jp characteristics on the Susitna River between Talkeetna and Gold Creek are summarized as follows: -47- s6/ii23 I( _l I 1. Frazil ice plumes appearing as early as September but more commonly, in early October. 2. Velocities between 2-5 ftlsec. 3. Discharges at Gold Creek ranging from 4,900 cfs on November 1 to 1, 500 cfs by the end of March. 4. Ice jam initiating the ice cover progression from the Susitna/Chulitna confluence. 5. Gradually decreasing rate of ice advance from 3.5 miles per day near the confluence to 0.05 miles per day at Gold Creek. 6. Flow diversions into side channels and sloughs. 7. Ice constrictions by border ice growth. 8. Staging, commonly from 2-4 feet. 9. Ice pack consolidation. 10. Telescoping of ice cover laterally across channel. 11. Sagging ice cover. 12. Open leads and secondary ice covers. 13. Berms breached at Slough SA. 14. Staging effects on the local water table. 15. Thermal influx by groundwater seepage prevents ice cover formation in sloughs that are not breached and inundated with slush. -48- ... ,~ ~- r I I r··· I l ' I L r L r~ L f" L [ l-- [ r~ L L [ L L J L l __ s6/ii24 4.3.3 Gold Creek to Devil Canyon The freeze-up processes affecting this river reach are vastly different from those responsible for ice cover development below Gold Creek. Although the air temperatures here do not vary considerably from Sherman or Talkeetna, this reach undergoes much shore ice growth, development of anchor ice dams, and overflow primarily because of the long period required for the ice pack to advance into this reach. In fact, most of this reach had frozen over by other means before the leading edge of the ice progressed past Gold Creek. Therefore, the leading edge was extremely difficult to follow and eventually became indistinguishable just below the Indian River confluence. Because short-term changes in ice cover development in this reach are difficult to detect, a description of the general processes involved rather than a chronology is provided here. The most significant features of freeze-up between Gold Creek and Devil Canyon are wide border ice layers, ice accretions on rocks surrounded by border ice, and formation of ice covers over eddies. Gradually, the border ice layers constrict the channel to a width of 20-30 feet before they fill with slush and freeze over. Frazil and frazil slush tends to be drawn into the turbulent eddies behind large boulders in the streamflow. These eddies can have near zero velocities on the surface, so often the floating slush adhered to the rock or to other slush ice and freezes. This surface layer of ice may continue accumulating slush until the entire eddy area is frozen over. Ice dams have been identified at several locations below Portage Creek. Generally, the dams form when the rocks on which the frazil adheres are located near the water surface. When air temperatures are cold ( < -10°C), the ice covered -49- s6/ii25 rocks will continue accreting additional layers of frazil until they break the water surface. These dams effectively increase the water turbulence which may, in turn, stimulate frazil production and thus accelerate ice dam formation. The ice dams are often constricted by border ice. This creates a backwater area by restricting the streamflow so that it can only pass over the ice dam. This subsequently causes extensive overflow onto the border ice. The overflow will bypass the ice dam and re-enter the channel at a point further downstream. Within the backwater area, slush ice accumulates in a thin layer from bank to bank and eventually freezes. An ice bridge generally forms early in November just upstream of the Portage Creek confluence. This ice bridge does not, however, initiate an ice cover progression because of its proximity to a shallow rapids with velocities supercritical for ice cover formation. This reach from Gold Creek to Devil Canyon freezes over gradually and much later than the lower river. It is generally ice covered by early March, a full two months after the river downstream of Gold Creek has developed a stable ice cover. The delay can be explained by the relatively high velocities encountered despite the low discharges and the absence of a continuous ice pack pr·ogr·ession through the reach. Also, the relatively warm discharges from Portage Creek and Indian River tend to keep the river free of ice until the flows from these tributaries become insignificant relative to the Susitna discharge. To summarize, the following are the significant freeze-up characteristics of the river reach between Gold Creek and Devil Canyon. -so- ,, r I I l r l ' r l r r- l ' r I l r . L L L [ L L L r L r L L r L~ [ L L s6/ii26 ' / , ... "' 1. Steep gradient, high velocities, single channel. 2. Minimal continuous ice cover progression, usually only formation of local ice covers separated by open leads. 3. Late freeze-over, generally in March. 4. Extensive border ice growth, very wide layers of shore-fast ice. 5. Constricted channel, narrowed substantially by border ice. 6. Ice dams create local backwater areas which form ice covers. 7. Ice covers over eddies which form behind large boulders in streamflow. 8. Some telescoping, usually not widespread. 9. Minimal staging. 10. Extensive overflow. 11. Few leads opening afte•· initial ice cover. 12. No sloughs breached, no diverted flow into side channels. 13. Minimal ice sagging. 14. Thermal influx by groundwater seeps keeps sloughs open all winter. -51- s6/ii27 4.3.4 Devil Canyon (to Devil Creek) The Geophysical Institute of the University of Alaska, Fairbanks, furnished a time-lapse camera so that the ice cover formation in Devil Canyon could be documented. Ice processes occurring in this area have not been well understood since direct observadon is often impossible. The camera was mounted on the south rim of the canyon, adjacent to the centerline of the proposed dam. The reach to be filmed extended downstream of this site for approximately a half mile (Figure 4.5). This area seems to accumulate the thickest ice cover not only in the canyon but also on the entire Susitna River. Surveys conducted in the canyon during the previous 2 winters have measured ice shelf thicknesses up to 23 feet ( R&M 1981c). This thickening is known to have occurred in stages, each adding a new layer of ice on top of the existing cover. The duration and mechanism of this event could only be determined by direct observation of each ice flood. The sequence of events was therefore filmed by a remote, 8 mm movie camt!ra programmed to expose 20 frames every hour on the hour. The camera was installed on October 18, 1982 and was allowed to run continuously until February 7, 1982. On the day of installation, one ice advance and subsequent ice cover collapse had already occurred, depositing approximately 2 feet of ice on the boulder strewn channel banks. The following chronological sequence of events was compiled from examination of the film. The descriptions will begin on a daily basis when much ice activity was documented and taper to weekly and then monthly descriptions as fewer changes were observed. Air temperatures (mean daily °C) were obtained from the meteorological record of the Devil Canyon weather station. Streamflows are provisional estimates from the Gold Creek Station and are subject to revision by the U.S. Geological Survey. Ice thicknesses are estimates -52- f i I [ - I I- ~~ r- I_ f r ~ L [ [ [ L L ~~ [ [ L r L f L [ __ s6/ii28 from the film record. Measurements were attempted during ice formation, however, the ice cover remained too unstable for helicopter landings. October 18, 1982 Air temperature -5.0°C, discharge 6, 720 cfs. The channel appeared open with no ice bridges and no constrictions. There was 1-2 feet of shore-fast ice on the channel banks. October 19 -Air temperature -3.2°C, discharge 6,900 cfs. It was snowing heavily and the channel was partially obscured. It appeared to be completely filled with slush ice with no open water visible. Staging of at least 3-4 feet was evident. The channel remained ice covered throughout the day and the snow ended about 2 p.m. October 21 Air temperature -9.5°C, discharge 6,500 cfs. No significant changes as the channel remained ice covered all day with no open leads appearing. The weather was clear and sunny with swaying trees indicating high winds. October 22 -Air temperature -9.6°C, discharge 6,200 cfs. The ice cover began to sag in the center of the channel. The water level remained relatively high and the depression filled with water. This was probably not overflow, but instead the result of ice dropping below the water surface. The sagging center of the ice cover rapidly eroded and lengthened. The sides of the now open lead continued to calve off into the open water and the ice fragments disappeared. October 23 -Air temperature -9.8°C, discharge 6,000 cfs. It snowed heavily early in the morning tapering off around 10 a.m. Open leads were clearly visible in the high velocity reaches. Water saturated ice remained in some areas of lower -53- s6/ii29 velocity where erosional forces were not as severe. Little change was noticed during the day. October 24 -Air temperature -10.6°CI discharge 51900 cfs. large volumes of frazil were flowing in the open channel. An ice cover had again formed over the downstream portion of the open water lead. The upper portion remained open where apparently the water velocities were sufficiently high to prevent further ice cover progression at the prevailing ice discharge. During the day I the ice cover over the lower reach rapidly deteriorated by sagging and erosion. The floating ice cover was now sagging so far down that it sheared vertically from the shore-fast ice and floated within the open lead (Photo 21). This subjected the fragmented ice cover to the full velocity of the water which quickly eroded the ice away. The floating ice seemed to ride very low in the water 1 at times submerging completely. This is probably· due to the high porosity of the slush ice which initially formed the cover. October 25 -Air temperature -12.8°C, discharge 5, 700 cfs. There were no apparent changes as part of the channel was still partially covered and the remainder was choked with floating water saturated ice. Ice shelves on the banks were approximately 3-4 feet thick. October 26 -Air temperature -15.4 °C, discharge 5,600 cfs. The images of the canyon were obscured by heavy fog but the channel seemed to be ice covered with no open leads discernible. October 27 -Air temperature -19.1°C 1 discharge 5,400 cfs. There were no apparent changes. The ice cover remained intact and no water was visible. -54- [ [ [ [ L r l . s6/ii30 October 28 -Air temperature -13.2°C, discharge 5,300 cfs. Overnight, an open lead developed in the upstream rapids section. No further changes were noted on this day. October 29 -Air temperature -13.3°C, discharge 5,200 cfs. Fog again partially obscured the images. The open lead at the upstream end of the reach expanded in width and length. It appeared to be open for its entire wetted width and no overhanging ice shelves remained. This open water reach extended upstream out of the field of view. Another open lead about 300 feet downstream of the upper lead continued to increase its length by collapsing at both ends. By the end of the day, the two open leads had extended to within 50-75 feet of each other. October 30 -Air temperature -19. l°C, discharge 5,100 cfs. The first hour of daylight showed a long open lead partially obscured by fog. Apparently, the two leads of October 29 merged overnight when the ice bridge separating the leads collapsed and formed a narrow channel. The channel then widened considerably and the downstream end was located just above the south river bend. The upstream end was not visible, however, the upstream reach through the canyon is generally open because of extreme turbulence and high velocities. October 31 -Air temperature -15.9°C, discharge 4,900 cfs. The channel constriction of October 31 closed again, separating the open water reaches by about 75 feet of ice. This indicates the location of the deep pool surveyed in 1981, where flow velocities tend to allow gradual accumulation of frazil slush against the channel banks (R&M, 1981c. About 1 p.m., this ice closure began to erode along the left bank. November 1 -Air temperature -4.5°C, discharge 4,800 cfs. The first exposure of the day revealed one long open lead -ss- s6/ii3'\ running almost the entire length of the visible canyon. The border ice shelves were the only ice remaining within this reach of the canyon. These appeared to have thicknesses exceeding 10 feet in some places, particularly at the upstream channel constriction. This is also usually the first area to bridge over. November 2 -Air temperature -5.1°C, discharge 4, 700 cf!:. A high volume of ice seemed to be flowing and an ice cover was accumulating in the lower canyon reach. The channel at the most downstream end was filled with slush. Several advances of 20-30 feet were visible during the day. These were followed by consolidation phases during which the ice cover was compressed and the net stage increased. November 3 -Air temperature -7.8°C, discharge 4,600 cfs. The ice cover advanced about 100 feet overnight. The-cover appeared to be thin and did not come close to tht. top elevation of the shore ice. Although much ice was evidently flowing, it all seemed to be submerging underneath the existing cover and not accumulating against the leading edge. This indicates that the ice cover was thickening at some point downstream. No appreciable upstream advance occurred on this day. November 4 -Air temperature -2.9°~, discharge 4,500 cfs. The ice cover had not advanced since the previous day but, instead, has thickened and staged substantially. In the lower reach, the difference in elevation between the top of the shore ice and the ice cover in the channel was no less than 2 feet. November 9 -Air temperature -7.1°C, discharge 4,100 cfs. little change was apparent in the ice regime despite a high volume of flowing ice. -56- [ L [-, [ [ L [ [ [ l I L s6/ii32 November 14 -Air temperature -6.2°C, discharge 3,800 cfs. The past 5 days showed little change in the shape or size of the open lead except for minor advances of 10-20 feet at the leading edge. These subsequently consolidated, relocating the ice front to its original position. On this day the ice cover finally closed the lower canyon reach. The upper lead remained open but a very high volume of slush ice could be seen flowing within the lead. This sudden increase in slush ice concentration was probably related to the rapid ice cover formation in the lower canyon. A correlation between snowfall on November 14 and ice discharge can be seen and is illustrated in Figure 6. November 15-21 -Discharges from 3, 700 cfs down to 3,400 cfs. Ice covers that formed repeatedly over the lower canyon reach but seemed to be extremely unstable. The . covers typically lasted only a few days and destruction generally occurred coincident with a decrease in ice discharge. The duration of ice cover deterioration was variable and probably depended on velocity as well as climatic conditions. December -January -Discharges fell from 3,000 cfs down to 2,000 cfs. No new processes were observed· during this period. Snowfalls continued to stimulate heavy frazil ice loading and subsequent ice cover progression through the canyon. The ice cover over the reach finally stabilized. The final 20 days of filming showed that the ice cover over the lower reach began from the border ice constriction and extended beyond the south river bend. This cover did, however, eventually develop cracks. A sag appeared, the ice finally collapsed, and open water showed through. The final exposures, in February, clearly showed the ice cover beginning to fail along its entire length. This seems to indicate that the ice covers within this narrow and turbulent river reach are inherently unstable. -57- s6/ii33 The number of ice cover advances totalled 6 on the lower reach and 3 on the upper. This difference is due primarily to a steeper gradient and thus, higher velocities and turbulence in the upper section. Only during extreme ice discharges did this reach form an ice cover. The initial ice cover developed in October over both reaches but rapidly eroded away ·leaving only remnant shore ice. The second major ice cover event occurred in December with the final ice cover forming in January. All of the major ice advances were related to heavy snowfalls. A storm in January left an ice cover on the lower reach which appeaJ·ed to be stable. The low discharges in January probably resulted in subcritical velocities which could explain the longevity of this ice cover. Some interesting aspects about the freeze-up of Devil Canyon were observed over the past season and deserve comment. Certainly the most unique characteristic of Devil Canyon ice is the great ice thickness. With each ice event, more ice is deposited on top of the relatively stable shore-fast ice. The shore-fast ice creates an unnaturally narrow channel which essentially decreases the water and slush ice-carrying capacity of this reach. Consequently, when staging occurs the slush must rise and therefore, even with relatively small fluctuations of flow, extreme staging may occur. The width of the winter channel is controlled by the steep canyon walls. Shore ice is initially fot·med by an ice cover anchoring to boulders along the channel banks. This shore-fast ice was not affected by winter flows since the ice was deposited well above the normal water surface. Only during rapid staging events was the flow constricted. Apparently, the rapid rise and decline of the water surface does not erode the shore ice significantly. Certain sections within Devil Canyon are the first areas on the Susitna to form an ice bridge and develop an extensive ice cover. Ice covers of one mile in length have been -sa- r f' L [ [ [ r: [_, L L L s6/ii34 observed to form about two miles below the Devil Creek confluence as early as October 12, despite relatively warm air temperatures. To summarize the highlights of freeze-up in Devil Canyon: 1. Narrow, confined channel with high flow velot;i•;t•as and turbulence. 2. Early formation of ice bridges and loosely packed slush ice covers. 3. Formation and erosion of ice covers several times during the winter. 4. Inherently unstable ice covers, eventual collapse long before breakup. 5. Extreme staging and ice thicknesses up to 23 ft. 4.3.5 Devil Canyon to Watana This section of the river has not been thoroughly studied. However, some general comments on the freeze-up processes affecting this reach can be made. These are based mostly on ice formations observed during breakup after the snow had melted off of the ice cover. An accumulation of border ice layers is primarily responsible for th~ ice cover development. The border ice often constt·icts the open water channel to less than 30 feet. The slush ice then jams in between the shore-fast ice and freezes, forming an unbroken, uniform ice cover across the river channel. However, since this process does not occur simultaneously over the entire reach, a very discontinuous ice -59- s6/ii35 cover results. Open leads generally abound until early March when the combination of snowfall and overflow closes most of the openings. Characteristics of freeze-up between Devil Canyon and Watana are summarized as follows: 1. Extremely wide accumulations of border ice layers. 2. Gradual filling of the narrow open channel with slush which freezes and forms a continuous ice cover. 3. Extensive overflow and flooded snow. 4. Minimal staging or telescoping. 5. Low discharges. 6. Shallow water and moderate velocities. 7. Minimal ice sagging, few leads opening after initial freeze-up. 8. Extensive anchor ice with high sediment concentrations. 4.3.6 Ice Cover at the Peak of Development The ice cover on the Susitna River is extremely dynamic. From the moment that the initial cover forms, it is either thickening or eroding. Slush ice will adhere to the underside of an ice cover in areas of low velocity and cold temperatures will subsequently bond this new layer to the surface ice. Table 4. 7 lists Susitna ice cover thicknesses from Watana to the Chulitna confluence. These measurements represent the cover at maximum development in 1983. -60- r: [~ ~-- r-- r , !_ r: [ r-; L (' L [ r- L L [ [ [ f : l_ ~ L i L s6/ii36 If the ice cover could ever be considered stable it would be at the height o~ its maturity in March. During this period of the winter, snowfalls become less frequent and very little frazil slush is generated. The only water contact with air occurs at the numerous open leads which persist over turbulent reaches or groundwater seeps. These are usually of short length and therefore minimal heat exchange takes place. Table 4.9 presents the locations and dimensions of most annually recurring leads between Sunshine and Devil Canyon. Discharges in March are generally at the yearly record low, reducing the flowing. Water to a shallow and narrow thalweg channel as indicated by a depression in the ice cover. The depressions fot·m shortly after ice cover formation when the compacted slush ice is flexible and porous. Water levels decrease through March and the floating ice cover is often grounded on the river bottom. Water gradually perc9lates out of the cover, and alternating layers of bonded and unconsolidated ice crystals fot·m within the ice pack when the receding level of saturated slush freezes at extreme air temperature. The result is the fot·mation of rigid layers at random levels, the layers representing the frequency of critically cold periods. By the end of March, the Susitna River ice has essentially metamorphosed into a stiff and impet·meable cover. -61- s5/ii1 TABLE 4.1 SUSITNA RIVER SURFACE WATER TEMPERATURE PROFILE* SEPTEMBER 1982 -OCTOBER 1982 Water Tem~erature °C Mean September 1-30, 1982 Min. Max. Mean 9/1/82 Above Yentna River, RM 29.5 4.0 9.5 7.0 8.5 Park Highway Bridge, RM 83.9 4.1 9.0 6.3 8.0 Talkeetna Fish Camp, RM 103.0 4.4 9.9 7.0 8.7 Curry, RM 120.7 4.5 9.1 6.8 8.4 LRX-29, RM 126.1 3.8 10.0 6.8 8.6 Devil Canyon, RM 150.1 4.0 9.5 6.8 8.5 Water Tem~erature °C Mean October 1-17, 1982 Min. Max. Mean 10/1/82 Above Yentna River, RM 29.5 0.0 5.0 1.9 4.8 Parks Highway Bridge, RM 83.9 0.2 4.6 1.2 4.6 Talkeetna Fish Camp, RM 103.0 0.2 4.9 1.2 4.7 Curry, RM 120.7 LRX-29, RM 126.1 Devil Canyon, RM 150.1 0.0 4.0 1.8 3.5 Mean 9/31/82 4.7 4.6 4.9 4.5 4.0 4.0 Mean 10/31/82 0.0 0.2 0.2 0.5 * These data were obtained from published reports by Alaska Department of Fish & Game, Susitna. Temperatures were recorded on a thermograph at all sites except Devil Canyon which was recorded electronically, (ADF&G, 1982). -62 - [ ~-- [ [ l. L L L "J ' -' s5/cc4 1. 2. 3. Date October J982 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 November 1982 1 2 3 4 5 6 7 8 9 10 11 12 TABLE 4.2 SUSITNA RIVER AT TALKEETNA FREEZEUP OBSERVATIONS ON THE MAINSTEM Staff Discharge Gauge(1 ) @ Sunshine(2 ) ~Ice (ft) (cfs) in Channel 1.65 20,000 0 1.68 20,000 10 l.S§ 20,000 0 1.42 19,000 30 1.25 18,000 30 1.30 17,000 25 1.24 I .':·QOO 25 1.23 17 ,bi)() 25 1.20 17,000 20 1.15 16,000 30 0.98 16,000 60 0.97 16,000 70 0.40 15,000 75 15,000 80 -1.00 14,000 90 -1.50 14,000 90 -1.50 14,000 90 -1.50 13,000 85 -1.50 13,000 80 -1.50 13,000 80 2.50 12,000 80 1.54 12,000 60 1.52 12,000 50 11 ,000 40 11,000 50 3.60 (Top of ice after freezeup) 50 3.60 11,000 70 3.60 11 ,000 80 3.50 10,000 100 3.60 10,000 100 3.60 9,800 100 3.30 9,800 100 Relative elevations based on an arbitrary datum. Provisional data subject to revision by the U.S. Geological Survey, Division, Anchorage, Alaska. Visual estimation based on one daily observation usually at 9 a.m. -63 - Ice Thickness (ft) .01 .03 .09 .09 .09 .10 . 10 .10 .20 .20 .30 .40 .40 .40 .40 .40 .40 3.30 3.30 3.30 3.30 3.30 3.30 3.30 Water Resources S5/dd1 TABLE 4.3 SUSITNA RIVER AT GOLD CREEK FREEZE-UP OBSERVATIONS ON THE MAINSTEM October 1982 Gold Creek Mean Air Water Ice in Border Ice Snow Discharge ( 1 ) Temperature (2) Tempera Lure ( 3) Channel ( '" Thickness Depth Date (cfs) (oC) (oC) Ill ( ft l lf..U_ Weather Oct. 19 6900 -1.4 0.65 50 slush 0.6 Snow 20 6800 -5.0 0.80 ItO slush 0.6 Cloudy 21 6500 -5.6 1.00 60 slush 0.6 Windy/Sunny 22 6200 -4.4 0.90 60 0.3 0.6 Windy/Sunny 23 6000 -9.2 0.80 65 0.3 0.6 Windy/Sunny 211 5900 -7.8 1. 01) 50 0.3 0.6 Partly Cloudy 25 ~700 -10.0 1.00 60 0.3 0.6 Cloudy 26 ~600 -14.1J 0.50 60 0.3 0.6 Cloudy 27 51100 -13.6 0.20 65 0.4 0.6 sunny 28 5300 -·1.8 0.00 65 0.4 1.0 Snow 29 5200 -6.9 0.00 70 0.5 1.5 Snow 30 2100 -18.3 0. HI 70 0.7 1.5 sunny 31 4900 -17.8 o.oo 70 0.7 1.5 sunny 1. Provisional data subject to revision by the U.S. Geological Survey, Water Resources Division, Anchorage, Alaska. 2. Average value of the days minimum and maximum temperature. 3. Based on one instantaneous measurement, usually taken at 9 a.m. daily. ''· Visual estimate based on one. instantaneous observation, usually at 9 a.rn. daily. '' sS/dd2 TABLE 4.4 SUSITNA RIVER AT GOLD CREEK rREEZE-UP OBSERVATIONS ON HIE MAINSTEM November 1982 Gold Creek Mean Air Water Ice in Border Ice Snow Discharge (1) Temperature (2) Temperature ( 3) Channel (4) Thickness Depth Date (Cf§) ( oc) (°Cl 1%1 (ft.) .u:.u_ Weather Nov. 1 4800 -2.2 o.oo 70 0.9 1. 5 Windy/Cloudy 2 lf/00 1. 1 0. 10 20 0.9 l.S Snow 3 IJ600 -6.9 0.20 50 0.9 1. 7 Cloudy 4 4500 -3.3 0.30 IS 0.9 1.8 Cloudy 5 41100 -6.7 0.40 10 0.9 1.8 Cloudy 6 4300 -16.9 0.30 50 0.9 1.8 Sunny ., 4300 -17.8 0.?.0 55 1.0 1.8 sunny 8 4200 -7.5 0.15 55 1.2 1,8 snow 9 4100 -5.6 0.15 55 1.2 2.6 Cloudy 10 4000 -s.o 0.30 50 1.2 2.5 Cloudy 11 11000 -1.1 0.20 50 1.2 2.5 snow 12 3900 -1.9 0.20 35 1.3 3.3 Cloudy 13 3800 -3.1 0.20 35 1.3 3.3 Sunny 111 3800 -1.9 0.20 30 1.5 3.4 Cloudy 15 3700 -12.2 ItO 1. 5 3.11 Sunny 0\ 16 3600 -15.8 60 1.6 3.4 Sunny c.n 17 3600 -15.0 70 1.6 3.4 Sunny I 18 3500 -22.8 0.30 '10 1.6 3.3 Sunny 19 3500 -25.7 0.20 75 1.7 3.3 Sunny 20 31t00 -10.0 0.30 70 1.6 3.3 Snow 21 31a00 -6.4 0.30 60 1.6 4. 1 Snow 22 3300 -5.0 0,110 55 1.6 ''· 1 Sunny 23 3300 -4.4 0.30 45 1.3 4.0 sunny 24 3200 -3.1 0.30 30 1.3 4.0 Sunny 25 3200 -2.8 0.50 40 1.2 3.9 Sunny 26 3100 -3. 1 0.40 50 1.2 3.8 sunny 27 3100 -8.3 0.40 50 1.2 3.8 Sunny 28 3100 -12.8 0.50 60 1.3 3.8 sunny 29 3000 -9.7 0.30 60 1.3 3.8 Snow 30 3000 -8.9 0.20 40 1.3 3.8 Cloudy 1. ~rovlsional data sub,ject to revision by the u.s. Geological Survey, Water Resources Division, Anchorage, Alaska. 2. Average v;o lue of the tlays minimum and maximum temperature. 3. Base.; on one instantanuou~> measurement, usually taken at 9 a.m. daily. 4. Visual estimate based un one instantaneous observation, usually at 9 a.m. daily. I 0\ 0\ ~. -- s5/dd3 TABLE 4.5 SUSITNA RIVER AT GOLD CREEK fREElE•UP OBSERVA Tl ONS ON TilE MAINS l EM December 1982 Gold Creek Mean Air Water Ice in Border Ice Snow D I scha rge ( 1 ) Temperature ( 2) Temperature (3) Channel (If) Thickness Depth Date (QfS) (OC) (OC) !Sl I ftl lliL weather Dec. 1 3000 --1.8 0.10 30 1.3 3.11 Cloudy 2 2900 -16.9 0.10 55 1.3 3.3 Cloudy 3 2900 -16.9 o.oo 70 1.3 3.3 Windy/Sunny 4 2900 -10.0 0.10 1':> 1.3 3.3 Cloudy 5 2800 -8.3 0.20 75 1.3 3.3 Cloudy 6 2800 -1.7 0.20 65 1.3 3.0 sunny 7 28()0 2.5 0.30 40 1.3 3.0 Windy/Cloudy 8 27110 3.6 0.20 15 1.1 3.8 Snow 9 uoo -1.9 0.20 25 1.1 3.9 Cloudy 10 2"/00 -16. 1 0.10 60 1.2 3.9 sunny 11 2MJO -6.1 o.no ItO 1.3 3.9 Sunny 12 2600 -3. 1 o.oo 60 1.3 3.8 Cloudy 13 2600 -1. -, 0. HI 110 1.3 3.8 Sunny 14 2600 -5.0 0.20 25 1.2 3.8 Sunny 15 261l0 -o. 3 0,20 10 1.2 3.8 Sunny 16 2500 -3.3 0.10 10 3.7 Sunny 11 2500 -6.1 0. H) 10 3.7 Sunny 18 2500 -10.6 0.00 50 3.7 Sunny 19 2400 -11.7 o.oo ItO 3. 7· Sunny 20 2400 -7.2 0.00 110 3.7 Sunny 21 2lt00 -21. 1 o.oo 50 0.5 3.7 Sunny 22 21100 -23.1 1),()1) 50 0.5 3. -, Sunny 23 2lt00 -15.6 0.00 30 0.5 3.7 Sunny 24 2400 -11.9 o.oo 30 0.5 3.6 sunny 25 2300 -9.2 0.10 30 0.6 3.6 Sunny 26 2300 -5.6 0.10 30 0.6 3.5 Sunny 21 21100 -1.7 0.10 35 0.6 3.5 Snow 28 2400 0.6 5.0 Snow 29 2600 1.7 0.10 5 overflow 3. 1 Rain 30 2800 -0.3 0.10 25 overflow 3.2 Rain 31 2900 0.10 5 1.3 3.2 Sunny 1. Provisional ..idt.a sub.;oct to revision by the u.s. Geological Survey, Water Resources Division, Anchorage, Alaska. 2. Average va 1 ue or t.he days minimum and maximum Lemperature. 3. Based on one instantaneous measurement usually taken at 9 a.m. daily. 4. Visual estimate based on one instantaneous observation, usuall~ at 9 a.m. daily. r--, I --1 ----, J I 0\ .... I ) L.~ J S~/dd4 TABLE 4.6 SUSITNA RIVER AT GOLD CREEK FREEZE•UP OBSERVATIONS ON THE MAINSTEM January 1983 Gold Creek Mean Air Water Ice in Border Ice snow Discharge ( 1 ) Temperature (21 Temperature ( 31 Channel (II) Thickness Depth Date _lQf..U.._. loCI I oq Iii I ft I 1!.t:J._ weather Jan. 1 2900 -2.8 o.oo 8 1.3 3.2 Sunny 2 2800 -2.8 o.oo 10 1. 3 3.2 Sunny 3 2800 -3.9 o.oo 30 1.3 3.5 Cloudy 4 2700 -5.0 o.oo 60 1.4 3.5 Sunny 5 2700 -13.9 0.10 65 1.3 3.5 Sunny 6 2600 -19. 1 0.10 65 1.3 3.5 Sunny 7 2500 0.00 "10 1.3 3.5 Sunny 8 2500 -25.3 o.oo 65 1, 3 3.3 sunny 9 21100 -22.2 n.oo 60 1.11 3.3 Sunny 10 2400 -20.6 o.oo 70 1.11 3.0 High Winds 11 21100 -16.7 o.oo 85 1 ,If 3.0 Sunny, 12 2300 -18.6 o.oo 90 1.5 3.0 Sunny 13 2300 -16.7 0.00 90 1.5 3.0 Sunny 111 2200 -13. 1 o.oo 100 1.5 3.0 Sunny * 1. Provisional data sub,iec:t t.o revision by the u.s. Geological Survey, Water Resources Division, Anchorage, Alaska, 2. Average value of the tlays minimum and maximum temperat.ure. 3. Based on one instantarmous measurement, uswc lly taken at 9 a.m. daily. 11. Visual estimate based on one instantaneous observation, usually at 9 a.m. daily. * Channel frozen over. I 0\ (X) I s5/jj1 February 4. 1983 Watana Portage Creek Gold Creek curr~ LRX-3 Apri I 12. 1983 Watana Portage Creek Gold Creek Curcy LRX-3 TABLE 4.7 1983 SUSITNA RIVER ICE TlfiCKNESS MEASUREMENTS Mainstem Ice Thicknesses (ft) .Jli!L 1 .II 1.11 1.3 1.8 2.0 1.8 3.0 1.8 1.3 2.0 Max 3.6 3.4 1. 9 2. 1 3.9 11.2 4.0 2.9 3.3 3.8 ~ 2.11 2.5 1.6 1. 9 2.9 2.8 4. 1 2.3 2.2 2.8 Number of Holes 21 5 5 4 5 19 6 6 7 7 Water Surface Elevation 1436.8 834.1 684.6 522.7 342.8 1436.1 833.5 682.9 521.9 341.5 * Average underice water velocit~ was measured at point of most flow and constitutes an average of the vertical velocitY profile. r-. 1'1 '· r-l ,) Average* Under ice Water VelocitY 2.6 2.2 4.2 --, J I 0\ \0 l' l' &5/ffl TABLE 4.8 RIVER STAGES AT FREEZEUP MEASURED FROM TOP OF ICE ALONG BANKS AT SELECTED LOCATIONS Open Water Elevation Maximum Discharge Actual Approximate Top of Ice Corresponding D i scha rge a t River Date of River Bank Elevation* to Stage Gold Creek Mile Location ___ F reezeuJL_ ( ft l (ft. I Ccfsl Ccfsl 148.9 Portage Creek 12/23/82 8113.0 839.5 27,000 2,400 142.3 Slough 21. 119 -/58.3 755.5 140.8 Slough 21, LRX-511 735.3 H3.3 136.6 Gold Creek 1/14/83 687.0 685.3 16,000 2,200 135.3 Slough 11, Mouth 12/6/82 671.5 2,800 130.9 Slough 9. Sher·man 12/1/82 622.4 620.1 30,000 3,000 128.3 Slough 9. Mouth 11/29/82 (6.9) 3,000 127.0 Slough 8, lleac.l 11/22/82 579.3 3,300 12'-1.5 Slough 8, LRX-28 11/20/82 556.2 559.3 44,000 (aufei s) 3,1100 120.7 Curry 11/20/82 527.0 524.6 28,000 3,400 116.7 McKenzie creek 11/18/82 493.3 3,500 113.7 Lane Creek 11/15/82 [6.7) 3,700 106.2 LRX-11 11/9/82 I 5. 3 I 4.100 103.3 LRX-9 11/8/82 384. I 383.9 41,000 4,200 98.5 LRX-3 11/5/82 346.4 345.5 4,400 * Values in brackets I I represent relative elevations based on an assumed datum from a temporary benchmark adjacent to the site. r .· s16/x1 [ l TABLE 4.9 l~ MAJOR ANNUALLY RECURRING OPEN LEADS BETWEEN SUNSHINE RM 83 AND DEVIL CANYON RM 151 r- LOCATION AND SPECIFICATIONS ON MARCH 2, 1983 I location of Velocity Continuous L Upsteam End Channel or Approx. Widest or River Mile # T~~e Thermal length (Ft) Point (Ft) Discontinuous !' 85.0 Main stem Velocity 550 80 Continuous 87.1 Slough Velocity 4,500 50 Discontinuous 87.6 Main stem Velocity 700 100 Continuous l-. 89.0 Main stem Velocity 1,200 100 Continuous Side Channel Velocity 2,500 40 Continuous 89.5 Main stem Velocity 1,400 60 Discontinuous 91.0 Main stem Velocity 1, 700 80 Discontinuous L 92.3 Main stem Velocity 1,300 110 Discontinuous 93.7 Main stem Velocity 3,500 110 Continuous 94.0 Mainstem Thermal 3,500 20 Discontinuous 95.2 Side Channel Velocity 2,400 100 Continuous [ 96.9 Side Channel Velocity 5,600 150 Discontinuous 97.0 Mainstem Velocity 1,100 30 Continuous 102.0 Main stem Velocity 2,400 100 Discontinuous L 102.9 Mainstem Velocity 600 100 Continuous 103.5 Main stem Velocity 1,850 100 Discontinuous 104.1 Main stem Velocity 280 70 Continuous 104.5 Main stem Velocity 1, 700 110 Continuous L 104.9 Main stem Velocity 900 150 Continuous 105.9 Main stem Velocity 1,050 100 Continuous 106.1 Main stem Velocity 200 60 Continuous 106.4 Main stem Velocity 370 50 Continuous L 106.6 Main stem Velocity 350 50 Discontinuous 107.4 Main stem Velocity 200 50 Continuous 109.1 Main stem Velocity 550 100 Discontinuous 110.3 Main stem Velocity 150 100 Discontinuous [ 110.5 Main stem Velocity 290 50 Continuous 110.9 Main stem Velocity 450 50 Discontinuous 111.5 Main stem Velocity 1,600 100 Continuous [ 111.7 Main stem Velocity 500 90 Continuous 111.9 Main stem Velocity 900 150 Continuous 112.5 Mainstem Velocity 700 100 Discontinuous 112.9 Mainstem Velocity 500 110 Continuous L 113.8 Main stem Velocity 600 110 Continuous 117.4 Main stem Thermal 780 60 Continuous 117.9 Side Channel Thermal 1,260 120 Discontinuous 119.6 Side Channel Thermal 550 50 Continuous l : 119.7 Main stem Velocity 350 50 Continuous l -70-l ~ s16/x2 TABLE 4.9 (Continued) Location of Velocity Continuous Upsteam End Channel or Approx. Widest or River Mile# Tl!2e Thermal Length (Ft) Point (Ft) D i sconti n uou s 120.3 Main stem Velocity 800 100 Continuous 121.1 Main stem Velocity 550 100 Continuous 121.8 Side Channel Thermal 1,450 30 Discontinuous 122.4 Slough (7) Thermal 1,850 60 Discontinuous 122.5 Slough (7) Thermal 380 50 Continuous 122.9 Slough (7) Thermal 1,950 80 Discontinuous 123.1 Main stem Velocity 1,000 80 Continuous 123.9 Side Channel Thermal 200 50 Continuous 124.4 Side Channel Velocity 270 40 Continuous 124.9 Main stem Thermal 600 90 Continuous 125.3 Slough (8) Thermal 3,500 50 Discontinuous 125.5 Main stem Velocity 2,140 100 Continuous 125.5 Slough (8) Thermal 800 500 Continuous 125.6 Main stem Velocity 350 60 Continuous 125.9 Slough (8) Thermal 580 50 Continuous 126.1 Slough (8) Thermal 500 30 Continuous 126.3 Slough (8) Thermal 250 50 Continuous 126.8 Slough (8) Thermal 1,500 80 Discontinuous 127.2 Side Channel Thermal 2,450 50 Continuous 127.5 Main stem Velocity 700 80 Continuous 128.9 Slough (9) Thermal 5,060 100 Continuous 128.5 Side Channel Thermal 1,210 30 Discontinuous 128.8 Side Channel Thermal 380 20 Continuous 129.2 Slough Thermal 4,000 30 Discontinuous 130.0 Main stem Velocity 600 90 Continuous 130.8 Side Channel Thermal 5,000 50 Discontinuous 130.7 Main stem Velocity 150 50 Continuous 131.1 Main stem Velocity 490 90 Continuous 131.3 Main stem Velocity 800 100 Continuous 131.5 Side Channel Thermal 5,000 80 Discontinuous 131.3 Side Channel Thermal 900 90 Discontinuous 132.0 Main stem Velocity 150 20 Continuous 132.1 Main stem Velocity 500 20 Discontinuous 132.3 Main stem Velocity 400 80 Continuous 132.6 Main stem Velocity 1,350 80 Continuous 133.i Slough Thermal 6,000 60 Continuous 133.7 Main stem Velocity 1,110 100 Continuous 134.3 Slough (10) Thermal 4,500 40 Continuous 134.0 Side Channel Thermal 1,200 50 Continuous 134.5 Side Channel Thermal 850 100 Continuous 135.2 Main stem Velocity 1,580 90 Discontinuous -71- ~- s16/x3 r- L_ f TABLE 4.9 (Continued) r· Location of Velocity Continuous Upsteam End Channel or Approx. Widest or r , River Mile # T~ee Thermal Length (Ft) Point (Ft) Discontinuous l 135.7 Slough (11) Thermal 51500 80 Continuous f ~ 136.0 Main stem Velocity 230 80 Continuous 136.3 Side Channel Thermal 21050 40 Continuous 136.7 Main stem Thermal 11620 80 Continuous 137.1 Main stem Velocity 750 60 Continuous [ 137.4 Side Channel Thermal 21500 20 Discontinuous 137.8 Slough (16) Thermal 11400 30 Discontinuous 138.2 Main stem Velocity 21000 150 Continuous 138.9 Main stem Thermal 21100 150 Continuous l. 139.0 Main stem Velocity 780 20 Continuous 139.1 Main stem Velocity 500 30 Continuous 138.4 Main stem Velocity 600 30 Continuous L 140.6 Side Channel Thermal 11900 100 Discontinuous Slough (20) Thermal 11100 20 Continuous 142.0 Slough (21) Thermal 31850 40 Discontinuous 141.5 Main stem Velocity 850 40 Continuous [ 142.0 Main stem Velocity 950 50 Continuous 142.6 Main stem Velocity 11600 150 Discontinuous 142.8 Main stem Velocity 850 150 Continuous 143.6 Mainstem Velocity 550 20 Discontinuous r· Main stem Velocity 280 20 Continuous 143.8 Main stem Velocity 780 100 Continuous 143.9 Main stem Velocity 500 30 Continuous 144.5 Main stem Velocity 900 100 Discontinuous L Slough (22) Thermal 250 20 Continuous 144.6 Slough (22) Thermal 300 20 Continuous 145.5 Main stem Velocity 11150 100 Continuous L 146.9 Main stem Velocity 700 100 Continuous 147.1 Main stem Velocity 850 80 Discontinuous 147.7 Mainstem Velocity 150 40 Continuous 148.1 Main stem Velocity 420 50 Discontinuous L 148.5 Main stem Velocity 680 140 Continuous 149.0 Main stem Velocity 400 60 Continuous 149.5 Main stem Velocity 500 80 Continuous 150.0 Main stem Velocity 350 20 Discontinuous [ 150.2 Main stem Velocity 750 100 Continuous 151.2 Main stem Velocity 21800 100 Discontinuous r· L l L -72- L I ...., w I "'I a c: .. • 1-.. 10 -0 0- 0 - w a: ::;) ... -10 c( a: w Q. :i ~ -20- a: -c( > ..J -30 -c( Q z c( w -40 :& l ' j ICE CONCENTRATIONS AT TALKEETNA RELATIVE TO MEAN DAILY AIR TEMPERATURES AT DENALI AND TALKEETNA AND DAILY TOTAL SNOWFALL AT T~LKEETNA - -Ice concentration percentage of channel aurfaca coverage -mean dally air temperature at DenaU (387 freezing degree daye In October) -mean dally air temperature at Talkeetna (170 freezing (Iegree daya n October) 0 total anowfall at Talkeetna (mm) I ... Cit OCTOBER NOVEMBER - z 0 I " ~ I "'I • c .. e t I r---' l -0 ~ 1&.1 u: 10 0 ::) -10 .... cC u: 1&.1 Q. :I 1&.1 .... a: -cC -20 > -30 _. -cC Q z ~ -40 2: ICE CONCENTRATIONS AT GOLD CREEK RELATIVE TO MEAN DAILY AIR TEMPERATURES AT DEVIL CANYON AND DAILY TOTAL SNOWFALL AT GOLD CREEK - -Ice concentration percentage of channel aurface coverage -mean dally air temperature at Devil Canyon 0 total anowfall at Gold Creek (mm) r-. ' ' \ \ I ~\ ~I I I i\ IJ I I ·~\I II \ 1 I I v 'J October 19 -January 17 r--l ; ;---; l ' freeze-up"-.. I I I ( I I ' I I \ J ( v I I I I I I I I I r _...., I j -100 I ~ I Tao~ J I - z 0 -+eo a- 1 : 1 ~ 1&.1 L4o o I ~ -1 0 I ~ T2o - J I I .... Ul I I I! t! i ~ • i I ... ~ :.! § "' <8 -i II> .! • • • II: • • E • II> .,.. 0 .A a • II: -.. • • • .. t -z 0 t: c > 1&1 ;.,j 1&1 800 eoo 400· 200 co ... 8 20 co ... Cll ... .. Q 0 ... ; z -Q 0 1.1 mild .....---7 mild--.. ... ~ z • :r I '0 "' i .. ~ Cll II> 0 z " ' J ... .. ... ... I ., .. = co., ¥ c:a., i .. q A oolld \JIOIITAGI CRUK '-sLOUGH It \.... IHOIAN JUVER a.a •JJd t.a 011/d 'GOLD CREEK "'--IHERUAN 'lo.,.ILOUOHI \.._ILOUGH I \CURRY -II •lid ---·-·· ---TALKEETNA' 40 \ ' 'CHULITHA•IUIITHA CONFLUENCE AA8IGIAUX CREEK---. " UICH C..K ILOUOH KAIHWITNA CREE"' CONFLUENCE \ eo ., IUHIMIHI \ \.MOHr AHA CREEK \. 00011 CREEK ILOUOH 80 RIVER MILE 100 120 140 160 SUSITNA RIVER ICE LEADING EDGE PROGRESSION RATES (mllee/dey) RELATIVE TO THE THALWEG PROFILE FROM RIVER MILE 0 (Cook Inlet) TO RIVER MILE 155 I ..... 0\ I ... 0 c .. • t ~~ !! il ~ ., ~ e ' il i(fj "'& .~ r---i -~ • • := c ,_ I CJ) ..J ..J w ~ z -w CJ c 1- U) a: w !( ~ 3.0 2.0 1.0 \ \ \ \ \ \ \ \ \ \- "\ '-... STAGE FLUCTUATIONS IN GROUND WATER WELL 9-1A (River Mile 129.5) RELATIVE TO MAINSTEM DISCHARGE - -USGS dlachargaa at Gold Creak -water aurfeca elevation In ground water well 8-1A ' \ \ "/"\ ', ' ' ' ' ' end data'""······· ••• ......... , ...... ...._..._'- """--- ,-12,000 I . l 1_10,000 I u; -1 ~ I tn ya.ooo ~ J a: c I z (,) tn -Q J '-..leading edge of lea cover f prograaaea paat well location 0~~----------------~----------------+-----------------+-Lo OCTOBER NOVEMBER DECEMBER MONTH ----' "'I a c .. • t L I u ' J ,j TIME LAPSE CAMERA LOCATION AT DEVIL CANYON • . • MQTTDII.I • ; oWILN.-------<>"~&• { --\V'4Til'llt WIICIC'.C£" I - . --· TDP O' 1~6 AT ~IJC}At~ { --_,,., __ ~6 lt\NI:H tl.l1dl . -.... ~ ~ • ~ 01' It:: I! ~ ~ ~?t..oPt: s8/w1 PHOTO 4.1 Ice plume near Slough 9, flowing towards bottom of photo. Frazil ice can form in September on the upper Susitna River between Denali and Vee Canyon where air temperatures are generally much colder than near Talkeetna. These ice plumes are often the first indicators of frazil formation. PHOTO 4.2 View of the mainstem, adjacent to the town of Talkeetna, on October 12, 1982. Flow is from right to left. Note staff gage in foreground. Water level reads 1.65 feet. llW.Wal·DJM~@ SUSITNA JOINT VENTURE R&M CONSULTANTS, INC. eNOtNa••• oaaa.oa••Ta -·~•• •u•v•YOIIe -78- [ [ c [ s8/w2 PHOTO 4.3 View of the mainstem, adjacent to the town of Talkeetna, on October 30, 1982. The water level dropped over 3 feet since October 12, exposing the gravel bar in the foreground. The photo was taken 5 days before the ice front passed Talkeetna . By November 7, this area was covered by 4 feet of ice. PHOTO 4.4 View of the mainstem, adj~cent to the town of Talkeetna, on November 4, 1982 . The ice front has progressed to within 1 mile of this area, and caused the water level to inr.rease over 2 feet. The shore ice in the foreground has fragmented and will eventually wash away. R&M CONSULTANTS, INC. •NatN•••• o•a&.aat•T• ~AN~IIt• au•vavOtt• SUS/TNA JOINT \lENTURE -79- s8/w3 PHOTO 4.5 Slush ice accumulating by juxtaposition on October 29, 1982 at Sunshine. Flow is frcr,, left to right. This area represents the leading edge of an ice front that has just passed the Parks Highway Bridge. Note the flooded side channel in the upper photo. The ice pack has caused a local increase in water level of about 2 feet. PHOTO 4.6 Shore ice constriction near Slough 9 on October 26, 1982. Flow is from right to left. Note the successive layers of slush ice that have built up along the left bank. Slush ice is being compressed through the surface constriction, emerging on the left as rafts. 11flJ.lm· flj}l~® SUSITNA JOINT VENTURE R&M CCNSULTANTS, INC. •NGtNa••• a•~aa••,.• -...ANfllf•"• su•veva•• -so- [ [ [ c L [ s8/w4 PHOTO 4.7 Shore ice constriction in Devil Canyon on October 21, 1982. Flow is from right to left. Shore ice constricts the surface flow, often concentrating frazil slush into a layer that fragments downstream into pans and rafts. Note the absence of floating ice upstream of the constriction. PHo-.-o 4.8 Ice bridge in Devil Canyon on October 21, 1982. This closure represents the first ice cover on the Susitna above Talkeetna. Flow Is from left to right. The initial constriction by shore ice is still evident. Channel configuration is shallow gradient and gravel bar on the right bank and deep narrow thalweg along the left bank. R&M CONSULTANTS, INC. aNGtN••"• o•a~aat•T• ~ANN••• su•vavCMI• SUS/TN,~ JOINT VENTURE -81- s8/w5 PHOTO 4.9 View of the Chulitna confluence with the Susitna mainstem, looking upstream on October 29, 1982. The Chulitna west channel enters in the left foreground, the east channel comes in on the upper left, and the Susitna River flows diagonally from the center to the right margin. Note the slush ice accumulation at the east channel. PHOTO 4.10 Susitna River confluence with the Chulitna east channel on November 2, 1982, view looking downstream on the Susitna. The slush ice constriction at the confluence has consolidated and frozen, creating this jam and causing subsequent flooding. About 1000 cfs is being diverted into the Chulitna east channel. Compare with photo 11 . IHJMlU1·JEJl1j~~(Q) SUSITNA JOINT VENTURE R&M CONSULTANTS, INC • • NGIN···· a•DLGGia't'• ~ANNe... •u•v•YOII. -82- [ [ [ c [ L s8/w6 PHOTO 4.11 Susitna River confluence with the Chulitna, view looking downstream on November 9, 1982. The Susitna is ice covered and the Chulitna east channel, flowing from right to left, appears as an open lead in the center . The left end of the lead intersects the Susitna ice cover. PHOTO 4.12 The Susitna River at river mile 99.6 looking upstream on November 2, 1982. The river thalweg runs diagonally from the lower right to the upper left of the photo. At river mile 101.3, near Whiskers Creek, about 1,200 cfs was diverted into the side channel on the right. R&M CONSULTANTS, INC • • NDINaa•e G80LDGISTa •LAHNa•a •u•v•vo•• SUSITNA JOINT VENTURE -83- s8/w7 PHOTO 4.13 Susitna River at river mile 106 on November 17 , 1982. Flow is from the upper right to lower left. Ice cover has telescoped to cover the river channel from bank to bank. Note the sagging ice cover over the narrow winter channel and the open leads created by turbulent flow. PHOTO 4.14 Open leads on February 2, 1983 at river mile 103.5, view looking downstream. Note the slush ice cover developing in the foreground. R&M CONSULTANTS, INC. aNOtNaa•• a•aLaaseTa ~ .. ......,..... •u"v•va••• SUSITNA JOINT VENTURE -84- l l [ I [ [ L l s8/w8 PHOTO 4.15 Susitna River at Gold Creek on October 16, 1982, looking downstream from the railroad bridge. Note the frazil slush floes and shore ice development. PHOTO 4.16 Susitna River at Gold Creek on January 13, 1983. Shore ice development has constricted the water surface width to less than 50 feet under the bridge. The ice cover progressed past Gold Creek on January 14. R&M CDN.9ULTANTS, INC. eNGIN···· a•OLDOtSTa ~ANfllll··· su•vava .. SUSITNA JOINT VENTURE -as- s8/w9 PHOTO 4.17 Sample of ice taken during breakup at river mile 142. Dense concentrations of anchor •ice were observed through this reach during freeze-up. This ice had accumula ted sediment by filtration and entrapment of saltating particles. PHOTO 4.18 Extensive shore ice development near the confluence of Devil Creek. Flow is from left to right. Shore ice had built out in successive layers to constrict the channel until slush ice could no longer flow through. R&M CDNSULTANTS, INC • • ....,... • ., aa~ ~ ~~ SUSITNA JOINT VENTURE -86- r [ l s8/w10 PHOTO 4.19 View looking upstream at river mile 104 on February 2, 1983. The ice cover has settled onto the channel bottom except where open leads persist. ~ .,t-;; __ PHOTO 4 :20 Time lapse camera mounted on the south rim of Devil Canyon near the proposed damsite. This camera filmed the ice cover development in the canyon from October 21, 1982 until February 7, 1983. · ~·JEI:Jj~~® SUSITNA JOINT VENTURE R&M CONSULTANTS, INC • • NOtNa••• a•aL.ODt·T· ~L.ANNa•a su•v•vo•• -87- s6/jjl 5.0 SUSITNA RIVER BREAKUP PROCESSES Destruction of a river ice cover progresses from a gradual deterioration of the ice to a dramatic disintegration which is often accompanied by ice jams, flooding, and erosion. The duration of breakup is primarily dependent on the intensity of solar radiation and the amount of rainfall. An ice cover will rapidly break apart at high flows. Ice debris accumulates at flow constrictions and can become grounded. The final phases of breakup are characterized by long open reaches separated by massive ice jams. A large jam releasing upstream will usually carry away the remaining downstream debris leaving the river channel virtually ice free. 5.1 Ice Cover Deterioration Initial phases of ice cover deterioration commonly occur by mid-April. These are identified by flooded snow and overflow on ice and can be attributed to a slight increase in discharge. The rise in water level is generally associated with moderating air temperatures and the increasing daily duration of solar radiation. Solar radiation can cause snow to melt even though air temperatures remain below freezing. Overflow takes place because the rigid and impermeable ice cover fails to respond to water level fluctuations (Table 5.1). Increasing stage results in immediate and severe erosion at the ice/water interface. Where the ice is continuous and unbroken, standing water commonly appears in the sags and depressions. This water substantially reduces the albedo of the ice surface and generally, within days, an open water lead develops in these depressions. With water levels rising steadily, the channel perimeter expands and undercutting of the stranded ice begins. This causes portions of the ice cover to hang over the flowing water of the open lead. When the critical shear stress is exceeded, portions of the ice cover collapse by either hinging at the point where it contacts the bottom or by shearing -88- f - l r r- L [' [ L [ l [_ s6/]j2 vertically from the main ice body. The ice fragments then drift downstream to accumulate with other floes against the solid ice cover at the downstream edge of the lead. By this process, open leads gradually become wider and longer. The high velocity reaches in which most leads form are more common above Talkeetna because the river channel is relatively narrow, lacks a wide flood plain, and has a steeper gradient. Downstream from Talkeetna, the broad and shallow river channel has less gradient and tends to reduce velocities by dissipating the flow over a wider area. Here open leads occur less frequently and the first indicator of rising water levels is exte-nsive overflow. On April 7, 1983 an area of overflow near the Parks Highway Bridge covered the ice sheet with over half a foot of flowing water. The ice cover in this section was a composite of porous slush ice floes that had consolidated during freeze-up and consisted of coarse, rounded ice crystals. Because of its loosely-packed crystal configuration, the ice cover was permeable to water and lacked sufficient buoyancy to break loose from the shore-fast ice and float, so it remained submerged until eventually melting away. Solid and continuous ice covers can fragment en masse when the pressure created by the rising water level can no longer be contained, this was especially on the lower river downstream of Talkeetna. The shattered ice cover, however, will remain in place for several days if the ice downstream remains intact. During April, solar radiation generally increases in intensity and duration. Early in the month, warming air temperatures usually begin to affect the snowpack in the lower elevations near Susitna Station causing it to quickly turn isothermal and melt. By late April, the snowpack has disappeared from the river downstream of Talkeetna and has started to melt in areas along the upper river, especially o.n south facing slopes. The snow laying on the river ice cover is often -89- s6/jj3 relatively thin compared to the snowpack covering the ground because of exposure to higher winds which can rapidly ablate the snow or simply blow it away. In addition, overflow can cause a dramatic reduction of the snow thickness by consolidating and changing the snow crystal structure into ice. On many reaches of the river, the snow cover has been observed to disappear from the river ice while a deep snowpack remains along the banks. Once the snow cover over the river ice melts, solar radiation rapidly disintegrates the crystal structure of the ice. Disintegration of the ice cover by incident solar radiation is commonly indicated by the process of "candling." This phenomena results from a structural failure along the individual crystal boundaries. When ice crystals grow, impurities in the water are expelled from the crystal structure and tend to become concentrated along the crystal edge and at crystal boundaries. Ice crystals generally prefer to grow perpendicular to the c-axis and parallel to the thermal gradient. Simultaneous growth of adjoining crystals prevents much widening and the characteristic long, narrow, six-sided crystals result. The effects of solar radiation are accentuated at the weak crystal boundaries and melting occurs here. This process begins at the ice surface and can extend through the tota! thickness of the ice sheet. Candling significantly weakens the ice which during advanct-d stages of disintegration can shatter on impact into splintered masses of individual crystals. Observations of ice sheet fragmenting during the 1983 breakup on the Susitna River revealed a tremendous resistance by the ice to any form of horizontal shearing. The peculiar resistance to horizontal shear can be explained by the configuration of the crystal structure. The hexagonal crystals fit together in a compact arrangement that eliminates horizontal sliding surfaces between individual crystals. In the vertical direction, however, each crystal boundary represents a sliding surface and every candled crystal will readily shear away from its neighbor. The significance of this phenomenon is evident during -90- r I f - ( ' \ ! [ [ r L I L. ) l - l_ s6/jj4 breakup when tremendous horizontal shear stresses created within massive ice jams often fail to fragment ice sheets at the jam key. However, the stage increases associated with ice jams appear to easily snap loose huge sheets of border ice. On a smaller scale, gradually increasing mainstem discharges continually cause shorefast ice along the flow margins to break away by vertically shearing along ice crystal boundaries. By the end of April, 1983, the Susitna River was laced with long, narrow open leads. Floes that had fragmented from the ice had accumulated into small ice jams. The configuration of these small ice jams often resembled a U or V-shaped wedge, the apex of the wedge corresponding to the highest velocities in the flow distribution. The constant pressure exerted by these wedge-shaped ice jams effectively lengthened and simultaneously widened many open leads. This process of widening the surface area is particularly significant because any ice floes drifting downstream consequently had a clear passage, greatly reducing the potential of ice lodging and creating a major jam. 5.2 Ice Jams Based on historical events and morphologic evidence, several of the small, open lead ice jams were expected to develop into major jams. Examination of mainstem cross sections adjacent to side channels and sloughs indicated a striking similarity of channel configurations at suspected jam keys. Most of the cross sections in these areas consisted of a broad channel with gravel islands or bars and a narrow, deep thalweg, possibly representing an ice scour hole, confined along a rock wall or along one of the banks. The presence of sloughs on a river reach may also indicate the locations of major recurring ice jam events. Many of the sloughs on the Susitna River between Curry and Devil Canyon were carved through terrace plains -91- s6/jj5 by some extreme flooding event. Summer floods, although frequently flowing through sloughs, do not generally result in water levels high enough to overtop the river bank. During breakup, however, ice jams commonly cause rapid, local stage increases that generally continue rising until either the jam releases or the sloughs are flooded. If the sloughs did not exist, then water levels would increase until the capacity of the channel was exceeded and the water would flow laterally out of the mainstem. The flow would probably also carry with it a great volume of ice which could easily erode first the soils and gravels of the terrace plains. Water would continue flooding the overbank until the jam decayed. When no terrace plain adjoins a mainstem ice jam, then stages would increase- to a level that created unstable conditions at the jam key, forcing the jam to release. It seems, therefore, that on the Susitna, sloughs are an indicator of frequent ice jamming on the adjacent mainstem and can also influence the stability and longevity of these jams by relieving the stage increases and subsequent water pressures acting against the ice. In May of 1976 during an extreme ice jam event at river mile 135.9, the river not only flooded the adjacent bypass channel but also carved out what is now identified as Slough 11. Photo 46 is a photograph, taken from the Gold Creek railroad bridge on May 7, 1976, showing a substantial volume of water flowing through Slough 11. The mainstem and bypass channel are towards the right of the photo and appear to be completely ice choked. Local rasidents have indicated that this event created most of Slough 11. Several ice jams of smaller magnitude since 1976 have alst. breached the berm at the channel head and enlarged the slough to its present configuration. -92- r- 1 [ L [ [ [ L r- ~~ r L__ l s6/jj6 The following channels between Devil Canyon and Gold Creek, are regularly influenced by ice induced flooding during breakup: Slough 22 Slough 21 from RM 142.2 to RM 141 Slough 11 from RM 136.5 to RM 134.5 Side channels from RM 133.5 to 131.1 Side channels from RM 130.7 to 129.5 Slough 9 Slough SA and 8 Slough 7 In general, the final destruction of the ice cover is accomplished by a series of ice jams which break in succession and are added to the next jam. This mass of ice continues building as it mc·ves downstream. Upstream from this accumulation, the riv ... ..-channel is commonly ice free except for stranded ice floes and some drifting ice coming from above Devil Canyon. Ice studies during the 1983 Susitna River breakup were oriented towards acquiring ice jam profiles on the river reach between Talkeetna and Devil Canyon as well as quantitative data on ice thicknesses, staging, and flow velocities (Figure 5.1 and Tables 5.1 to 5.4. The specified reach was chosen because of its normally dramatic breakup and potential for massive ice jam formations. Measurements were initially taken twice daily at specific sites known to be affected by ice jams. Water surface elevations, ice thicknesses, and ice cover erosion rates were measured through bore holes. Velocities in the mainstem above and below ice jams were successfully measured by suspending an eltctronic sensor with 30 feet of wire cable from a helicopter and obtaining a spot reading at 2 feet below the water surface. The water depth both above and below jams was also often measured by reading the depth directly from metal flags -93- s6/jj7 attached to the cable which was kept vertical with a 50 lb. lead weight. These data are presented in Table 5. 1. The major streams flowing directly into the lower Susitna River were contributing substantial discharges by April 27, 1983. The ice was in varying stages of decay on these tributaries, with Kashwitna Creek retaining a virtually intact ice cover, and Montana Creek, Sheep Creek, and Willow Creek breaking up rapidly. Observation during an aerial reconnaissance on April 29 documented a rapidly disintegrating mainstem ice cover from Talkeetna down to the Montana Creek confluence. Further d.,wnstream, the· mainstem ice cover was extensively flooded but remained intact. Above the Parks Highway Bridge the ice cover and shattered into large ice sheets in several areas. The large size of these fragments however, prevented the ice from flowing out. At Sunshine, an ice covered reach was flooded by about 1 foot of overflow and yet remained intact. No ice jams had occurred. Observers at Susitna Station reported ice beginning to move downstream on May 2 with flowing ice continuing to pass for several days (Table 5.2). Deshka River residents observed the first ice moving on May 4 and the steady ice flows ending on May 10 (Table 5.3). No significant jams were noted. This indicates an upstream progression of ice breakup which confirmed the aerial observations on the river below Montana Creek. On May 4, 1983, two relatively small ice jams fromed at RM 85.5 and RM 89. The jam keys were small, however even the minimal staging that resulted caused extensive flooding of the surrounding gravel and sand flood plain. Many logs were set adrift appearing to cause damage but most of these logs had previously been stranded by high summer flows. -94- r I r· I l. r L l L r~ L i . [ [ L s6/jj8 The largest ice jam observed on the lower river occurred on MayS near the confluence with Montana Creek at RM 77. Here an extensive accumulation of drifting ice debris had failed to pass around a river bend and jammed. The Montana Creek confluence was flooded but r; j damage or significant impact by ice or w;.:ater was noted. Although the lower river reach had been essentially ice free since May 6, drifting ice released from the upper river was continuing to jam. Residents at Susitna Station, the Deshka River confluence, and Gold Creek provided additional measurements of water levels and ice thicknesses as well as qualitative descriptions of the sequence of events leading up to ice-out. Weekly aerial reconnaissance flights were conducted in order to document the interrelaticnship between river reaches. Tables 5. 1 to 5.4 at the end of this section present all pertinent information. The following description is a chronological sequence of breakup events on the upper river from April 27 to May 10, 1983. On April 27, 1983, daily observations and data acquisition began. By this time, the river had already been opened wide in some areas by the downstream progression of small ice jams. These minor ice floe accumulations remained on the water surface, often breaking down any intact ice cover obstructing their passage. As described earlier, this process is initiated in open leads which gradually become longer and wider until extensive reaches of the channel are essentially ice free. These small ice jams may be important in preventing the occurrence of larger, grounded ice jams. This was evident in 1983 when large ice jams released, sending tremendous volumes of floating ice downstream. The small jams had provided wide passages for the flowing ice which may have jammed again if the channel had remained -95- s6/jj9 constricted. On April 27, extensive channel enlargements and small ice jams were steadily progressing downstream near the following locations: Portage Creek, RM 148.8 Jacklong Creek, RM 145.5 Slough 21, RM 142.0 Gold Creek, RM 135.9 Sherman Creek, RM 131 Curry Creek, RM 120 A large jam had developed near Lane Creek and was apparently grounded. Flooded shore ice surrounding the jam indicated that some water had backed up. A noticeable increase in turbidity occurred on this day. Aerial observations on April 28 revealed an open channel for most of the reach between Talkeetna and Sunshine. Continuing reconnaissance upstream from Talkeetna on May 1 showed that the ice jam at Lane Creek was still accumulating ice floes. The source of the floes was limited to the fragmenting shore ice and no significant accumulation could occur here until ice jams further upstream released. The Lane Creek jam had progressed about 300 feet downstream since April 27. The ice jam near Slough 21 had increased in size and was raising the water level along the upstream edge. This backwater extended approximately 300 feet upstream. Table 15 shows a relative stage increase at this measurement site of over 3 feet in 24 hours. Figure 10 illustrates the water profile before and after this ice jam occurred. By May 2, 1983, several significant ice jams had developed. The small ice jam at Gold Creek had broken through the retaining solid ice sheet forming a continuous open channel from RM 139 near Indian -96- L f' L [ !' L_ s6/jj10 River to a large ice jam at RM 134.5. The small ice. jam that had been fragmenting the solid ice at the downstream end of an open lead adjacent to Slough 21 had progressed down to RM 14nt. A large jam had developed at RM 141.5 leaving an open water a !"lea between the two jams. The upstream ice jam was apparently a:reated when a massive ice sheet snapped loose from shore-fast ice and slowly pivoted out into the mainstem flow, maintaining contact Wlith the channel bottom at the downstream left bank corner. This sheet was approximately 300 feet in diameter and probably between 3 and 4 feet thick. The upstream end continued to pivot around until it contacted the right bank of the mainstem. The ice sheet was then in a very stable position, jammed against the steep right bank and grounded in shallow water along a gravel island on the left bank. Several small ice jams upstream of Slough 21 had released and were accumulating against this ice sheet extending the jam to a total length of about one half mile. The water level had risen and an estimated 2,000 cfs was flowing around the upstream end of the gravel island at RM 142 and into a side channel. The entrance berm to Slough 21 at cross section H9 was also overtopped. This illustrates the extreme staging effects of the jams as the estimated discharge at Gold Creek on this day was less than 6,000 cfs while the normal summer flows required to breach this berm are in excess of 20,000 cfs. The entrance channel at cross section AS was breached and about 150 cfs was diverted into the lower portion of Slough 21. Many ice floes also drifted through this narrow access channel and were grounded in the slough as the flow dissipated over a wider area. -97- s6/jj11 By May 4, 1983, stable ice jams had developed and were gradually building mass at the following locations between Talkeetna and Devil Canyon: Lane Creek at RM 113.2 Curry at RM 120.5 and RM 119.5 Slough 9 at RM 129 Slough 11 at RM 134.5 Slough 21 at RM 141.8 Downstream from the ice jam at Lane Creek, the ice cover was still intact although extensively flooded. Between Lane Creek and Curry, the channel was wide open and ice free with the exception of some remnant shore ice. From Curry upstream to the ice jam adjacent to Slough 7 some portions of the ice cover remained, but were severely decayed and disintegration seemed imminent. An intact ice cover remained from Slough 8 past Slough 9 to the ice jam at Sherman. This ice cover had many open leads and large areas of flooded snow. Between the remaining ice jams at Sherman, Slough 11 and Slough 21, the main stem was open. The jam at Slough 21 was still receiving ice floes from the disintegrating ice cover above Devil Canyon. As ice floes accumulated against the upstream edge of the jam, the floating layer became increasingly unstable. At some critical pressure within this cover, the shear resistance between floes was exceeded, resulting in a chain reaction of collisions that rapidly caused the entire cover to fail. At this point, several hundred feet of ice cover consolidated simultaneously. These consolidation phases occurred frequently during a 4 hour observation period at Slough 21 on May 4. The frequency was dependent on the volume of incoming ice floes. With each consolidation, a surge wave resulted. During one particular consolidation of the entire half mile ice jam, a surge wave broke loose -98- 1- [ .I L_ s6/jj12 all the shore fast ice along the left bank and pushed it onto an adjacent gravel island. These blocks of shore ice were up to 4 feet thick and 30 feet wide. The zone affected was almost 100 feet long and yet the event lasted only a few ·seconds. This process is essentially the same as telescoping during freeze-up except that the ice is in massive rigid blocks as opposed to fine frazil slush and is thus capable of eroding substantial volumes of material in a very short time. The ease with which these ice blocks were shoved over the river bank indicates the tremendous pressures that build within major ice jams. During all of the observed consolidations at Slough 21, the large ice sheet forming the key of the jam never appeared to move or even shift. The surge waves would occasionally overtop the ice sheet, sending smaller ice fragments rushing over the surface of the sheet. Towards the end of the day, the ice sheet was beginning to deform. Incident solar radiation, erosion and shear stresses were rapidly deteriorating this massive ice block and final observations . showed it to have buckled in an undulating wave and fractured in places. Observers at the Gold Creek Bridge reported tremendous volumes of ice flowing downstream at 6 p.m. on May 4 indicating that the jam at Slough 21 had released probably about 1 hour earlier. The ice released at Slough 21 continued downstream unobstructed until contacting the jam adjacent to Slough 11 at river mile 134. 5. The sudden influx of ice displaced the mainstem water and caused rapid staging. Water levels increased sufficiently to breach berms and flood the lower portion of Slough 11 adjacent to mainstem river mile 135. The jam key at this site consisted of _shore-fast ice constricting the mainstem flow to a narrow channel of no more than 50 feet. Large ice floes, mostly from the original jam at Gold Creek, had lodged tightly in this bottleneck. Pressures appeared to be exerted laterally against the shore-fast ice which inherently is -99- s6/jj13 resistant to movement due to the high friction coefficient of the contacting river bed substrate. On May 5, few significant changes were observed in the ice jams despite warm, sunny weather and constantly increasing discharges from the tributaries to the mainstem. It was at first thought that when the ice broke at Slough 11 on May 6, it would carry away the ice jam at Sherman and start a sequence that could destroy the river ice cover potentially as far downriver as Lane Creek. This was prevented by an event that actually increased the stability of the jam at Sherman so that it held for several more days. When the ice jam released near Slough 11 and the debris approached the jam at Sherman, it created a momentary surge of the water level. This surge broke loose huge sheets of shore ice which slowly spun out into the mainstem. One triangular ice sheet about 100 feet wide wedged tightly between two extended sheets of shore-fast ice. Ice floes continuing to accumulate against the upstream edge of this wedge exerted tremendous pressures on the obstruction. A pressure ridge rising at least 10 feet above the ice formed along the contact surfaces of the wedge. This ridge consisted of angular fragments and ice candles. The water level continued to rise as the mainstem channel filled with ice which eventually extended upstream to RM 132.5. The ice jam had lengthened to over 1.5 miles. Flooding quickly occurred on the side channels adjacent to the mainstem and some ice drifted away from the main channel. The volume of water flowing through the side channel was estimated at approximately 2.000 cfs, as the ice jam consolidated and the water level rose, even more water was diverted through the bypass channels. This volume of diverted flow was critical to the stability and duration of the ice jam. Even though the jam increased in size, any additional hydrostatic pressure was -100- ~~ I . ~- r: r· I L [ [ r~ L l. [ r· [ L L L L _j s6/jj14 relieved by diverting water into the side channels. The entire sequence of events lasted only about 10 to 15 minutes. The water level rose over 1 foot during this time span. Consolidations would occur periodically for the rest of the day but the jam key would never be observed to shift. Other jams on May 5 were located at: Slough 9 at RM 129 Slough 7 at RM 122 Curry at RM 120.5 Lane Creek at RM 113 A small jam at RM 126 near Slough 8 consolidated and the resulting surge started a rapid disintegration of the remaining deteriorated ice cover down to the mouth of Slough 8 near Skull Creek. This same surge appeared to have breached the entrance berm to Slough 8. Slough 9 was also flooded by the jam near the head of this channel. The Slough 7 ice jam received some additional floes when the jam at Slough 8 released. This resulted in a gain of ice mass sufficient to cause a rise in water level and flooding at RM 123. At 6:30 p.m. on May 6, a moving ice mass that stretched from RM 136 to RM 138, with lesser concentrations extending for many more miles upstream, was observed approaching the Sherman ice jam, Unfortunately, the consequences of this on the Sherman jam were not observed. The condition of the floes indicated that this ice originated from above Devil Canyon. The well-rounded floes appeared to be no larger than 1 foot in diameter and were presumably shaped by the high number of collisions experienced in the turbulent rapids through Devil Canyon. Reconnaissance of the river above Devil Canyon on May 6 revealed a mainstem entirely clear of an ice cover. Stranded ice floes and fragments littered the river banks up to the s6/jj15 confluence of Fog Creek. In several short reaches from here upstream to Watana, the ice cover remained intact. A large jam had developed near the proposed Watana damsite and extended approximately 1 mile. The entire river from the Watana Creek confluence down to the Parks Highway was reconnoitered on May 7. The following ice jams persisted: Key Location Watana Damsite Sherman, RM 131 . 5 Slough 7, RM 122 Slough GA, RM 112.5 Length 1 mile 3.5 miles 1 mile 2 miles Downstream from the jam at Slough GA, the river retained an intermittent ice cover that was severely decayed and flooded. Below the Chulitna confluence, the mainstem was ice free and no ice jams were o! ,served. The reaches between the remaining ice jams were generally wide open. The Curry jam had released overnight and traveled all the way to the Lane Creek jam. Here, the sudden increase in ice mass shoved the entire ice jam downstream about 1 mile where it again encountered a solid but decayed ice cover. At about 10:30 p.m. on May 8, the ice jam at Sherman released, sending the total 3.5 miles of accumulated ice drifting downstream en masse at approximately 4-5 feet per second. This accumulation of ice, representing many thousands of tons, easily removed the remaining ice jams at Slough 7 and Slough GA. In addition, the last solid ice cover from Slough GA at RM 112 down to the Chulitna and Susitna confluence at RM 98.5 was destroyed and replaced by one long, massive ice jam. This jam extended continuously from RM 99.5 -102- ~~ ! 1 l ' r- L [ L ~~ : L L s6/jj16 to RM 104 and then was interrupted by an open water section up to RM 107. At this point a second ice jam resumed upstream to RM 109.5. This blockage was later measured to be over 16 feet thick in some sections but more commonly was about 13 feet thick. Water seemed to be flowing through the ice jam and in some areas was roiling at the ice surface. These ice jams released on the night of May 9. Further observations were conducted on May 10 between RM 109 and RM 110. Along this reach, the final ice release had left accumulations of ice and debris stranded on the river banks. When the ice jams released, the ice floes piled up along the margins did not move, probably due to strong frictional forces against the boulder strewn shoreline. This created a fracture line parallel to the flow vector where shear stresses were relieved. The main body of the ice jam flowed downstream leaving stranded ice deposits with smooth vertical walls at the edge of water. These shear walls at RM 108.5 were 16 feet high. The extreme height of the water surface within the ice jam was demarcated by a difference in color. A dark brown layer represented the area through which water had flowed and deposited sediment in the ice pack. A white layer near the surface was free of sediment and probably was not inundated by flowing water. On May 10, the only remaining 1ce in the mainstem was on the upper river above Watana. Here an ice jam about 1. 5 miles long had developed near Jay Creek. Ice floes continued to drift downstream for several weeks after the final ice jam at Chase released. As increasing discharges gradually raised the water level, ice floes that had been left stranded by ice jam surge waves were carried away by the current. On May 21, the massive deposits of ice floes, fragments, slush, and debris were still s6/jj17 intact near Whiskers Creek and probably would not be washed away until a high summer flow. The ice breakup of 1983 occurred over a longer time span than in previous years according to historical information and local residents. This is primarily due to the lack of precipitation during the critical period when the ice cover had decayed and could easily and quickly have been destroyed by a sudden, area-wide stage increase. During a year with more precipitation in late April, ice jams of greater magnitude may form and cause substantially more flooding and subsequent damage by erosion and ice scouring. Several important aspects related to ice jams were observed this year and are summarized here: 1. Scour holes are often indicators of ice jam locations. 2. Ice jams generally occur in areas of similar channel configuration, that is, shallow with a narrow confined thalweg channel along one bank. 3. Ice jams commonly occur adjacent to side channels or sloughs. 4. Sloughs act as bypass channels during extreme mainstem stages, often relieving the hydrostatic pressure from ice jams and controlling the water level in the main channel. Ice jam flooding ----·- probably formed the majority of the sloughs between Curry and Gold Creek. --------- 5. Ice jams commonly create surge waves during consolidation which heave ice laterally onto the overbank. -104- r I [ L L r L [ f " L f L r L s6/jj18 6. Large ice sheets ~an break loose from shore-fast ice and wedge across the mainstem channel, creating extremely stable jams that generally only release when the ice decays. -lOS- s5/gg1 TABLE 5.1 WATER STAGE AND RIVER ICE THICKNESS MEASUREMENTS AT SELECTED MAINSTEM LOCATIONS Ice Surface Top of Ice Thickness Elevation 1 Elevation 1 (ft) (ft) (ft) Ae•·il 21, 1983 Gold Creek Discharge: Observed2 = 4300 cfs USGS = 2700 cfs Portage Creek 832.54 Slough 21, LRX-57 -,An L"!!ft t"t;;,.o;;, 755.50 Slough 21, LRX-54 3.06 732.21 733.31 Gold Creek 682.04 Slough 11, Mouth (1.11] [3.30] Slough 9, Sherman 617.18 Slough 9, Mouth 2.16 [5.74] [5.73] Aeril 28, 1983 Gold Creek Discharge: Observed2 = 4100 cfs USGS = 2900 cfs Portage Creek 3.85 834.22 ( +1. 68) 836.96 Slough 21, LRX-57 4.18 753.03 (+3.3) 754.70 ( -0.8) Slough 21, LRX-54 3.00 (-.06) 732.32 (+. 1) 733.28 Gold Creek 681. 94 (-. 1) Slough 11, Mouth [1.26] (+.1) [2.15] (-1.2) Slough 9, Sherman 617.16 620.12 Slough 9, Mouth 2.07 (-.09) [5.57] (-.2) [5.78] Slough 8, Head 5.30 Slough 8, LRX-28 552.39 Curry 3.06 522.46 524.77 McKenzie Creek 487.92 493.33 Lane Creek 2.87 [4.01] [4.81 1 LRX-11 [1.22] [5.30] LRX-9 379.32 383.93 LRX-3 3.68 340.97 342.40 -106 - l [' f l r - I Velocity3 ft/sec l ' r [ ' 5.2 2.1 2.6 4.6 l ' 4.3 1.1 [ l ~ L [ r . L 3.6 r- 3.6 L L { I l ' f r l s5/gg2 TABLE 5.1 (Continued) Ice Surface Top of Ice Thickness Elevation 1 Elevation 1 Velocity3 (ft) (ft) (ft) ft/sec April 29, 1983 Gold Creek Discharge: Observed2 = 4100 cfs USGS = 3100 cfs Portage Creek 2.81 833.04 (-1.18) 834.00 (-2.96) Slough 21, LRX-57 3.85 753.10 754.52 (-.22) 2.4 Slough 21, LRX-54 2.91 (-.09) 732.32 733.25 Gold Creek 681.94 Slough 11, Mouth 1.25 (1.23] [2.53] Slough 9, Sherman 617.29 (+.1) 5.4 Slough 9, Mouth 2.02 [5.80] (+.2) [5.64] (-.06) Slough 8, Head 5.0 Slough 8, LRX-28 552 . 51 ( + . 13) Curry 3.04 522.64 (+.18) 524.77 McKenzie Creek 488.05 (+.13) Lane Creek 2.88 [4.18] (+.17) (4.80] LRX-9 380.63 (+1.31) Talkeetna Airstrip [0.55] April 30, 1983 Gold Creek Discharge: Observed2 = 4325 cfs USGS = 3300 cfs Portage Creek 2.54 (-.30) 833.09 833.85 (-.20) Slough 21, LRX-57 3.95 (•.10) 753.74 (+.64) 754.52 2.8 Slough 21, LRX-54 2.90 731.51 (-.81) 733.15 (-.10) 1.5 __j Gold Creek 682.05 (•. 11) 3.6 Slough 9, Mouth 1.81 (-.20) (5.82] [5.54] (-. 10) Slough 8, Head -5.7 Lane Creek 2.92 [3.90] (-.28) [4.83] 5.3 LRX-11 [ 1. 81] (-.4) LRX-3 3.61 343.43 (+2.46) 342.97 (+.57) -107 - ~~ r s5/gg3 t L TABLE 5.1 (Continued) [' Ice Surface Top of Ice r-- Thickness Elevation 1 Elevation 1 Velocity3 [_ (ft) (ft) (ft) ft/sec May 1, 1983 r ~ Gold Creek Discharge: Observed2 = 4700 cfs ~~ USGS = 3600 cfs Portage Creek 2.11 833.27 (+.2) 833.40 (•.4) Slough 21, LRX-57 3.89 752.54 (-.6) 754. 41 ( -. 1) L Slough 21, LRX-54 2.90 733.09 (+1.6) 733.35 (+.2) Gold Creek 682.20 (+.15) Slough 8, Head 6.5 [ Curry 2.93 (. 1) 523.21 (•.6) 524.64 (-.1) Lane Creek 3.01 [6.85] (+2.95) [6.63] (+1.80) May 2, 1983 [ Gold Creek Discharge: Observed2 = 5750 cfs L USGS = 3900 cfs Portage Creek 2.16 833.63 ( + .36) 833.66 (•.26) L Slough 21, LRX-57 3.90 753.02 ( + .48) 754.45 Slough 21, LRX-54 2.83 731.74 (-1.4) 733.09 (-.24) Gold Creek 682.62 (•.42) Slough 8, Head 8.1 r-Lane Creek 2.92 [6.37] (-.48) [6.50] (-.13) May 3, 1983 L Gold Creek Discharge: Observed2 = 6180 cfs L USGS = 4200 cfs Slough 21, LRX-54 2.81 (-.09) 731.91 (+.17) 733.08 (-.27) Slough 11 , Mouth (4.88] (+3.65) L Slough 8, Head 9.6 ~ : L_ -108- ! s5/gg4 TABLE 5.1 (Continued) Ice Surface Top of Ice Thickness Elevation 1 Elevation 1 Velocity3 (ft) (ft) (ft) ft/sec May 4, 1983 Gold Creek Discharge: Observed2 = 6180 cfs USGS = 4500 cfs Gold Creek 682.78 ( +. 16) Slough 8, Head 9.2 May 5, 1983 Gold Creek Discharge: Observed2 = no data USGS = 4900 cfs Slough 9, H9 berm (breached) 606.51 Slough 9, Sherman 620.89 (+3.60) May 6, 1983 Gold Creek Discharge: Observed2 = 10,920 cfs USGS = 5400 cfs Gold Creek 684.15 (+1.37) -109 - s5/gg5 May 10, 1983 Gold Creek Discharge: Observed2 = 14,350 cfs USGS = 5800 cfs Gold Creek TABLE 5.1 (Continued) Ice Thickness (ft) Surface Elevation 1 (ft) 684.97 (+.82) Top of Ice Elevation 1 (ft) Velocity3 ft/sec 1. Values in brackets [ ] represent relative elevations based on an arbitrary datum from a temporary benchmark adjacent to the site. Values in parenthesis denote the increase (+) or decrease (-) since the previous measurement. 2. Observed discharges were extrapolated from the U.S.G.S. stage/discharge curve and are based on staff gage readings. 3. Velocities represent measurements obtained at one point on a section at a depth of 2 feet. -110 - { f ~ r- r: I r-, l; L L [ L [ L [ [- L [ L [ L L s5/cc3 TABLE 5.2 SUSITNA RIVER AT SUSITNA STATION BREAKUP OBSERVATIONS ON THE MAINSTEM Staff Mean Air Gauge 1 Temperature 2 Ice Thickness Date (ft) (OC) (ft) Weather April 1983 1 4.7 2 4.7 3 0.8 3.3 Cloudy 4 6.18 2.8 3.3 Rain/Snow 5 6.23 3.1 3.3 Snow 6 6.30 3.1 3.3 Snow 7 6.33 3.3 3.3 Cloudy 8 6.33 3.1 3.3 Cloudy 9 6.35 3.6 3.3 Sunny 10 6.35 0.3 3.3 Sunny 11 6.35 0.0 3.3 Sunny 12 6.35 0.6 3.3 Snow 13 6.30 2.5 3.3 Snow 14 6.40 4.7 3.3 Rain 15 6.40 1.9 3.3 Rain 16 6.58 3.6 3.3 Snow 17 6.68 1.9 3.3 Rain 18 6.78 3.3 3.2 Snow 19 6.90 3.6 3.2 Cloudy 20 7.00 3.6 3.1 Cloudy 21 7.10 4.2 2.8 Sunny 22 7.33 6.4 2.6 Cloudy 23 7.63 6.9 2.6 Rain 24 7.95 6.9 2.4 Sunny 25 8.68 10.0 2.3 Sunny 26 9.43 7.5 2.3 Sunny 27 11.10 6.1 2.2 Sunny 28 11.45 3.6 2.1 Cloudy 29 11.00 5.6 2.1 Cloudy 30 11.45 3.6 1.9 Sunny May 1983 1 6.4 Sunny J 2 5.0 Ice began moving Cloudy 3 6.9 Ice flowing Cloudy 4 5.6 Ice flowing Cloudy 5 5.8 Ice flowing Cloudy 6 6.7 Open Sunny 7 8.3 Open Sunny 8 9.4 Open Sunny 9 9.2 Open Sunny 10 9.2 Open Cloudy 11 11.1 Open Cloudy 12 12.5 Open Cloudy 1. Relative elevation based on an arbitrary datum. 2. Average of the maximum and minimum temperatures. -111- r : ' ,~ /eel TABLE 5.3 SUSITNA RIVER AT THE DESHKA RIVER CONFLUENCE r BREAKUP OBSERVATIONS ON THE MAINSTEM Staff Mean Air Snow L Gauge 1 2 Ice Thickne!C;s Depth Temperature Date (ft) (oC) (ft) (ft) Weather April 1983 ~~ 1 0.00 1.4 3.7 Sunny 2 0.00 1.7 Sunny 3 0.00 1.1 Sunny 4 0.00 3.3 Snow [ 5 0.00 1.7 Rain 6 0.00 1.9 Fog 7 0.00 1.1 Sunny 8 0.00 1.7 Cloudy [' 9 0.00 2.2 Cloudy 10 0.00 -1.1 0.10 Sunny 11 0.00 -5.8 0.20 Cloudy [~ 12 0.10 -0.6 1.20 Snow 13 0.10 1.9 0.80 Cloudy 14 0.20 3.1 15 0.40 3.3 r . 16 0.50 4.2 17 0.50 1.7 1.0 Snow 18 0.60 2.8 Cloudy 19 0.70 4.2 Cloudy [ 20 1.00 4.2 Cloudy 21 1.00 4.7 Sunny 22 1.20 6.7 Rain 23 2.00 5.8 L 24 2.40 7.2 Sunny 25 3.40 5.8 Sunny 26 3.40 6.7 Sunny L 27 3.80 6.4 Sunny 28 3.80 3.6 Cloudy 29 3.80 6.1 Rain 30 4.10 6.4 [ May 1983 1 4.30 6.7 2 8.3 L~ 3 7.5 4 7.8 Ice began moving 5 6.9 Ice flowing 6 1.00 6.1 Ice flowing [ 7 1.20 7.8 Ice flowing 8 1.20 9.2 Ice flowing 9 1.20 . 9. 7 Ice flowing l" 10 1.00 8.9 Ice flowing 11 1.00 8.6 Open 12 1.10 10.3 Open 13 1.90 10.6 Open ~ ... 14 1.50 10.3 Open 15 1.50 10.6 Open :"' Relative elevation based on an arbitrary datum. L Average of the daily maximum and minimum temperatures. t -112-L Cl -~ s5/cc2 TABLE 5.4 SUSITNA RIVER AT GOLD CREEK BREAKUP OBSERVATIONS ON THE MAINSTEM Open Staff Mean Air Channel Gauge (1 ) Discharge (2 ) Temperature (3 ) Width (4 ) Date (ft) (cfs) (oC) (ft) Weather April 1983 17 1700 2.8 16 Snowing 18 1800 5.6 16 Partly Sunny 19 1800 6.9 20 Sunny 20 1900 5.8 25 Sunny 21 2000 8.6 40 Sunny 22 2000 8.3 40 Rain 23 2.80 2100 9.7 40 Partly Cloudy 24 2.90 2300 12.5 40 Sunny 25 2400 8.9 40 Sunny 26 2500 8.6 40 Sunny 27 2.57 2700 9.2 50 Sunny 28 2.49 2900 7.5 80 Cloudy 29 2.49 3100 5.0 150 Rain 30 2.65 3300 200 Sunny May 1983 1 2.75 3600 8.1 Open Sunny 2 3.17 3900 8.3 Open Sunny 3 3.30 4200 7.2 Open Rain 4 3.33 4500 8.6 Open Sunny 5 4900 7.2 Open Sunny 6 4.70 5400 Open Sunny 7 5.52 5800 Open Sunny 8 6400 Open Sunny 9 7200 Open Sunny 10 8000 Open Partly Cloudy 11 9000 Open Sunny 1. Relative elevations based on an arbitrary datum. 2. Provisional data subject to revision by the U.S. Geological Survey, Water Resources Division, Anchorage, AK. 3. Average of the daily maximum and minimum temperatures. 4. Visual estimation based on one daily observation. -113 - -.. CD • --z 0 -t- 4( > w _, w I w .... 0 .... 4( ,c. I LL. G: ,. !:) 0 (I) c G: ... • w • t-• ~ 4( • w > -~-t- 4( ... i w ~ "" 0 • ~. ~~ ~ft "'6 :! E .. • .t .. WATER SURFACE PROFILES ALONG 1600 FEET OF RIVER BANK ADJACENT TO SLOUGH 21 BEFORE AND DURING ICE JAM 800 . May 2, Ul83 vertical drop 3.01 feet In 1800 feel channel Ia lea covered ICE JAM May 3, 1883 vertical drop 6.28 feel In 1 800 feel channel 18 Jammed by Ice 800 1200 DISTANCE ALONG RIVER BANK (feet) :------1 l J .....---, J ~, ' I c " 1600'": w ~ ... ~ J :! E .i .. s8/w11 PHOTO 5.1 Ice cover in Devil Canyon at river mile 151 on October 20, 1982. The ice thickness along the shore is about 4 feet and will eventually thicken to over 15 feet. Flow is from lower left to upper right . PHOTO 5.2 View looking upstream at river mile 107 on April 7 , 1983. Water filled depressions in the ice cover, enlargement of open leads, and accumulations of ice fragments on the downstream end of leads are evident and are usually the first indications of breakup. DW.Wl·DM~® SUSITNA JOINT VENTURE R&M CONSULTANTS, INC • • NCIIN.8··· oaOLOG~ -...aNNe-SUIIY.¥0.. -115- s8/w12 PHOTO 5.3 View looking downstream on the upper Susitna River near the confluence of Fog Creek. By April 28, 1983 much of the snow cover had melted, exposing the bare ice to direct incident solar radiation. The \\-"~ter level had increased sufficiently to overflow on the ice cover and widen the channel. PHOTO 5 .4 This moose fell through freeze-up. and became entrapped in the slush ice during JJWlVJ·DU~mJ SUSITNA JOINT VENTURE R&M CONSULTANTS, INC. ............ a•Ot..atat•.-. "LA...._ •u""••....., . -116- [ l l l s8/w13 PHOTO 5.6 The confluence of Deadhorse Creek (at Curry) on April 28, 1983. Flow on the ma instem is from right to left. Open lead on the right is enlarging and fragments of ice are accumulating against the solid ice cover at the downstr'!am end. PHOTO 5.5 This photo shows a : large ice jam at Curry on May 6, 1983. This jam was gradually progressing downstream as the solid ice cover hold i ng back th P. debris slowly disintegrated . JJllMlUl·IEIIJa~® SUSITNA JOINT VENTURE R&M CONSULTANTS, INC. 8NGtN•••• a•aLaat•T• ~~tt..A._.... •u•v••aws -117 .. s8/w14 PHOTO 5.7 When this ice jam adjacent to Slough 21 consolidated on May 4, 1983 it created a surge wave that snapped loose the shore ice and heaved blocks onto a gravel island. The view is looking upstream along the south bank. This ice is about 4 feet thick and the area affected by the surge extended several hundred feet. PHOTO 5.8 This is a close-up view of the ice blocks shoved over the river bank at Slough 21 on May 5, 1983. Note the debris scoured by the ice. IHJilm· !LIM~@ SUS/TNA JOINT VEN1VRE R&M CONSULTANTS, INC • • ,..., ..... _ -Ch..OII••T• --..aNN•-su•v••a.• -118- [ [ [ L L s8/w15 PHOTO 5.9 Gravel and cobble size particles being rafted downstream on ice floes ·near Slough 21 on May 5, 1983. PHOTO 5.10 This shows the key of an ice jam adjacent to Slough 11 releasing. This jam was about . 7 miles long on May 6, 1983 . The pressure exerted on the shore-fast :ce by this accumulation snapped loose these massive ice sheets. lHJMlZI)J· iiM~mJ SUSITNA JOINT VENTURE R&M CONSULTANTS, INC • • HCII,._... GCGLDOI.TS .... ANNa'.. eu•vavDII• -119- s8/w16 PHOTO 5.11 An aerial view of the ice jam near Sherman at river mile 131.5 on May 6, 1983. The flow is from left to right. The original jam had released but the large ice sheets wedged and created this new, and very stable, ice jam that lasted for 2 days. PHOTO 5.12 This is a close-up view of the ice sheet that wedged near Sherman. Massive blocks of ice had fragmented and formed ridges along the shear surfaces. RS.M CONSULTANTS INC. eNo•N••-••a .. aot•TS ~ANNe... .l,•v••a-SUSITNA JOINT VENTURE -120- r L l s8/w11 PHOTO 5.13 The ice sheets holding back the ice jam at Sherman gradually decayed and weakened. They are shown here on May 8, buckled and fractured just before they released. Flow is from right to left . PHOTO 5.14 The ice jam ::~t Sherman accumulated over 1 mile of debris. staging and pressure within the ice pack shoved floes onto the This often knocked trees down and caused ice scouring. The subsequent forested islands. R&M CONSULTANTS, INC. eNa•N•••• .. a ... aa••T• ~•NIIfll•• su•v••at~• SUSITNA JOINT VENTURE -121- s8/w18 PHOTO 5.15 The mainstem channel at Sherman was choked with ice and debris which redirected flow into a side channel adjacent to the mainstem. This island was fl09ded after the jam consolidated and raised the water level about 2 feet on May 8 1~83. PHOTO 5.16 This photo shows the effects of an ice jam near the Susitna confluence at river mile 98 that caused flooding on the adjacent terrace plain, sending ice floes deep into the forest. ~-DM~mJ SUS/TNA JOINT VENTURE R&M CCNSULTANTS1 INC. •Now•eae GeOLCICI••-r. ~ ......... _ .u•ve•OIIe -122- L L s8/w19 PHOTO 5.17 After the ice jam released at Curry on May 7, these ice blocks remained stranded on the gravel bar below Oeadhorse Creek. Some are over 6 feet thick. The large block on the right rests on an extensive layer of solid ice about 0.5 foot thick. PHOTO 5 .18 Poorly ~raded, angular particles shoved up onto an ice sheet at Curry during the ice jam release on May 5, 1983 . IHJJ.lm·IEIBM~® SUS/TNA JOINT VENTURE R&M CONSULTANTS, INC. eHCitfitllaa-OCDLOGtaTII ~ANNIIR. au•v•vCHia -123- s8/w20 PHOTO 5.19 Massive blocks of consolidated slush ice with clear ice lenses. The ice cover, consisting of packed slush ice, is inherently weak and will fracture easily if not supported by water or surrounding ice. PHOTO 5.20 S4:ratigraphy within an ice cover fragment showing alternate layers of packed slush ice and rigid ice lenses. Tape is incremented in tenths of a foot. IJWlU!· liM~@ SIJSITNA JOINT VENTURE R&M CONSULTANTS, INC. aNGtN.81ta -CH..DCIIS~ ltLAfiilffiWe-.UttvaYIMtll r L s8/w21 large ice fragment stranded on a bank after the ice jam at river mile 107 released . The rod is 13 feet high. PHOTO 5.22 The characteristic rippling on the underside of an ice cover. This eros ion feature is caused by the action of waves in turbulent reaches. Dllbll1.lU1· liM~@ SUSITNA JOINT VENTURE R&M CONSULTANTS, INC. •NO •N•••• aaa~oa te'T• .._ .. N ... IIte su•v••OttS -125- s8/w22 PHOTO 5.23 Ice debris piled onto the river bank at river mile 101. 5. The shear wall is approximately 14 feet high. The water level attained during the ice jam is indicated by a line separating the dark layer, with a high sediment concentration, from a lighter and thinner layer on the surface. PHOTO 5.24 View of the shear wall along accumulated ice debris stranded on the riglit bank near river mile 110. Flow is from right to left. This photograph was taken on May 10, 1983 about 8 hours after the ice jam released. The wall is about 16 feet high. lHJU.lUJ·!/lU~mJ .SUSITNA JOINT VENTURE R&.M CONSULTANTS, INC • • Nil,,...... o•aa.oa••~ ~ANIIIMIIttl euiiV••o-• -126- I • [ l L l s8/w23 PHOTO 5.25 After the ice jam released near Chase, the ice severely scoured the river banks and carried away large trees. PHOTO 5.26 This photo was taken on May 7, 1976 from the Gold Creek Bridge, looking downstream towards Slough 11 . The mainstem is completely ice choked and much flow has been diverted to the left into Slough II. R&M CONSULTANTS, INC. 8NO•N•••• a•a~oootaTa ~,.,........ •u•vav011• SIJSITNA JOINT VENTURE -121- s16/u1 6.0 SEDIMENT TRANSPORT The transportation of sediments decreases substantially between freeze-up and breakup primarily because of the elimination of glacial sediment input. The glaciers contribute the majority of the suspended sediment by volume to the Susitna. Other factors that significantly influence the sediment regime are turbulence, velocity, and discharge, all of which are greatly reduced during the winter. The advent of frazil ice in October, however, greatly increases the complexity of sediment transport by providing a variety of processes by which particles, both in suspension and saltation, can be moved. Ice nucleation, suspended sediment filtration, and entrainment of larger particles in anchor ice are some of the processes described in this section. The dramatic nature of breakup often introduces sediment to the flow by re-entraining particles that had settled to the bottom. This ice event is characteristically accompanied by ice scouring and erosion during extreme stages. Ice jam induced flooding commonly flushes sediments from side channels and sloughs. Ice blocks are heaved onto river banks or scraped against unconsolidated depositional sediments, removing soils which may become entrained in the turbulent flow and carried downstream. Laboratory investigations have determined that ice readily nucleates around supercooled particles. These particles may be in the form of organic detritus, soils, or even water droplets (Osterkamp, 1978). The Susitna River prior to freeze-up abounds in clay size sediment particles which may form the nucleus of frazil ice crystals. The first occurrence of frazil is generally also marked by a reduction in turbidity. Visual observations seem to indicate that the decrease in turbidity is proportional to the increase in frazil ice discharge. The Susitna has often been observed to clear up overnight during heavy slush flows. It is not certain whether this occurs because of the nucleation process or by filtration. As described in previous sections, frazil ice crystals tend to flocculate into clusters and adhere together as well as to other objects. When frazil -128- r~ I f ' [ L L [ [ [ r , L" [ [ L s16/u2 floccules agglomerate they form loosely packed slush (Newbury, 1978). Water is able to pass through this slush but suspended sediments are filtered out. Sediment particles are therefore entrained in the accumulating ice pack. Ice shavings from bore holes drilled through the ice often contain silt-size particles of sediment. Early flows of slush ice accumulate on the lower river below Susitna Station and progressively advance upstream. These early slush floes possibly filter high sediment concentrations in October and retain them in suspension all winter. When frazil ice collects on rocks lying on the channel bottom, it is referred to as anchor ice (Michel, 1971). Anchor ice is usually a temporary feature, commonly forming at night when air temperatures are coldest, and releasing during the day. Like slush ice, anchor ice is porous and often has if dark brown color from high sediment concentrations. These sediment particles were either once suspended and subsequently filtered out of the water or else were transported by saltation until they adhered on contact with the frazil. When anchor ice breaks loose from the bottom, it generally lacks the structural competence to float any particles larger than gravel-size. Clusters of released anchor ice, suspended in the ice pack and clear border ice, have been observed near Gold Creek. Frazil slush is therefore an effective medium for sediment transport during freeze-up whether the process is nucleation, filtration or entrapment. An ice cover advancing upstream can cause a local rise in water levels, often flooding previously dry side channels and sloughs. Substantial volumes of slush ice may accompany this flooding. On December 15, 1982, Sloughs 8 and SA were flooded when the ice pack increased in thickness on the mainstem immediately adjacent to the slough entrance. These sloughs received a disproportionate volume of slush ice relative to water volume since the water breaching the berm constituted only the very top layer of mainstem flow. The majority of slush ice floats near the water surface despite only minimal buoyancy. The flow spilling over the slough berms therefore carried a high concentration of ice. This slush ice and -129- s16/u3 entrained sediment rapidly accumulated into an ice cover that progressed up the entire length of Slough SA. Side channels and sloughs that were breached during freeze-up and filled with slush ice are not necessarily flooded during breakup. If these sloughs are not inundated then the ice cover begins to deteriorate in place. The entrained sediment consolidates in a layer on the ice surface and effectively reduces the albedo, further increasing the melt rate. What finally remains is a layer of fine silt up to i inch thick covering the channel bottom and shoreline. If berms are breached during breakup, then ice fragments from the main channel are washed into the slough and usually become stranded when flows dissipate. These ice floes then simply melt in situ, depositing their sediment load in the side channel. This occurred in May 1983 when the "A5" access channel to Slough 21 flooded during a major mainstem ice jam. Shore-fast ice along the perimeter of an ice jam is usually not floating. When debris accumulating behind a jam consolidates, the resulting surge wave may provide the critical lifting force to suddently shift the bc-rder ice. This occurred near Slough 21 on May 4, 1983. Tons of ice were shoved onto a gravel island entraining particles up to boulder-size and producing ridges of cobbles, gravels and organics. By this process of laterally shoving substrate material, ice can build up or destroy considerable berms and decrease the size of gravel bars near ice jam locations. When the lateral pressure exerted by ice is complicated by simultaneous downstream movement such as during an ice jam release, the effects on the river banks can be devastating. Many cubic feet of bank material was scoured away in minutes when massive jams released near Slough 21, Sherman, and Chase in ~ay 1983. An interesting phenomenon observed during breakup was the effective filtering capability of ice jams and individual ice blocks. Sediment-ladened water flows through the many channels and interstices between the -130- l ) [ r L [' [ L L [ s16/u4 fragments in an ice jam. These interstices are usually filled with porous slush which removes suspended sediments from the water. Ice jams can concentrate sediment in this manner and often become very dark in color. As discussed, Susitna River ice generally consists of alternating layers of rigid, impermeable clear ice and porous, loosely packed, rounded crystals of metamorphosed frazil ice. Water can percolate through the permeable layers which strain out suspended sediment particles. This sediment becomes concentrated when the ice melts and is either re-entrained into suspension or deposited on the river bank if the ice floes were stranded. -131- s16/z 7.0 ENVIRONMENTAL EFFECTS This section briefly discusses the significant aspects of river ice relative to channel morphology, aquatic and terrestrial habitats, and vegetation. Ice obs~r-1:1~~.io11s in the thalweg result in hydraulic SC()Uriflg, flow diversions and ~l~di~g ___ ~f. isoJ~ted sloughs. Ice floes shifting during --~------------------~. freeze-up and the transportation of ice blocks by breakup floods can remove bank and bed material and create vegetation trim lines. On ___ the upper Susitna River between the Chulitna confluence and Devil Canyon, --~----~------·----·--------------··-----·---------~----· there are reache~. especially prone to annual ice daf!:!~!!~. ~hi I~ the _r-iv~r below Talkeetna _r:arel~~perien~.a~.--~raJI~.~t.!C._ iC.~ ___ _=yf;lnts. This can be attributed to contrasting river morphology, the upper river is narrow and steep and the lower river is generally broad and shallow. 7. 1 Susitna River Below the Chulitna River Confluence This section of river is characterized by a broad, multichannel configuration with distances between vegetated banks often exceeding 1 mile. The thalweg is represented by a relatively deep meandering channel that usually occupies less than 20 percent of the total bank to bank width. At low winter flows, therefore, the thalweg is bordered by an expanse of sand and gravel. The variation in average monthly discharges are extreme for total flows below Talkeetna, normally ranging from about 3,000 cfs in March at Sunshine to over 60,000 cfs during the summer, with peak flows being much higher. The stage fluctuations corresponding to these discharges are usually not severe because the broad channel has a high flow capacity. Ice cover progression frequently increases --~--------- the stage about 1-2 feet above normal October water levels. No -·----------------------· --------~-----~-------------·-· -~------------ significant flooding takes place, for even at these stages the flow ~ ~---------~-____ .. ___ .. ___ _ usually remains well within the channel boundaries. The lower river -------:-----···-·-----·-·-------·----·- ice cover is therefore often confined to the thalweg and surface -132- ,. r· ,. L . [ [ [ [ [ L [ [ L L. s16/z profiles do not approach the vegetation trim line along the banks. -. . --· -·-· ~~ ---------- The existing trim lines are indicators of peak summer flows rather than ice scour. --- Tributaries to the lower river seldom enter the mainstem directly. Willow, Kashwitna, and Sheep Creeks first flow into side channels and are rarely affected by stage increases due to ice cover progression. Montana Creek however, feeds the thalweg channel and on October 28, 1982 the confluence was flooded by about 1 foot of slush ice which subsequently froze. This ice cover had little effect on the tributary flow regime since the streamflow quickly opened· a channel through the slush. Rabideux Slough was flooded with saturated slush on October 29. The ice cover had reached the Parks Highway Bridge and caused water levels to rise about 2 feet. This was sufficient to overtop the berms normally isolating the slough. The staged water had expanded out of the thalweg channel and reached both banks at the bridge. Portions of Birch Creek Slough, Sunshine Slough, Rabideux Slough and Goose Creek Slough, were also inundated by slush and formed an ice cover. Groundwater seeping into these channels, however, prevented a continuous cover from remaining all winter. Breakup ice jams have occurred near the conflu.enc.e_Q[ Montana Creek ·------·--------. ~· ·-·· -····------·------~---- an9 also ~t river miles 85.5 and 89. Extensive areas of gravel and '• • • '< o • -~ .. ·-•-• ··----V-,__,_ ..__, __ sand Ylere fl~de~ .. ~1"1-__ !9~ ---~espite minim!!_ _ __!!~S!!--J~.~!:.~!I~S. ~ _!!lajority of the_ inundated side channels were affected . only by water and no erosion ~r s~urfngby ice blocks was cibse~-~d.----·- This section below the confluence r~ula_rly_ exper.ie!'lce~ J~xteo.~ive flooding during summer storms. These seem to have significantly . -····. .. ·-.. ---------0· ··--.-. -~-"'"' --~ ---··--· . ---~ ............. ,. more effect on the riverine environment than processes associated . ······-----··'--~ -·--··--·--------··------·-·· ----~-------~---~---------~- with ice cover formation . -133- s16/z 7.2 Susitna River Above the Chulitna River Confluence / I / The effects of river ice between the Chulitna confluence at RM 98 and Portage Creek at RM 149 are evident by the ice scars on trees, the scoured sloughs and side channels, and the drumlin shaped islands. Under normal winter conditions, the ice is actively affecti·ng channel 1 ;orph~~~gy~--~~~e~!~-~?n, terrestrial and aquatic habitats, and / groundw_~ter __ l~y__!_l~. This reach_ .:~~~~ b~ _!_~V!_r"_~~~ _!!!'pacted by ice regime modifications ind_y_c;_e.d_ b:y-i-ncr-eased wtnter discharges from -·---------------------. hydroelectric dam projects at Devil Canyon and Watana. Slush ice ca~ o_~~_!r~ct th~ __ !19\!_ in th~Lmaio_~_n_d. c!i_~e!"t wate~-~nd ice into side channels. This has been observed annually on the river -·----·-------~--- rl.JCh between Whiskers Creek and the Chulitna confluence. The shallow, multichannel area between Slough 8 and 9 also frequently has flows redirected by slush ice obstructions. These flow diversions during freeze-up however, do not cause much erosion or vegetation ------damage. ------------- Ice obstructions during breakup in the mainstem can divert large ---·-----------------. --~----------·~ ----------------·---..... volumes of ice into side channels. If the subsequent erosion is -·•*•••4•·•-•-••'"•• • •••-. ------··•·•• ~··· ~· ·-• _., severe and the side channel bottom is lowered, then the mainstem flow ..... --~-----..---------·· -·--···»' --------------------····· -~----"-----,....--··-······-------------~--.. ---- could permanently shift. This shift in flow from one bank to the other will tend to eni-;.rge the river boundaries. This r-rocess is evident in an early stage at RM 130.6 and more advanced at RM 112.7. Scour holes occur where an ice cover or ice jam has created a conduit, directing flow against the bottom. Velocities through these confined channels cause great hydraulic forces which can scour the bed material to considerable depths. Scour holes may therefore be good indicators of frequently recurring ice jam locations. A typical cross section at a scour hole consists of a shallow gravel bar on one bank tapering to a deep and narrow thalweg along a vertical outcrop. -134- { ! ' -~ i r - l ' [ - [ L [ [ [ [ L [ [ s16/z Depth soundings at these cliffs sometimes indicate holes in excess of 25 feet (R&M, 1981a). Cross section surveys have identified scour holes at the following locations: RM 135.9 along the right bank, RM 131.4 along the left bank, and RM 128.5, RM 126.5, and RM 120.5 along the right bank (See Appendix B). These sites correspond to frequently recurring ice jam locations. ~--and extren:!_~ _s_~~ging at major ice jams occurs d~ri~g J~r_ea~.up_.__ /, Water levels generally continue to rise unttr"either the jam releases or the water leaves the channel, inundating sloughs and flooding islands. On May 5, 1983 near Sherman at RM 133, a jam caused extensive flooding that flowed over the forested islands adjacent to the mainstem. These flood stages persisted for over 48 h<>urs, leaving a deposit of sediment on the forest floor. The long-term effects of these short duration floods are not known, however, burrowing, nesting, and spawning habitats must certainly be impacted. The frequency of major ice jam events is often indicated by the age or condition of vegetation on the upstream end of islands in the mainstem. Islands that are annually subjected to large jams usually show a stand of ice scarred mature trees ending abruptly at a steep and often undercut bank. A stand of young trees occupying the upstream end of islands probably represents second generation growth after a major ice jam event destroyed the original vegetation. Denuded gravel bars may be advanced ice scour features. Vegetation is prevented from re-establishing by ice jams that completely override these islands. Ice jams do not consistently occur every year at the same locations. --------. -----~---~-· Their magnlfiide and ·c:onditions controlling formation are usually unpredictable. Areas where jams occur frequ~ntly are evident by numerous side channels and sloughs. Major ice events probably ~o~~-ed ~he_~o~~when ice floes surmounted the river banks._ ~e ~ I fv ,/ C.,.., ? ~ (-o' '/ .J . •·"'<" / " -..._ • /J · /" V -135- s16/z / J size and configuration of .... ~xisting sloughs i~--_depe~-~!l'l_t on . the -frequency of ice jamming in the adjacent __ mainst«!!'!.-Susitna River sloughs are usually flooded at high summer discharges when berms normally isolating these side channels are breached. These berms usually cons is~_ o_f unconsolidated particles larger than the hydraulic competence of the overtopping flow and therefore summer erosion is often limited. Ice floes, however, weighing many hundred pounds can easily move the bed material, substantially lowering the entrance berms and the slough bottom. This was observed at Slough 21 in May, 1983. A surge wave overtopped a shallow gravel bar that isolated a side channel. The surge also created enough lifting force to shift large ice floes. These floes barely floated but were carried into the side channel by the onrush of water, dragging against the bottom fo1· several hundred feet, dislodging cobbles, and scouring troughs in the bed material. This same process will also enlarge the sloughs. When staging is extreme in the mainstem and a large volume of water spills over the berms, then ice floes drift into the side channel scouring the banks and moving bed material, thus expanding the slough perimeter. This scouring action by ice can therefore drastically alter the aquatic habitat. Summer flows that periodically breach the sloughs are usually of low velocities and generally do little to modify the channel, however, they may -cause transport of silt and sand within the channel. By examination of the valley geomorphology, river morphology, and ---,_, ___ _ ice processes-, -If seems·· tnat islands, gravel bars, river banks, and ·----------.. ·~·~--"' -~----- the thalweg are features more controlled by ice scouring and --~~--~----·-~' ---~----· overriding than by annual summer floods. These floods often approach the vegetation trim line along the bank, but many denuded gravel bars remain exposed even during the annual flood:--- Based on observations from 1981 to 1983, it seems that ice jams have significant effects on riverine habitats. As previously described, these effects can best be studied from Slough 21 downstream to -136- 1 \ l .,- r·' l r· [ [ [ [ [ [ L I L s16/z Chulitna confluence. A major jam has formed annually for the last 3 years from the Chulitna confluence (RM 90) to Chase (RM 108). The jam height of more than 15 feet was more than sufficient to override all the gravel bars in the area and severely scour forested islands. When this jam broke and the ice moved downstream along both sides of many mainstem islands, many feet of unconsolidated bank material were removed. The islands between RM 107 and RM 100 (see Appendix B) show the characteristic drumlin shape of mainstem river ice erosion. The morphologic evidence indicates that this reach above ------------------------ the Chulitna confluence co~,ald be affected by accelerated ice erosion if ----· ---· -._. '~ -~---· --·' -···-··-------"--·-----------~ major jams were to occur more frequently due to hydroelectric dam operations. -137- s16/y1 8.0 REFERENCES Alaska Department of Fish & Game. 1982. Susitna Hydro Aquatic Studies Phase II Basic Data Report. Anchorage, Alaska. 5 vol. Ashton, George D. 1978. River Ice. Annual Reviews on Fluid Mechanics. Vol. 10. · pp. 369-392. Benson, Carl S. 1973. A Study of the Freezing Cycle in an Alaskan Stream. Fairbanks, Alaska. Institute of Water Resources. 25 pp. Bilello, Michael A. 1980. A Winter Environmental Data Survey of the Drainage Basin of the Upper Susitna River, Alaska. Special Report 80-19, U.S. Army Corps of Engineers, Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire. 1 vol. Calkins, Darryl J. 1978. Physical Measurements of River Ice Jams. Water Resources Research, Vol. 14, No. 4 (August). pp. 693-695 . . 1979. Accelerated Ice Growth in Rivers. U.S. Army Corps of Engineers, Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire. 5 pp. Edinger, J.E., et. al. 1974. Heat Exchange and Transport in the Environment. Baltimore Maryland. John Hopkins University. 124 pp. Michel, Bernard. 1971. Winter Regime of Rivers and Lakes. U.S. Army Corps of Engineers, Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire. 130 pp. Newbury, Robert W. 1968. The Nelson River: A Study of Subarctic River Processes. University Microfilms, Inc., Ann Arbor, Michigan. 319 pp. -138- r , l. I : f ' [ [ [ [ r L L s16/y2 Osterkamp, Tom E. 1978. Frazil Ice Formation: A Review. Journal of the Hydraulics Division. Proceedings of the American Society of Civil Engineers. September, pp. 1239-1255. R&M Consultants, Inc. 1981a. Hydrographic Surveys Closeout Report. Anchorage, Alaska. Alaska Power Authority. Susitna Hydroelectric Project. Report for Acres American, Inc. 1 vol. 1981b. Ice Observations 1980-1981, Anchorage, Alaska. Alaska Power Authority. Susitna Hydroelectric Project. Report for Acres American, Inc. 1 vol. 1981c. Preliminary Channel Geometry, Velocity and Water Level Data for the Susitna River at Devil Canyon. Anchorage, Alaska. Alaska Power Authority Susitna Hydroelectric Project. Report for Acres American, Inc. 1 vol. 1982a. Field Data Collection and Processing. Anchorage, Alaska. Alaska Power Authority. Susitna Hydroelectric Project. Report for Acres American, Inc. 3 vol. 1982b. Hydraulic and Ice Studies. Anchorage, Alaska. Alaska Power Authority. Susitna Hydroelectric Project. Report for Acres American, Inc. 1 vol. 1982c. Hydrographic Surveys Report. Anchorage, Alaska. Alaska Power Authority. Susitna Hydroelectric Project. Report for Acres American, Inc. 1 vol. 1982d. Ice Observations 1981-82. Anchorage, Alaska. Alaska Power Authority. Susitna Hydroelectric Project. Report for Acres American, Inc. 1 vol. -139- s16/y3 1982e. Processed September 1982. Anchorage, Climatic Alaska. Data, October 1981 to Susitna Hydroelectric Project. 8 vol. Report Alaska Power Authority. for Acres American, Inc. 1982f. River Morphology. Anchorage, Alaska. Alaska Power Authority. Susitna Hydroelectric Project. Report for Acres American, Inc. 1 vol. 1982g. Slough Hydrology. Anchorage, Alaska. Alaska Power Authority. Susitna Hydroelectric Project. Report for Acres American, Inc. 1 vol. Smith, D.G. 1979. Effects of Channel Enlargement by River Ice Processes on Bankfull Discharge in Alberta, Canada. Water Resources Research, Vol. 15, No. 2 (April). pp. 469-475. U.S. Geological Survey. 1982. Water Resources Data, Alaska, Water Year 1981. Anchorage, Alaska. Water Resources Division, U.S. Geological Survey. United States Department of the Interior. -140- [ [ [ L [ [ [ L s16/y4 APPENDIX A Monthly Meteorological Summaries for Weather Stations at Denali, Watana, Devil Canyon, Sherman and Talkeetna __ .; -141- R & M CONSULTANTS~ :1: NC. ~:; l.J ~3 :1: T N A H Y X> I~ 0 E:: 1. •• 1::: c; T I~ :1: C t=" I~ 0 .. T 1::: C T MONTHLY SUMM~RY FOR DENALI WE~THER STATION DATA TAKEN DURING DeceMber, 1982 ( RES. !!AX. I!IH. KEAN IIIMD Df'Y T£!IP • T£1111 • T£!11, UIR. !lE& C DEG C DE& C DE& RES. AVG. !!AX. IIIND IIItlD &UST SPD. SPD. DIR. 1!/S 1!/S . DEC MAX. GUST P ''JAL taN ltEAN SPD. DIR. RH DP PRECIP !!IS % DEG C till DAY'S SOLAR OOC'f DAY WH/SQlt ·----------------------~~~J--------------------------------·---------------------- 2 3 4 5 & ' 8 9 to t1 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 'l1 28 29 30 31 I!QHTH l!IIIH Hfll -'l/.2 -24.3 -15.4 -4.4 2.7 .~ -1.0 -18.6 -9.8 -7.6 -3.4 -5.5 -5.2 -12.9 -7.8 IHH HIH UHf IIIII IHH !IHI IHH UHf HHI HHf IHH UHf lHIHf l!HH !HII H!lf!f -35.4 -32.8 -28.1 -:!1.9 -? ., ... -5.0 -28.7 -:!7.4 -~.9 -12.~ -11.9 -16.8 -16.3 -17.7 -15.'3 IHH I!Hf IH!II 1!0! Hl!l Hill H!IH !!HI! IHH HIH IHH !!I!! II UHI Ul!!l 2.7 -35.4 GUST GUST GUST GUST l!IHI HI ~;Hit -31.3 HI -28.2 1!1 -21.8 Ill -13.2 IH -2.5 m -2.2 !1!1!1 -11.9 I!H -23.0 !Ill -17.:! !IH -te.t !1!1!1 -7.2 Ill -tt,2 II! -18,8 IH -15.3 1!11 -tt,6 IH Hili. 1!11 ~ I!H !!i{ii!\ Ill!! . ''· *!~~ !Ill !If!~ HI l!IHI l!H ~~ !Ill HiD IH tix)·j **' .. ~ '·., HHI !lt!J! .. -.J.._a 1HH H!! Mi\ HI -to,·; JI!IH H!l ~ !*! -14·,4 IH 1!1!1 HH IH!I 11!!1 **** HH HI! H!l **** HH Ill! f!!l!f 1!1!1 Hf! **** !!H !!H! HH H!!l 11!1 !II! H!* l!HI ee IH!! UH HII IHf II!H! ll!l! 1!!!11 !!1!!1 VEL. AT MAX. VEL. AT MAX. VEL. AT MAX. VEL. AT MAX. Hit HH .... !!HI !!HI H!l I !!II! !11!1 1111 HH HH IH!I !!IH IIH !IH l!tH I!! II! HH !Ill! !I HI Jl!l!! !1!1!1 l!ll!l IIH I!!H HH IHI 1!!1!1 l!lf!!l *!!f!f lflll! **** GUST GUST GUST GUST !!H !I!! IH !II!! !!II !!H HI !Iff IH !!I!! !!I!! *** HI !1!1 IH 1!11 HI !II! HI *** Ill !!I!! Ill 1!!1 Ill !Ill Ill Ill I! I! !!!II lfl!! !If! Ill! Ill HI! 1!1 lll!l IH 11!!1 !II! !Ill 11!1 IHf !!Ill !!!1!!1 l!lll !HI HI 1!!1!! Ill IHI !IH Hll ll!!l !!Ill !!II I!Hll l!H HH HI HH Ill !!ll!l !!1!1 IIH !!I! 1!11!1 IH 1111 ll!l !11!1!1 1!1 !!!H 1!1 1!!1!! 11!!1 Hll HI Hit H!! filii HI !11!!1 ll!f HH HI !!lilt !1!11 1!!11 Ul !!!f!f Iff! lll!l!ll fl!ll I!IH !!II H HH! !!!f l!l!!l!! lfl li!HI II!! l!!lf!ll 1!1 111!1 !I !!11!!1!! I!! l!IHI II!! !!1!!1! Ill HH! I!! !IHI!I H IIH! H 1!1!!1!1 *I HH! H f!IIH H 1111! I! 1!!11!1 H IHH H !!I!!H Ill !!IHl! !!I lfH!!I !!! llll!H !I. !1!!1! l!ll H!!!l H !1!!1 1!1 IHII I! 1!!1!1 II !H!I !I !!1!!1! 1!1 l!!l!f n "'**** !fl l!liUI !II :tHI!! lUI IH! !1111 !!!!1!1 !!!Ill I 1!!1!! U!!l HI Iff !11!!!!1!! 4&Z 460 Jt5 379 Jta 1 5 6 ., , !1!1 3'3~ s IHI 128 9 H!fl 379 19 IIlii 265 11 1!11 :55 12 1!11 301 1:! HI! 30'3 1~ II!H 318 15 1!!11 299 t~ IIlii 241 17 l!!!!f !11!111 19 1!!!1 HIHI 19 !!!lf!! l!!!l!!l!! 2~ 111*1 ' H*UI 21 l!!l! ~1!!!1!!!! 22 *IH H!ff!tl 23 IHlf !l!!!!l!f 2#. IIlii 11*!!111 25 !!!!!!!! !!ll!lll!l 2& IIH !11!11 27 H!l !!lUI!! :!8 ***~ 411!!!11 29 ~f!ll !l!!!!l! 30 U!H~ ll!lfHI 31 ll!!l!! 511.:! MINUS 2 MINUS 1 PLUS PLUS INTER 1J~LS INTERt.JAL 1 INTEf~1.J:-"\L 2 INTEP.'v1taLS 999.0 999.0 999.0 999.0 NOTE: REL~TIVE HUMIDITY RE~DINGS ARE UNRELI~BLE WHEN WIND SPEEDS ~RE L~SS TH~N ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOR REL~TIVE HUMIDITY ~ND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** ··142- MONTHLi 'SUMMA~Y FOR DENHLI ~EAT~ER STATION DATA TAKEN DURING Janua~y~ 1983 NOiE: MAX. ilAY iEl'.P. ~Eli!: itltt. T£itil. ilE& \. ----------- 1 ..... 2 ***** 3 UIO 4 QIIH 5 lltUI b HlH 7 Uttt 8 tlflll 9 UIU 10 "**** 11 ..... 12 -25.9 13 -28.3 14 -17.C. 15 -14.7 1& -8.3 17 -7.6 18 -5.8 19 -c..; 20 -8.2 21 -12.& 22 -17.3 2.3 -16.5 24 -8.6 25 -13.5 2.6 -9.5 21 -e.l 28 -5.8 2.9 -12.8 30 -8.0 31 -b.5 ltOtiTH -).l' ..... IIIII ..... litH IIIIHt ..... IIIII Hllf Htltlt IIIII 1811 -32.8 -3&.0 -32.9 -24.4 -18.2 -14.8 -14.4 -13.& -19.1 -23.3 -24.7 -27.5 -20.i -2.4.-\ -2.1.o -19.4 -14.2 -22.6 -23.1 -t3.o -36.ii GUST GUST GUST GUST iiES. liEAtt WIND TEJIP, DIR. DE& t llEG -~·-:-:~~ .. , .::. ~'l-Ill **"'·· •fi;! *-*1~ ~·3*1.\ ~~~ '-~!~-..... • 4 (o.-..... -29.4 -32.2 -(5.3 -19.11 -13.3 -tt.Z -10.1 -10.2 -13.7 -1a.a -21.0 -22.8 -14.3 -19.1 -15.6 -13.9 -18.1 -17.8 -15.6 -10.f -17.1 *** llif ltlt Ill Ill Ill ... 1111 ... tH Ill Ill ... till Ill tllli Ill hit *** Ill ... lit ... iES. lilND SPD. iliS mt !Ill-A~ 1111 .... lUI .... .... IIIli .... 1111 .... I Iff 1111 .... 1111 1111 .... lllf 1111 .... tlllt IHI nu lfll .... IIH ltlllt IHI Ultl 110 atU tUt VEL. VEL. VEL. VEL. AT AT AT AT MAX. MAX. MAX. MAX. ;WG. WIND 5Pii. :i/S lUI Ult1t Hit lift lUI fill lilt IIIII IIIII lfll IIU IIH IIH **** .... Hll !till liHit IIH Hf·l Uti .... uu lllll ltiH **** .... IHI nu I til .... HH ht\iL GUST iili. DE& IU Ill Ul Ill ... '** Ill Ill Ill ... HI *" Ill Ill ... HI IH *** Iff ... llllt ... ltU ... HI IH Ill ... *** Ill Ult A41 i'IAX. bUST P'\1111.. i'IEAif SPD. DIR. RH iliS % hEAti DP DEG C PREC~P nn ili\I'S SOLAR C:fi£iii't DRY liltJSQit --------------- no 111 .,, itU tH II Uti lltl II fHI ill II IIIli llil II lUI ... • • .... lllt tl 1111 ... •• Jttll ••• ltl IIIII IH ill .... ... lit 011 Ill 77 lUI Ill 75 '"* *** eo 1111 IH lit IIH HI II ltltltl Ul II 1111 *** .. ma 111 n • ... Ill •• llltl Ill lit illl IH tf Jllll lilt» 83 1111 HI 59 ....... 71 IHI IH 83 ltlllt Ill If 11-il Ill II UH lilt H .... Ill •• Ult lll ttl **** Ill 74 ..... •••• 111111 1 ..... 1111 ...... 2 IIUt ttu uun 3 , •• ~. fill ****** 4 lf<ttl ~lhU ..... . ... HUt ltl1tf IHH HH 1111111 tHt ..... 1111 IIIH IHI -32.4 .... -35.1 .... -32.5 IHI ..... *"* lUll lUI Htll lltll- 1-1111 1111 IUIIt JtHI ..... Hll flttltl *"* ......... -24.4 ltH·lt -21.9 IIH -24.7 .... -1&,9 HH HHf Hll ..... 1111 lllltll "** ·UIII IIH ltlllltl ltHI -2b.S **** Uttft 5 ...... 6 Ullltt 7 l***** a Ulttl!t Y Ulltt 10 ...... 11 tllftl 12 ...... 13 ...... 14 1111111 15 ...... 16 Hltllt 17 HUll 19 lltllt 19 ****** 20 lttiHt 2! ****" 22 Ulttlt 23 ****** 24 Ulllt 25 ...... 2.b ...... 27 1111!11 28 ~UIH 29 nun ;;c A·liH'It 3l lltilliU GUST MINUS GUST Mii'liUS GUST PLUS GUST PLUS 2. INTERVALS 1 INTERW-iL 1 INTEi~VAL 2 INTERVALS 999.0 999.0 999.0 999.0 RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ONE METER PE~ SECOND. S0CH READINGS HAVE NOT BEEN I~CLUDED OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. ARE LESS THAN Ir~ THE DAii...Y SEE NOTES AT 7HE BAC~ OF THIS REPORT **** -143..; r· l [ [ L [ [ L [ L I L R & M CONSULTANTS~ ZNC. SUSZTNA HYDROELECTRZC PROJECT MONTHLY SUMMARY FOR DENALI WEATHER STATION DATA TAKEN DURING February, 1983 1£5. 1£5, A\'G. JIM. MX. MY'S MI. IWI. lUI 1118 u. -liUST liUST P'VI. ItEM ti£M SlUR MY TEIIP. .... TEMP. ID, SPI. SPI. ID. SPI. ID. RH -IP PI£ClP EIBCY lAY 16t Bt Bt 16 IllS IllS 16 NS 1 DSC lit Ill/Sill t .7 -14.2 ..... ... HH HH ... HH ... H HHt HH ..... 1 2 -4.2 -u.a .... ... HH HH ... HH ... H IHH HH IHIH 2 3 -3.7 -11.1 -7.4 ... HH HH ... .... ... H IHH HH 241 3 4 -4.6 -ll.9 -1.3 ... HH HH ... HH ... H IHH HH 698 4 5 -4.4 -14.2 -9.3 ... HH HH ... .... ... H IHH H .. 813 5 6 -3,6 -11.6 -7.6 ... HH HH ... HH ... H IHH HH 74J 6 7 -3.2 -8.1 -5.7 ... HH HH ... HH ... H IHH HH 851 1 8 -5.3 -9.9 -7.6 ... HH HH ... HH ... H HIH HH 518 a 9 -9,2 -14.1 -tt.6 ... HH HH ... HH ... H IHH IHI 771 9 tl -11.9 -22.4 -17.2 ... HH HH ... HH ... H IHH HH 873 11 11 -13.7 -24.9 -19.3 ... .... HH ... HH IH H HIH HH 1371 11 12 -15.7 -26.8 -21.3 ... HH ·HH ... HH ... H HIH HH 948 12 13 -22.8 -31.1 -26.4 ... .... HH HI HH IH H HIH HH 15!1 13 14 -19.2 -31.6 -25.4 IH HH HH IH HH HI H HIH .... 1758 14 15 -16.7 -31.2 -24.1 ... HH HH ... HH ... H . .... IHI 1775 15 16 -17 .• 5 -31.4 -24.5 HI HH HH ... IIH IH H HIH HH 1845 16 17 -17.6 -31.4 -24.5 IH HH HH ... .... ... H IHH HH 1895 17 18 -14.5 -31.1 -22.8 HI HH HH HI HH IH H HIH HH 1221 18 19 -4.9 -19.1 -12.1 ... HH HH ... .... IH H HIH HH 1995 19 21 -8.3 -19.1 -13.7 ... HH .... HI HH ... H HIH HH 1663 21 21 -5.5 -···· -1z.1 IH HH HH IH HH IH H IHH HH 1981 21 22 -5.1 -18.1 -11.6 ... HH HH IH HH IH H HIH HH 2131 22 23 -8,9 -22.1 -15.5 IH HH HH HI HH IH H IHH HH 197$ 23 24 -3.3 -12.5 -7.9 IH HH HH HI HH IH H HIH HH 1298 24 25 -8.3 -17.6 -13.1 IH HH IIH HI HH IH H HIH HH 2181 25 26 -6.6 -15.8 -11.2 ... ..... HH HI HH ... H HIH HH 2171 26 'D -8.4 -17.2 -12.8 HI HH HH ... HH ... H ..... HH llill 'D 28 -3,8 -11.4 -7.1 tH 1.1 1.1 tH 1.1 tH '* tfiH HH 1318 28 ltlllllll • 7 -31.6 -···· ... 1.1 ••• ... 1.1 ... H HIH HH 36413 _;; GUST VEL. AT HAX. GUST MINUS 2 INTERVALS 999.0 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 999.0 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 999.0 GUST VEL. AT HAX. GUST PLUS 2 INTERVALS 999,0 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY _oJ OR MONTHLY HEAN FOR RELATIVE HUHIDITY AND DEW POINT, **** SEE NOTES AT THE BACK OF THIS REPORT **** 144- l~ ·~ J!x M (::(:lN~:~lJI ... TANT~:~ > :1: N C • f ' ~=~ l.J ~a :1: T N A H Y "() I~ (:J E:: 1-1::: (:: T I~ :1: €:: P I~ (:l .. T 1::: (:: T [' MONTHLY SUMMARY FOR DENALI WEATHER STATION ~~ DATA TAKEN DURING March~ 1983 RES. RES. tWC. 111\X, 111\X, DAY'S ~~ 111\X, IIIN. II£AII IUD Ylltl 111111 GUST GUST pI 11M. ItEAM IIEAN SOUl DAY TEitP. TEitP. TEIIP. IIR. SPD, SPI. DU. SPJ, DU. RH DP PIECIP EIIIGY DAY IIEG C DEG C IIEGC IIEG IllS IllS B IllS z BC Ill 111/SDit ,-, 1 -7.7 -18.4 -13.1 IH HH HH IH HH HI H HtH Hll 1321 1 l ' 2 -u.s -23.2 -17.4 IH HH HH IH .... IH H HtH HH 1515 2 3 -12.6 -26.2 -19.4 IH HH HH IH HH IH H HtH IHI 983 3 \ 4 -12.5 -19.7 -16.1 IH .... HH IH .... IH H HHI IIH 1313 4 5 -11.1 -21.1 -15.1 IH HH HH IH HH IH H HtH .... lt78 5 6 -11.1 -20.6 -15.4 IH HH .... IH .... IH H HHI HH 1865 6 7 -9.4 -21.9 -15.2 IH HH HH IH HH IH H HIH HH 2158 1 [ 8 -tt.7 -26.4 -19.1 IH HH .... IH .... IH H HtH .... 2333 8 9 -11.7 -26.7 -18.7 IH HH HH IH IHI IH H HHI HH 3129 9 ll -8.8 -14.3 -11.6 341 1.5 1.7 'l!fl 7.1 NNII H HIH HH 2185 II 11 -1.7 -13.4 -7.6 174 2.4 3.3 166 8.9 SSE H HIH HH 2113 11 [ 12 1.8 -12.5 -5.4 126 .1 1.6 165 9.5 .. H HtH .... 2318 12 13 -.8 -16.2 -8.5 338 .7 1.2 m 3.8-H HIH IHI 3193 13 14 -4.2 -17.1 -11.7 336 .4 .9 344 3.2 1111 H HIH HH 2891 14 [ 15 -.9 -15.0 -8.1 172 .5 1.7 165 5.7 s H HIH .... 2573 15 16 -3.1 -10.6 -6.8 347 1.8 2.1 341 5.7 1111 H HtH HH 3133 16 . 17 -5.1 -16.1 -11.6 341 1.1 1.4 336 3.8 18111 H HtH .... 3611 17 18 -4.9 -21.6 -13.3 342 .8 1.3 351 3.8 liNII H HIH HH 3331 18 L. 19 -6.4 -19.7 -13.1 335 .6 1.1 331 3.8 • H HtH IHI 3388 19 21 -3.4 -16.4 -9.9 244 .I 1.5 161 7.6 N H HIH HH 328S 21 21 -.9 -15.1 -8.1 341 .7 1.1 186 3.8 N H HIH IH1 3578 21 22 -3.3--16.6 -11.1 344 .6 1.1 116 2.5 .... H HIH HH 3713 22 [ 23 -4.7 -18.D -11.4 341 .a 1.1 335 3.2 Ntll H HIH Hll 3855 23 24 -3.9 -19.8 -tt.9 343 .7 1.1 114 3.2 .. H HIH HH 3178 24 25 .1 -14.3 -7.1 346 .9 1.3 39 4.4 • H HtH IHI 3923 25 26 -3.7 -17.1 -11.4 171 2.2 3.1 176 11.8 s H IHH HH 3868 26 [ 27 -3.6 -15.9 -9.8 175 1.6 3.2 172 12.7 s H HIH IHI 3933 27 28 -6.3 -17.8 -12.1 348 1.3 1.7 127 5.7 1111 •• IHH HH -28 29 -1.6 -28.1 -11.8 341 .a 1.3 344 3.8 HMII H HIH IHI 4258 29 [ 31 -2.1 -17.8 -11.1 345 .7 1.1 341 3.2 .. H HIH HH 4333 38 31 -1.8 -16.9 -9.4 348 1.6 1.a 218 5.1 IIIII H IHH HH 3871 31 ltOiffif 1.8 -26.7 -u.s 335 .4 1.6 172 12.7 111111 •• HIH HH 91588 GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 9.5 [ GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 9.5 GUST v.::L. AT MAX. GUST PLUS 1 INTERVAL 11.4 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 11.4 L AR.E LESS THAN NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND S~EEDS ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY [ : OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND OEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** l~ -145-. l R & M CONSULTANTS> INC. SUSITNA HYDROELECTRIC PROJECT MONTHLY SUMMARY fOR DENALI WEATHER STATION DATA TAKEN DURING April~ 1983 RES. RES. AVG. 111\X, ttAX. DAY'S MX. IWI. IIENI YDII MID 111111 GUST GUST P'YM. tiEAII IIEAII SOLAR DAY TEIIP. TEitP. lEJtP. Dll. SPD. SPD. DII. SPD. DII. RH DP PRECIP EHERGY DAY BC BC DEl: C 1I£G K/S K/S DEl: ti/S I D£G c !Itt Ill/Sill 1 -1.1 -16.8 -9.1 341 1.6 1.9 342 ,,7 IIIII H ..... ••• 4385 l 2 -.7 -1&.5 -8.6 339 1.2 1.6 344 5.1 till H ..... ••• 4683 2 3 3.8 -14.5 -5.4 151 2.9 3.8 138 23.5 s H ..... 1.8 4735 3 4 4.5 -4.4 .1 195 2.1 4.1 154 28.3 IISII H ..... 1.1 2441 4 5 .a -8.8 -4.1 166 4.1 4.5 152 13.3 SSE H ..... o.8 4165 5 it 1.3 -ll.9 -4.8 186 .4 t.lt 184 7.8 s H ..... 8.1 5848 6 7 .8 -13.9 -&.6 335 .a 1.4 811 5.1 IIIII H HHI O.D 4655 7 8 .a -16.9 -8.1 341 1.8 1.5 34ft 3.8 IIIII H ..... D.l 4871 8 1 9 2.7 -11.7 -4.5 339 .& 1.4 225 5.1 IIIII H HHI 1.8 4&15 9 11 -&.7 -18.& -12.7 Ill 3.4 3.5 816 &.3 N •• Htlt 0.1 5410 11 11 -4.2 -22.2 -13.2 188 1.5 3.2 141 16.5 Sll H IIHI 0.1 3783 11 ! 12 4.3 -5.0 -.4 168 3.1 3.8 14ft 15.2 SSE H IIHI D.l 4235 12 13 -.6 -9.9 -5.3 344 1.3 1.8 335 5.1 Hilt .. HHI a.o 3398 13 14 1.9 -2.9 -.5 191 4.1 5.1 171 12.7 s H IHH .2 5&91 14 - 15 2.1 -3.8 -.5 1&1 3.9 4.3 155 12.7 SSE H ..... .2 4031 15 \ l6 .t ·4.2 -2.1 351 4.0 3.1 339 7.6 1111 H ttHI ••• 5368 16 17 4.6 -8.2 ·1.8 241 .2 2.6 161 11.4 NNE H ..... 8.0 5551 17 18 2.4 ·4.1 -.9 152 4.8 5.4 137 17.8 SSE H ..... 8.1 5628 18 I 19 3.1 -2.2 ·' 152 6.1 6.5 144 21.3 SE H IIHI o.o 5918 19 20 5.7 -4.1 .8 176 2.2 3.1 162 14.1 s H IIHI ••• 5115 21 21 4.2 -5.1 -.1 181 .9 1.& 159 7.& s H ..... D.l &193 21 J 22 5.1 -4.2 .4 181 3.3 3.5 167 u.8 s H ..... D.l 6341 22 23 5.4 -1.8 1.8 191 1.7 2.1 188 7.6 s H IHH 1.1 5171 23 24 5.7 -2.4 1.7 34ft 2.1 2.5 339 8.9 Nlll H ttHI a.o &921 24 'l 2S 12.5 -2.5 5.0 329 .7 1.7 1&6 5.7 II H ..... ••• 68115 25 26 &.4 -3.5 1.5 348 2.8 2.9 116 &.3 1111 H ..... 8.8 &m 2ft ?:1 &.5 -3.3 t.& 359 2.7 2.8 119 5.7 II H ..... 8.0 6865 ?:1 28 7.8 -4.7 1.& 326 .6 1.2 336 4.4 NW H ..... 1.0 5155 28 J 29 5.4 .2 2.8 358 2.2 2.3 351 6.3 II H ..... .4 4115 29 "' 31 4.4 -2.8 .a 353 3.8 3.9 339 8.9 II H IHII 0.1 7128 3D IIONTH 12.5 -22.2 -2.3 166 .4 2.9 138 23,5-H ..... .a 154391 ] GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 20.3 ~ GUST VEL. AT i1AX. GUST MINUS 1 INTERVAL 19.7 GUST VEL. AT MML GUST PLUS 1 INTERVAL 19.7 ., GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 17.1 I NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN 11 ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT, **** SEE NOTES AT THE BACK OF THIS REPORT **** H -146-il t r - r-~ I ·~ t!x M CONSUt .. TANTB ... :t: NC • r - Bl.J$ :1: TNA HYX)I~ Ol:::t..I!!:CTI~ :J: C p 1~ o .:.r 1::: c T MONTHLY SUMMARY FOR DF.:NALI WF.ATHER STATJON L DATA TAKEN DURING May, 1983 RES. RES. AVG. !tAX. I!AX. DAY'S r~ ltAX, KIN. ~AN !liND lUND !liND GUST GUST P 'IJAl HEAH liE AN Sll.A,. DAY TEfiP. mtP. Tall'. IIR. SPD. SPD. IJR, SPD, DJR. RH DP PRECIP ENERGY DAY [ DEG C DEG C OEG C DE& "'s "'s DEC "'s '% DEG C !ill WH/smt 1 6.1 -5.2 .5 211 t.l 1.1 183 8.3 SSII H IIHf ... lsi'~ 1 2 5.0 -.8 2.1 218 .s 1.7 138 9.5 II H HIH t.2 3541 2 ~-: 3 Hf!ll liHI HIH HI HH IHI IH .... IH H IHH ***' HHH 3 4 3.8 -4.5 -.4 229 .4 t.1 110 4.4 sw .. HIH 0.8 5198 4 5 5.5 -3.0 1.3 334 .8 1.6 343 5.7 HHII H IHH ••• 7188 5 [ 6 6.5 -2.4 2.1 331 .s 1.2 321 3.8 H H HIH O.D ssoo 6 7 6.8 -1.3 1.8 348 2.5 ~.8 342 7.0 tiiW lfl IIHI 0.1 1,803 1 8 8.8 -1.7 3.6 346 1.3 1.5 l4tl 4.4 11!11 II HIH o.a 7510 e 9 9,8 -2.8 3.5 229 .6 1.3 205 4.4 Sll H IHH 8.0 6715 9 L to 9.2 -1.6 3.8 213 1.6 2.7 177 '1.6 s H HHI ••• 1553 tO tt 10.2 -2.5 3.9 312 1.1 2.2 262 b.J NHII H fHH ••• 7473 !t 12 7.4 .3 3.9 203 1.2 1.8 181 8.3 ssw .. HIH o.o 4561 12 13 11.3 1.0 6.2 195 1.2 1.5 228 5.7 ssw H IHH ... 5983 13 [ 14 9,8 2.5 6.2 198 1.4 2.2 187 7.1 s II fiHf e.o 5313 14 15 13.7 1.8 6.3 324 t.O 1.9 171 5.7 NMI ** fHff 8.1 6318 15 16 8.4 1.8 4.7 182 2.4 2.9 175 11.4 s H HIH 2.8 t.~ 16 [ 17 5.9 .4 3.2 21!1 .5 t .4 264 7,0 ssw ** fHff t.8 3221 17 18 5.7 t.2 3.5 170 .3 1.6 159 7.0 II H fHH 8.0 3905 lll 19 ~.0 -1.6 '3.1 321 ,., 1.6 264 6.3 N H IHH 3.0 5898 19 28 11.1 3.3 7.2 283 2.8 3.5 233 9.5 • If HIH e.o 5383 20 [ 21 8.5 t.!l 5.2 263 2.4 3.0 263 10.8 IISV •• IIIII 0.1 4138 2t 22 9.7 2.2 5.5 186 1.5 2.0 164 8.3 SSE H HIH .3 4?83 22 23 8.5 .6 4.6 143 1.8 2.5 143 12.7 SE H fHH 1.6 4135 23 24 9.6 1.1 5.4 946 .4 2.5 ttl' 9.9 HNII H HIH B.l 5893 2.t [ 25 13.1 • 1 6,6 343 .1 2.4 298 7.6 N .. fHff ••• 6(23 ~5 26 7.7 2.4 5.1 185 .a 1.9 223 9.5 s II HIH ., 3785 26 ... ?:1 9.6 0.8 4.8 297 .6 ~.1 148 1.6 IIIII II IHH 9.1 4883 27 L 28 13.9 ::.4 8.7 081 .4 1.9 122 tt .4 E H "*** o.o 4000 28 29 16. t 5.0 10.6 145 3.5 4.0 160 17.1 ~ '* ***" Q.t -MJI 29 30 21.4 7.7 14.6 177 1.2 2.4 177 1i.4 s If ltiHf o.o 5753 JO 31 15.8 .q 9.? 164 3.1 4.2 138 17.1 SSE ill **"* 9.8 4843 31 [ MONTH 21.4 -5.2 4.9 208 .5 2.2 160 17.1 "NV .. fHH 1.b 160899 GUST \)f.:l. • AT MAX. GUST MINUS 2 JNTFPUAJ .. S 10.2 GUST VF.:L. AT MA~. GUST MINUS 1 INTERVAL 10.8 [, GUST tJEL. AT MAX. GUST PLUS 1. INTF.R~JAL 11.4 GUST IJF.:L. AT MAX. GUST PLUS 2 INTERVALS 7.6 NOTE: RELATIVE HUMJDTTY READINGS ARE UNRFLIAaLE WHEN WTND SPFFDS ARE: L.FRS TI-IAN f . ONF.: METER PF.:R SF.:COND. SUCH READINGS HAVE NOT BEEN INCLUDE:l> IN THE DAILY OR MONTHLY t1EAN FOR REL..ATJVF HUMJDJTY AND DF~ POJNT. ·lf*•lf* SEE NOTES AT THF.: BACK OF THIS REPORT ~*** l." -147- f ~ R & M CONSULTANTS, INC. ~:; U ~:; :1: T N A 1-1 Y l) I~ l:l r::: L t::: l:; T I~ :1: C P' I~ C) .:r 1::: C T MONTHLY SUMMARY FOR WATANA WEATHER STATION DATA TAKEN DURING SepteMber~ 1982 RES. RES. .we. !tAX. ltAX. DAY'S ltAX. !WI. lUI IIIB lllNI lllND GUST GUST P'Wl IIEMI ION SOLAR DAY TEltP. TEll'. TEJII. D11. SPD. SPD. D11. SPD. Dll. RH DP PIEClP EKERGY Dt\Y rsc DE&C DESC DEC IllS ft/S DEG "'' % DE& c lilt IIH/51111 1 11.1 2.6 6.9 158 .7 1.4 145 5.1 N H ..... .2 3498 1 2 tt.3 1.2 6.3 251 .7 1.9 247 7.1 E H HIH 2.2 3938 2 3 7.1 2.1 4.6 J37 .4 1.1 251 5.7 N H ..... 8.2 2098 J 4 11.5 .1 5.6 159 . a 1.6 138 4.4 N H HIH 8.1 4485 4 5 13.6 2.9 8.3 119 5.6 5.& 194 14.1 E H ..... .8 2191 5 6 14.5 5.9 11.2 818 2.8 3.5 182 11.2 E H HIH 1.2 2938 , 7 9.9 5.1 7.5 269 2.8 2.9 254 7.1 II H HID 4.4 2865 7 8 7.4 4.9 6.2 266 1.6 1.8 211 4.4 · II H HIH 2.2 1491 a 9 8.8 4.6 &.7 189 1.7 2.1 887 8.3 E H IHH 4.& 2265 9 11 8.5 3.4 6.1 851 1.2 1.5 167 4.4 II H HIH u 2221 II 11 6.6 .6 3.6 257 1.1 1.9 255 8.9 II H ..... 12.1 1695 11 12 7.6 -.It 3.5 181 2.4 2.8 176 11.8 E H HIH 2.6 3743 12 13 12.1 1.4 6.8 l6l 2.3 3.7 ISS 8.9 EM£ H IHH 18.6 2195 13 14 7.8 5.2 6.5 179 1.7 2.1 113 7.1 EM£ H HIH 12.6 1185 14 15 9.1 &.It 7.9 154 3.5 3.6 169 7.6 ME H HIH 7.6 542 15 16 11tH 11tH 11tH HI .... HH tH IIH HI II HIH IIH HIHI 1ft 17 7.9 6.1 7.1 29fa 1.1 1.3 331 3.2 1111 H ..... 1.1 918 17 18 11.4 6.1 8.7 118 2.1 3.2 111 8.9 E II ..... ... 2315 18 l9 8.1 2.11 5.4 269 1.1 1.5 251 5.7 II H ..... 4.8 1·HI 19 21 7.3 2.4 4.9 353 .1 1.3 2l8 4.4 II II IHH ,6 2145 21 21 11.2 2.1 6.2 179 2.4 3.9 188 11.4 E H HHI t.lt 1413 21 22 6.5 -1.1 2.7 286 1.2 1.9 248 7.6 II H IHH t.l 2728 22 23 6.7 -4.1 1.3 325 .8 1.7 226 5.1 II H HtH ••• 3958 23 24 7.9 -5.6 1.2 113 2.2 2.3 115 7.1 E H 11tH ••• 2961 24 25 11.2 -1.1 4.6 DSB 1.4 1.9 178 7.1 E H HtH I.D 2745 25 26 5.2 .9 3.1 326 .6 1.5 145 5.1 1111 II ltHI 2.8 1798 26 21 6.3 -2.1 2.2 28S 1.6 2.2 269 7.1 II H IIHI .6 2755 21 28 3.1 -4.3 -.6 176 4.3 4.4 183 9.5 EJIE H HIH 2.1 1591 28 29 4.7 ,I 2.4 171 2.8 3.1 192 7.6 liE H Hill s.a 1131 ~ 31 2.9 -1.1 .9 214 ·' 1.1 261 3.8 II H HIH 4.4 1568 31 IQfTit 14.5 -5.6 5.1 162 ,9 2.4 194 14.1 E H IHH 111.8 67241 GUST VEL. AT MAX. GUST t1INUS 2 INTERVALS 10.8 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 9.5 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 11.4 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 10.2 NOTF.: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN wiND SPEEDS ARE LC:SS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. *'•** SEE NOTES AT THE BACK OF THIS REPORT **** -148-. r ~ ·~ & M C(:lN~3tJL TANT~~ > :a: NC • ~- ~~LJS :a: TNA HYDI~ (:JELEC; TR :a:(::: a::ao r~ (:J .:J· L::: c T [- MONTHLY SUMMARY FOR WATANA WEATHER STATION ~-- DATA TAKEN DURING October, 1982 ,J R£5, RES. •• IIAX. 111\X, MY'S [ IIAX, IIJN, tiM 118 \liiii --CUSTP'VM. H -S8UI lAY TtiiP. 1£Jf, 1£Jf. ID. SPI. SPI, ID. SPI. ID. IH ., PIECIP EJEIGY MY Bt JIBC Bt IS IllS IllS IS IllS z DE&t lit IIIIISit r -. 1 3.7 -2.1 •• 218 • 1 •• 2'11 3.8 SE .. ..... 1.1 1831 1 L - 2 2.2 -2.1 .I 162 .9 1.1 Ill 4.4 • .. ..... ••• 2278 2 3 1.8 -2.11 -.4 152 2.2 2.4 131 6.3 Ill H ..... .4 1481 3 [ 4 1.9 -3.3 -.7 149 3.3 3.4 146 7.6 E H ..... ••• 2891 4 5 -.1 -3.5 -1.8 141 4.1 4.1 I3S 8.9 • H ..... ••• 2781 5 6 1.1 -3.5 -1.2 149 4.3 4.4 164 8.3 NE H ..... 1.1 2115 6 7 -.8 -3.8 -2.3 169 3.3 3.8 173 8.9 ENE .. Hill 1.1 985 1 [ 8 -2.3 -5.7 -4.1 261 3.8 3.5 26S 8.9 ltSI .. ..... 1.1 2229 8 9 -1.2 -11,9 -6.1 276 1.4 1.6 257 4.4 II H IIIII 1.1 1468 9 11 -.9 -7.3 -4.1 'lf'l .6 1.1 266 3.8 II H ..... 1.1 1185 11 [ 11 -1.9 -9.9 -5.9 IH IIH 3.5 IH HH Ill H Hill .2 931 11 12 1.8 -4.2 -1.2 162 4.4 4.6 179 11.4 E1E H ..... .2 1181 12 13 -3.3 -18.1 -11.7 152 1.5 2.1 129 8.3 It H IIIII 1.1 1435 13 14 -4.1 -14.5 -9.3 168 1.7 1.9 196 5.1 E H 11tH 1.1 1513 14 [ 15 -4.1 -17.2 -11.6 139 1.8 2.2 m 7.6 It H IIIII 1.1 261f 15 16 -3.2 -11.3 -7.3 167 5.1 5,1 186 11.2 ENE H HIH 1.1 1121 16 17 -.s -7.6 -4.1 112 1.1 1.4 117 3.8 • H HIH 1.1 1641 17 18 -.3 -11.1 -5.7 lllt 1.2 1.5 346 3.8 tl H Hill 1.1 2111 18 [ 19 s.1 -6.6 -.8 16S 1.2 1.5 137 3.8 E H ..... 1.1 1156 19 21 4.1 -4.7 -.3 152 2.3 2.7 126 8.9 • H 11tH 1.1 HHH 21 21 -.1 -7.5 -3.8 144 4.7 4.9 lllt 8.9 Ill H Hill 1.1. ...... 21 L 22 -3.3 -12.1 -7.7 152 5.9 6.1 159 11.2 Ill H IHH 1.1 HHH 22 23 -4.5 -16.1 -11.3 163 5.5 5.7 143 8.9 ENE H ..... 1.1 HHH 23 24 -6.4 -16.8 -11.6 166 4.1 4.2 175 8.9 ENE H IHH ••• HHH 24 25 -4.1 -14.6 -9.3 186 2.2 2.5 lSI 6.3 ENE H ..... 1.1 ...... 25 L 26 -11.1 -22.7 -16.9 181 3.2 3.6 197 8.9 E H" 11tH 1.1 HHH 26 27 -17.3 -27.9 -22.6 154 2.7 2.9 182 8.3 ENE H ..... 1.1 159 27 28 -16.2 -21.2 -18.7 172 3.9 4.1 172 9.5 EIE H IHH !.1 731 28 29 -11.3 -22.3 -111.3 312 .7 1.4 311 3.2 IIIII H ..... .4 ISIS 29 [ 31 -15.1 -32.8 -24.1 IH Hit 1.6 Ill Hll IH •• ..... ••• 18 31 31 -13.1 -24.3 -18.7 156 6.2 4.4 156 11.2 E H IHH ••• 1135 31 IIINTH 5.1 -32.8 -7.11 156 2.7 3.1 179 U.4 ENE H ..... 4.2 38729 L GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 8.9 GUST VEL. AT MAX. GUST MINUS l INTERVAL 7.6 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 8.9 [ GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 8.9 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY L OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** L -149- t R & M CONSULTANTS> INC. SUSZTNA HYDROELECTRIC PROJECT MONTHLY SUMMARY FOR WATAWA WEATHER STATION DATA TAKEN DURING NoveMber, 1992 i RES. RES. AVC. IIAX. t1AX. DAY'S !tAX. MIN. ION WIND WIND WIND GUST GUST P'IJAI.I£AN IQN Sti.AR DAY TEJIP. Te!fl. TEll'. DIR. SPD. SPD. DIR. SP». DIR. RH DP PRECIP EtiERSY DAY DEt;c DEGC DEG C DEC MIS MIS BEG MIS 1 DEC C Hit WH/5011 -------• 1 -3.1 -14.9 -9.1 112 6.3 6.4 013 14.8 ENE !fl !lUi 1.1 1011 2 -1.4 -10.9 -6.2 868 1.5 2.1 064 6.3 E H IHH 8.0 ~ 2 3 -4.3 -13.4 -B.f' 871 2.7 2.9 876 7.6 £HE II HHI e.e 588 3 4 -4.3 -9.2 -6.8 861 4.1 4.1 168 10.2 £!1£ H 1!1!1 o.o 913 4 5 -8.4 -15.7 -12.1 052 2.3 2.4 857 5.1 HE H HUf o.o 9&5 5 6 -11.3 -28.5 -15.9 065 t.2 1.4 045 4.4 E H :.xl!ll 0.0 1529 ~ ~ 7 -12.6 -21.9 -17.3 064 3.6 3.7 064 9.5 ENE 1!1 •••n 0.0 1515 7 8 -11.2 ·16.5 -13.9 064 4.3 4.8 864 11.4 EME H lll!llii o.o ~.,~ .... ~ 8 9 -8.2 -18.5 -13.4 302 .a 1.2 288 5.7 IIMU H lUll o.a 495 9 10 -8.3 -16.7 -12.5 064 3.9 4.8 867 9.5 ENE ** liHH ., 573 18 ... 11 -5.4 -9.5 -7.5 063 t.9 2.1 175 7.6 DE H HH~ 0.1 641 11 12 -1.6 -7.1 -4.4 866 5.9 6.0 082 12.1 ENE 68 -9.1 0.9 758 t'J ... 13 -1.5 -6.8 -3.8 054 3.2 3.6 086 8.9 HE 73 -7.3 0.1 643 13 14 -4.2 -10.2 -7.2 125 1.2 1.3 DOS 3.2 N H I!IH 0.8 798 14 IS -5.8 -17.6 -11.7 065 1.5 1.1 889 4.4 ENE 68 -14.9 0 •• 921 15 16 -10.2 -19.4 -14.8 875 t.7 1.8 073 5.7 ENE 72 -20.4 o.o UO'! 16 17 -16.2 -22.7 -19.5 077 2.3 2.3 073 4.4 E 63 -25.1 o.o 991 17 18 -14.5 -24.5 -19.5 066 2.8 3.0 oat 8.3 ENE 47 -28.9 9.~ 1003 1a· 19 -16.9 -24.7 -28.8 071 5.7 5.a 074 11.4 ENE 46 -28.6 0.1 785 19 20 -13.3 -17.9 -15.6 091 2.4 2.5 811 7.6 E 52 -23.2 0.3 505 20 21 -6.6 -15.1 -10.9 061 3.6 3.a 052 7.6 N£ sa -16.4 0 .•• 521 2! 22 -5.1 -11.2 -9.2 056 1.9 2.8 051 5.1 E 62' -14.0 o.o 459 22 23 -2.7 -5.5 -4.1 056 4.3 4.4 059 7.0 ENE 71 -a.s 0.1 435 23 24 -1.6 -4.2 -2.9 158 4.5 4.5 092 7.0 HE H !!liiH 8.0 620 24 25 -3.3 -tD.9 -7.1 076 4.5 4.6 081 9.5 ENE 73 -11.6 0.1 515 25 26 -5.8 -11.6 -8.7 062 5.7 5.7 067 u.s ENE 66 -13.9 o.o 558 26 2J -3.8 -14.5 -9.2 066 2.3 2.4 165 7.0 ENE 73 -9.2 o.a 518 27 28 -7.2 -16.6 -11.9 071 1.6 1.7 060 4,4 E H HIH 9.9 559 28 29 -7.9 -9.4 -8.2 058 3 ... 3.5 ess 7.6 NE II I HI! I! 0.1 385 29 30 -6.9 -15.:! -tl.t! 035 3.8 4.1 030 19.:! NNE 71 -16.6 a.o ::sa 39 IIDNTH -1.4 -24.7 -10.7 063 3.1 3.3 073 14.0 ENE 62 -16.5 'J 21513 ... GUST VEL. AT MAX. GUST MINUS 2 INTERVflLS 12. l GUST I..'EL. AT MAX. GUST MINUS 1 INTERI.1AL 11 • 4 ~ GUST VEL. AT MAX. GUST PLUS 1 INTER 1JAL 13.3 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 12. 1 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS f'I!~E L£83 THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **"~* SEE NOTES AT THE BACK OF THIS REPORT **** -150- r .• L I~ ~ M C 0 N ~:) l.J 1... T A N T ~:) ,. :1: NC • ~::ii l.J ~:) :1: T N • · H Y X> I~ (:l 1::: 1 •.• a::: C T I~ :1: C P I~ (:) .. T 1::: C T r- MDrnHL."1' SUMMARY FOR WA'i=ANA WEATHER STATION l. DATA TAKEN DUR I NG DeceMber .• 1982 ,I r- RES. RES. AIJG, IIAX. ltAX. ~v·s L IIAX. ltiN. -liiHD IIIND III MD .GUST GUST P'VALISII u SOUil DAY TEMP. TEIIP. TEJtP. DIR. SPD. SPD. DIR. SPD. DIR. Rn DP PRECii' EIOGY DI\Y DEGt DEG C DE&C DE& IVS IVS DEG ltiS % BEG t !tit ilt/Silt r· .. l ~ 1 -14.4 -19.7 -17.1 132 5.5 5.7 825 10.8 Nt£ 66 -21.9 1.0 448 1 2 -17.1 -23.9 -21.5 171 5.3 5.4 171 18.2 ENE 59 -24.8 ••• 498 2 3 -17.7 -24.2 -21.1 185 4.5 4.8 D74 9.5 ENE 6D -26.3 .2 483 3 ('' 4 -15.1 -24.1 -19.6 063 5.6 5.6 863 18.2 EHE 6i -25.& l.il 463 4 5 -7.4 -15.il -u.s 061 6.6 6.7 862 18.2 ENE 72 -15.1 8.0 395 5 6 -S.l -18.8 -8.1 157 6.5 6.6 157 12.1 HE i19 -13.4 .8 458 0 r·: 7 -.9 -5.9 -3.4 182 7.1 7.2 189 14.il E 88 -8.4 2.8 35& i I 8 -1.0 -4.8. -2.9 179 3.6 3.8 179 12.1 ENE .. tfHI .4 3&8 a L~ 9 -2.4 -17.2 -9.8 859 .8 2.8 279 7.1 ENE •• ..... I.Q 42G 9 18 -8.3 -18.4 -13.4 076 3.4 3.5 866 8.9 E 66 -15.5 o.o 375 10 , .. 11 -?.it -11.2 -8.9 063 6.6 6.7 067 13.3 ENE 66 -14.3 1.0 345 11 12 -5.8 -9.2 -7.5 166 6.8 7.1 884 14.0 ENE &9 -12.4 ••• 368 12 13 -3.3 -6.Y -5.1 171 5.7 &.D 077 12.1 Ell .. ..... ••• 375 13 14 -2.9 -10.8 -6.9 177 3.6 3.8 091 8.9 E 78 -12.1 8.1 358 14 r· 15 -2.8 -lD.il -6.7 166 S.l 5.4 074 9.5 ENE 71 -9.2 1.0 383 15 16 -4.5 -11.5 -8.2 165 5.5 5.6 075 12.1 ENE 70 -ll.O 1.1 38i 16 17 -&.2 -12.2 -9.2 068 2.3 (.4 854 7.6 £ 75 -u.s i.& 355 17 [ 18. -7.3 -15.1 -11.6 067 3.1 3.1 867 7.6 ENE fl ..... 8.i 363 18 19 -8.7 -14.6 -11.7 859 5.7 5.7 855 11.2 £li£ 69 -15.9 ••• 350 19 20 -8.9 -17.5 -13.2 866 4.2 4.4 849 9.5 ENE 65 -17.6 u 410 20 21 -14.8 -21.'1 -18.4 177 2.2 2.3 869 5.1 DiE 83 -21.4 i.t 463 21 l. 22 -14.4 -22.i -18.6 07~ 4.2 4.4 179 9.5 £ME 74 -22.4 8.1 475 22 23 -14.3 -2i.il -17.2 162 5.5 5.6 061 9.5 ttl£ 64 -21.2 i.il 485 23 24 -9.4 -18.0 -13.7 176 3.3 3.4 153 7.6 E 69 -18.3 ••• 391 24 25 -11.6 -18.1 -14.9 113 3.1 3.3 155 9.5 E 85 -17.5 1.0 385 25 c 26 -2.5 -13.4 -a.a 162 6.6 6.7 178 11.4 ENE 78 -13.6 i.O 338 26 27 .4 -3.& -1.7 1&5 5.7 5.8 198 12.7 E .. HfH i.l 303 27 28 2.7 -.3 t.a 083 4.1 4.2 881 9.5 E H HHI 2.8 290 28 a 2.t. -3.1 -.3 878 3.4 3.7 175 10.2 E ttl I Hit li.O 348 29 l 30 -l.il -11.6 -6.7 088 .I 1.9 265 c».l E ... ...... 0.8 313 3ii 31 -4.1 -12.5 -8.3 061 2.3 2.5 iSD 7.6 EN£ ltl '**** 1.0 .m 31 11iitfii1 2.i -24.2 -10.4 i68 4.4 4.7 189 14.6 ENE i19 -1~.7 7.0 1206& L GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 10.8 'GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 12.7 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 12.7 r· GUST VEL. AT MAX. GUST PLUS 2 INTERVALS to.a L" i'-ffJTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DA:LL'T r . OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. ***•lt SEE NOTES AT THE BACK OF THIS REPORT **·lt* [ L -~Sl~ l :1: N C . MO~THLY SUMMAR1 FOR ~ATANA ~EATHER STATION DATA TAKEN DU~ING January~ 1983 ( RES. w£5. tW&. ltt\X. IIAX. IIAX. niH. i'iEAit WIND MiND iiND GUST GUST p I VAL tiEAii tiEAH DAY iEitP. TEMP. TEIIP. DIR. SPD. SPD. DIR. SPD. DIR. Rit DP ,.~ :" DEii t DE& i: r ~~-------------~-------------------------.. ----::---~ ;:) t 1 { 4.i ~ -5.7 -~t· 164 5.3 5.4 072 18 • .2 EHE tt '**** B C DE& IVS IVS DEG tVS % DEG t • 2 •4,2 -7.1 -5.7 862 4.8 4.8 159 8.3 EM£ II fHH 3 -e..o -u.s -9.1 153 4.7 4.8 153 8.3 ME 58 -17.3 4 -lJ.o ·25.7 ·18.2 87i 3.1 3.3 188 1.0 E 51 -25.7 5 -20.2 -28.& -24.4 091 3.& 3.7 886 7.8 E 55 -38.9 b -20 .it -2&.1 ·23.4 151 b.lt 6.2 148 11.4 NE 54 -26.6 7 -22.1 -27.2 -24.7 152 5.9 b.D 062 12.1 N£ 56 -30.3 a -21.8 -28.6 -25.2 &76 s.o s.3 161 10.2 ENE 54 -32.8 9 -27.8 -'34.4 -38.7 888 2.9 3.1 178 8.9 ESE 51 -37.5 18 -27.5 -27.5 -27.5 893 4.5 4.5 893 7.8 E 55 -33.8 11 -17.9 -26.9 -19.4 i51 4.0 4.9 810 9.9 E 28 -34.4 12 -2&.5 -25.1 -a2.s 862 5.8 5.9 152 n.8 £HE 48 -32.7 13 -21.1 -25.2 -23.2 ii65 7.2 7.3 159 13.3 EM£ 41 -32.5 14 -14.1 -24.6 -19.4 868 5.0 5.2 169 11.4 EN£ 49 -27.8 15 -4.9 ·20.9 -12.9 169 3.9 4.1 162 9.5 EN£ 6i -19.3. 16 -b.l -10.2 -8.2 860 4.8 4.8 066 18.2 ENE 65 -13.7 17 -5.8 -12.6 -9.2 044 2.0 2.3 167 8.3 it 71 -13.3 18 -4.2 -6.9 -5.6 057 5,9 6.2 075 12.1 EN£ 68 -10.4 19 -&.0 -li.9 -8.5 u&& .5 2.8 072 9.5 ENE 68 -12.9 zo -a.a -10.5 -9.3 147 5.5 5.5 161 8.9 HE 67 -14.2 21 -7.4 -15.2 -11.3 047 5.1 5.2 156 8.3 NE 46 -19.4 22 -3.8 -11.2 -u.s 076 3.o 3.7 DB3 9.5 EN£ 39 -22.1 23 -ii.O -16.4 -11.2 175 3.6 3.7 070 8.3 E at -26.7 24 -a.4 -13.7 -11.1 i62 o.u 6.2 163 12.1 ENE 33 -24.9 25 -8.7 -14.6 -11.7 165 7.4 7.5 165 13.3 DIE 39 -23.8 26 -6.7 -11.3 -9.8 969 7.4 7.6 165 14.6 ENE 52 -16.9 27 -it.6 -13.6 -18.-2 072 3.1 3.3 875 9.5 ENE 64 -15.0 28 -4.7 -lil.7 -7.7 176 1.4 1.6 095 3.8 E ** *"** 29 -8.1 -15.8 -12.0 073 2.2 2.4 097 5.7 E 75 -14.8 36 -~.1 -i4.2 -10.2 ~58 &.4 6.4 iSi 10.2 ENE 77 -12.6 31 -2.2 -b.'1 -4.6 u6l 5.~. 5.4 &75 10.8 ENE 6b -9.8 tiUHTH .... ti-· -~-4.4 -14.1 Ob4 4.;, 4.8 065 14.6 ENE 53 -22.6 --.. DAY'S Slii.Ai PRECIP EHEKGY DAY lilt lii11SQH a.a 425 1 0.8 410 2 1.6 348 J 0.1 495 4 1.0 4i5 5 8.0 435 6 1.0 468 7 C.i 515 8 0.0 511 9 IIH 240 10 1.0 246 11 ... 598 12 i.O 573 tl e.o 515 14 a.o 458 t5 Q.i ~ 16 0.0 475 17 0.0 560 18 1.2 453 19 O.B 565 20 1.0 721 21 o.q 760 22 1.0 791 2J 0.0 Sl5 24 o.o 75i 25 o.o 648 26 1.0 598 27 8.1 693 28 1.0 888 29 o.a BSl lij 0.0 920 31 2.8 17b75 GUST VEL. AT MAX. GUST MiNUS 2 INTERVALS 11.4 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 14.0 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 14.0 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 12.1 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN UNE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY uR rtONTHLY MEAN fOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT TriE BACK OF THIS REPORT **** -192- r I I . r·- I l R '--M (::ON~SUI ... ·rANT~:>> :a: N ':: • ~:> l.J t:> :a: T N A H Y D a~ C) 1::: 1 •.. 1::: (:: T a~ :t: C a~ a~ (:J .:J· a::: ':: T 1 ~ MONTHLY SUMMARY FOR WATANA WEATHER STATION [ ' DATA TAKEN DURING Februaryt 1983 RES. RES. A\lli, 111\X, MX. llitY'S r·· ltAX. IIJI. 11M 111111 1118 111111 CUST GUST P'VAL IIEAII IDf SILM lt\Y TEJit. TEll'. TEIIP. DU. SPI. SPI. Ill. SfD. Ill. RH DP PRE£IP EMERiiY DAY [ DG& IB& DEC& DB IllS IllS B MIS 1 IS C lit 111/SQII 1 .3 -11.2 -s.1 169 4.8 5.1 169 13.3 ME 59 -11.5 1.1 913 1 2 -1.7 -5.3 -3.5 163 5.3 5.5 171 11.8 £liE 77 -7.3 1.1 893 2 l-3 -2.8 -5.7 -4.3 159 5,1 5.1 174 11.8 ME 69 -9,3 1.1 813 3 4 -2.7 -6.3 -4.5 m 5.5 5.6 177 12.1 £liE 62 ·11.8 1.1 833 4 s -2.4 -9.4 -5.9 161 4.7 4.9 171 14.1 E11E 61 -11.7 1.1 1188 s 6 -1.7 -11.7 -6.2 164 4.6 4.9 161 11.4 EJIE 64 -9.3 1.1 1111 6 l' 7 -4.4 -7.4 -5.9 128 .9 2.5 177 8.3 1111 76 -a.a 1.8 931 7 8 -5.1 -13.5 -9.3 341 1.2 1.4 291 3.2 N H HHI ••• 6111 8 9 -7.5 -15.9 -11.7 163 1.2 1.7 186 ••• E 61 -17.5 1.1 781 9 11 -11.1 -17.4 -14.3 174 1.7 1.8 179 5.7 E 68 -18.1 ••• 751 11 r· 11 -13.6 ·21.8 -17.2 175 2.1 2.4 173 5.1 E 68 -22.4 1.1 828 11 12 ·12.7 -22.9 -17.8 174 1.9 1.9 196 5.1 E 64 -24.6 1.1 935 12 13 -14.8 -25.4 -21.1 163 1.7 1.9 166 3.8 ENE 63 -27.3 1.1 1912 13 [ 14 -13.2 -25.4 -19.3 172 2.8 2.9 173 8.9 BE 59 -24.7 1.1 1973 14 15 -n.4 -15.1 -13.3 176 7.1 7.1 178 11.4 Ell 52 -21.1 1.1 1551 15 16 -12.1 -15.3 -13.7 173 8.1 8.1 176 11.4 ENE 47 -22.4 1.1 1631 16 17 -14.1 -19.4 -16.7 177 6.6 6.7 176 11.4 ENE 45 -25.6 1.1 1685 17 l-18 -11.9 -18.1 -14.5 163 7.1 7.2 165 11.4 £liE 56 -21.7 1.1 1245 18 19 -5.1 -13.6 -9.4 151 4.1 4.2 161 8.9 ENE 73 -13.6 1.1 1691 19 21 -5.1 ·12.9 -9.1 166 5.6 5.7 177 9.5 £IE 61 -14.3 ••• 1741 21 21 -4.1 -12.3 -8.2 167 4.1 4.1 166 8.3 £IE sa -14.1 ••• 1845 21 r· 22 -1.1 -11.8 -6.5 163 3.8 4.1 165 9.5 E11E 65 -11.9 1.1 1921 22 L 23 -3.7 -12.3 -8.1 166 5.6 5.7 161 11.4 E11E 56 -14.3 1.1 1918 23 24 -3.4 -8.6 -6.1 lSI 2.9 3.2 168 15.2 £IE 75 -9.8 1.1 1253 24 25 -3.6 -14.4 -9.1 161 3.7 3.9 162 8,9 IE 61 -12.3 ••• 236$ 25 L. 26 -4.8 -9.0 -6.9 155 6.4 6.5 161 11.8 ME 62 ·12.6 1.1 2111 26 27 -3.9 ·12.8 -8.4 156 3.1 3.1 164 8.9 E11E 61 ·13.7 ••• 1928 27 28 -4.2 -9.2 -6.7 159 t.D 1.1 173 3.8 ENE 66 -13.6 ••• 1651 28 [ ltONTH .3 -25.4 -11.8 165 4.1 4.3 168 15.2 £liE 61 -15.6 ••• 38982 GUST VEL, AT MAX. GUST MINUS 2 INTERVALS 8.3 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 8.9 [ GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 14.6 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 8.3 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN r-ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR HONTHL Y MEAN FOR RELATIVE HUMIDITY AND DEW POI,iT. **** SEE NOTES AT THE BACK OF THIS REPORT **** l : l ~ -153-. l :a: N C • ~3 l.J ~=~ :t: T N A H Y l) I~ C) 1::: 1... a::: C T I~ :&: C P' I~ 0 .:J· E C T r··•ui'~ i'1-iL 'r SUMMARY FOR WATANA WEATHER STATION , :UATt-i TAKEN DURING t"1arch ~ 1983 R£5. RES. AUG. 111\X, IIAX. DAY'S MAX. KIN. IIEAft WIND llltw illiiD GUST GUST P 'VAL tiEjH ltEArt SOLAR DAY TEtiF. TEtiP. TEJfil. DIR. SP!i. SFli. Dli!. SPii. DIR. RH Dr PRECIP ENERGY DAY uEG t DEG C DEG C DEG lt/S 11/S liE& tl/5 .. DEG C Hli ilri/SOH .. ----- -2.& -i:i.o -8.2 li27 l.ii 1.2 357 4.4 II *t Utili IH« t33u -8.1 -17.4 -12.8 034 1.6 2.0 lfl! C' ~ HtiE o3 -16.9 UH 2450 2 -.... , ~ -1l.o -21.3 -1o.s 050 4.6 4.4 lilb 6.9 ENE &a -2i1.3 IIHll 2718 3 .; -12.-\ -20.2 -16.3 051 3.3 3.8 ltt4 8.3 ENE &a -19.9 Hill 2001 4 " -i.S -16.4 -12.1 068 3.i 3.6 078 i.b EiiE " -1&.; HU: 1725 5 "' b -&.S -15.4 -11.1 078 s.:; 5.3 072 10.2 ENE 60 -ts.o Hill 2503 6 i -4.9 -15.2 -10.1 053 2.6 2.7 872 11.3 EliE 58 -to.7 *'** ,638 7 6 -5.o -17.5 -11.6 074 3.2 3.2 174 7.6 ENE 53 -19.5 *"* 3025 8 9 -7.6 -20.6 -14.2 072 3.8 3.9 078 12.1 EN£ 49 -22.5 Hilt 4227 9 16 HHII IIHI HHI HI Hill **** Ill **" IH Ill ***** IHI ***"* lQ ll IIHIIl IIIIi !I IIIII lilt llllt IIIII llllt Hilt Ill .. liiHll *"* IIIIID 11 12 1.8 -1.8 0.8 042 3.6 3.6 151 5.7 HE 53 -8.0 IHI 3960 12 13 1.6 -8.9 -4.0 054 4.1 4.2 817 6.8 ENE 51 -10.2 Hllir 291U 13 14 -t.j -6.3 -3.8 052 2.5 2.& Oob 3.8 HE 58 -to.o ***' 2655 14 ... "' -.7 -8.4 -4.6 843 2.8 3.1 136 6.8 HE 66 -8.6 1111 1287 15 lb .b -9.B -4.6 i44 2 ~ ... 2.3 048 '3.8 HE 61 -10.2 lll*t to73 to li -.5 -9.2 -4.9 848 3.0 3.2 Ill 6.2 liE 54 -12.1 IIH 3378 17 18 -.8 -7.1 -4.0 154 3.2 '3.'3 i54 5.7 NE 56 -10.8 "** 492o 18 19 -3.0 -16.1 -6.6 006 4.u 4.1 063 5.7 NE 58 -12.8 til if 24~C 19 20 -2.8 -7.8 -5.3 859 3.3 3.5 078 6.3 ENE 57 -11.8 .... 4110 26 t:l -1.11 -9.1 -5.4 054 4.;) 4.4 875 7.o EN£ 53 -12.7 "** 3471 21 22 -1.9 -9.8 -5.9 854 4-.2 4.3 161 6.3 ME 52 -12.9 .... 4920 22 23 -2.5 -11.7 -7.1 032 2.4 2.7 056 6.3 NE so -15.4 Hll 4152 23 24 -2.o -14.9 -8.8 058 3.\i 3.1 864 6.3 N£ 5b -13.0 **" 3249 24 25 -2.4 -8.7 -5.6 058 4.4 4.4 lb9 8,3 w 55 -13.1 HII o~m 25 26 -2.6 -8.9 -5.8 855 5.4 5.4 161 18.8 liE 53 -13.5 **" 3903 2& .,_ .:.I -4.3 -9.1 -6.7 661 6.6 o.7 853 11.4 EHE 51 -15.2 tilt 422i 2i 28 -2.il -13.4 -7.7 848 3.3 3.4 054 7.0 HE 54 -14.7 **" 4320 2S 29 -1.-4 -tD.B -6.1 859 3.8 4.8 070 8.9 ENE 58 -13.1 Ill* 4523 29 '30 -.5 -13.4 -7.0 155 2.7 2.9 174 5.7 EHE 60 -13.8 *"* 4778 30 31 .9 -18.1 -4.6 851 2.8 2.9 161 6.3 Eft£ 62 -18.0 ltll 4508 31 ""\ liOIITH 1.8 -21.3 -7.6 857 3.5 3.7 070 12.1 EHE 58 -14.8 "** 96091 J GUST VEL. AT MAX, GUST MINUS 2 INTERVALS 8.9 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 10.8 GUST VEL. AT MAX. GUST PLUS l INTERVAL 8.9 GUS I VEL. AT MAX. GUST PLUS 2 Il'lTERVALS 8. 't dtf'f E ~ RO::L.:.TIV£ l"iUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN CJi'IE f'IETEti PEP. SECOND. SUCH READINGS HA\.1E NOT BEEN INCLUDED If.! THE vAiL''( ui~ f:Oi·HHt.i' MEAN FOR RELATIVE !-tUMIDITY AND DEW POINT. ·:~ ... "!:·;:·i. 5E:i:. HwiE.S AT THE BAC:< OF THIS REPORT ***•>-' _.! -154- r f ~ ·~ ~ M C(:JN~:;UI. .. TAN"T·~:; ... :1: N (:; • ~:; l.J ~:; :1: ·y· N A H v I> •~ (:l a::: 1 ... a::: c; T •~ :1: (:: P •~ (:l .:J· m: c: T [ ~ MONTHLY SUMMARY FOR WATANA WEATHER STATION I , DATA TAKEN DURING April~ 1983 RES. RES. tWfi. tiAX. MX. DAY'S [ ' MX. Mitt, IIEAII IIIIID 111111 IIIIID liUST GUST P'VAL tiEM ltEAN SOLAR DAY l£111. TEitP. TEtf. DII. SPI. SPI. DU. SPI. III. RH DP PIECIP EMEKY DAY rc DEiiC DEG C DEGC DR ltiS IVS DEli lt/S % lEG c 1111 WH/SQit 1 1.8 -tl.9 -4.6 158 2.6 2.7 169 6.3 E11E sa -9.1 ••• 4918 1 2 3.6 -lt.l -3.8 146 2.3 2.5 168 7.1 fiE 54 -11.6 ••• 5065 2 r-, 3 .a -11.3 -5.3 168 3.9 4.1 171 13.3 ENE 59 -11.5 9.1 5131 3 [, 4 1.7 -3.9 -1.1 148 1.1 4.9 274 14.6 ENE 60 -6.3 2.1 2143 4 5 1.1 -7.1 -3.1 151 2.4 2.8 173 8,3 ,ENE 63 -6.5 ••• 4013 5 [ 6 .3 -11.3 -5.1 Ill 1.8 2.1 117 5.1 IIIE 58 -11.9 1.1 5288 6 7 .6 -18.6 -5.1 033 1.8 2.1 119 4.4 NilE 57 -11.9 ••• 5383 7 8 2.2 -11.4 -4.1 1St .6 1.3 249 4.4 fiE 58 -11.6 1.0 4313 8 9 2.6 -tl.7 -4.1 322 .6 1.6 278 5.7 tt 69 -12.1 .2 3473 9 L 11 -4.6 -15.9 -11.3 128 1.9 2.1 822 5.1 liE 54 -17.7 8.1 5653 u tt -8.2 -17.0 -12.6 169 4.0 4.1 178 u.a EIIE 63 -18.4 I.D 5615 11 12 .4 -1.0 -.3 154 3.6 3.7 169 5.7 E11E 68 -6.9 8.0 10829 12 13 u D.l 1.1 151 1.7 1.7 ISS 1.9 NE H HtH ••• 7441 13 f' 14 5.1 ••• 2.6 133 1.2 1.4 135 3.2 Ill£ 46 -7.5 .2 13921 14 15 .1 -3.2 -1.6 116 2.7 2.8 199 6.3 E11E II HtH ••• 1271 15 L 16 1.4 -5.1 -1.8 145 2.5 2.8 161 9.5 E1E 62 -6.8 0.8 4878 16 17 6.8 -s.a .5 328 .9 1.1 245 7.1 IIIII 53 -9.9 ••• 5611 17 [~ 18 1.8 -4.2 -1.2 111 3.1 3.7 183 11.2 E11E 58 -7.1 1.0 4158 18 19 3.4 -3.1 .2 857 3.8 3.9 079 11.4 EIIE 47 -11.1 ••• 5571 19 21 3.4 -4.2 -.4 167 2.9 3.2 181 8.'1 E11E 61 -7.4 1.1 4748 28 [ 21 3.7 -4.4 -.4 144 2.4 2.7 881 7.1 IE 53 -6.3 8.1 6188 21 22 6.5 -3.1 1.8 136 .9 1.7 194 5.7 EJIE 56 -4.8 1.1 5863 22 23 4.9 -2.1 1.4 312 ... t.l ~ 5.1 E 63 -2.7 8.1 5168 23 24 8,3 -1.2 3.6 141 2.1 2.2 076 6.3 N£ 49 -4.6 ••• 6968 24 [' 25 10.1 1.3 5.7 152 2.6 3.8 161 7.1 E1E 51 -3.4 ••• 7131 25 0 26 8.9 -1.8 3.6 112 1.7 1.8 Ill 4.4 N 51 -3.9 ••• 8238 26 27 8.7 -2.2 3.3 336 l.l» 2.1 265 6.3 N 49 -3.7 .2 6895 27 28 7.6 -2.8 2.4 344 .9 1.5 Dll 4.4 M 57 -1.8 ••• 4611 28 [ 29 11.4 .3 3.4 275 .7 .9 219 3.2 II H IHII o.o 4181 29 31 7.7 -1.1 3.3 035 1.7 1.9 Itt 5.1 Ill£ 41 -8.3 ... 7525 38 ltOtiTH 11.1 -17.8 -1.1 D4S 1.7 2.5 274 14.6 EJIE 55 -8.2 2.6 171764 GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 11.4 [ ' GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 12.7 GUST VEL. AT MA'X. GUST PLUS 1 INTERVAL 14.6 r' GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 14.0 NOTE; RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY l' OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** L -155-L B U S :1: T N r~ H Y I> I~ 0 1::: 1... 1::: C T I~ :!: C: P J~ 0 ~T a::: C T MONTHLY SUMMARY FOR WATANA WEAHIER STATTON l>ATA TAKEN DliRtNG M..:lv, 1983 RES. RES, AVG. ltAX. ltAX. OAY'S 11Al(. MIN. ItEAM wnm lUND !ltND GUST CUST P'VAL MEAN ~AN SOLAR DAY TEHP. TEMP. TEIIP. DIR. SPD. SPD. DIR. SPD. ·DTR. RH DP P!IECIP ENERGY DAY ~ DEG C DE& c OF.GC DE& M/S 11/S DEG 11/!; l DEG C !4lt WHISQit --- 1 8.0 -3.6 2.2 869 2.7 3.2 OBt 1).9 ef: 5'. -6.1 t.O 6705 2 2.t -.8 .1 279 t.t 1.9 262 5.7 11511 H ***** 6.6 2233 2 3 3.3 -!.6 .9 212 t.S 1.7 214 5.1 !o!SW H liHH .b 5448 l 4 5.1 -2. t 1.5 064 3.6 3.3 870 7.6 EN£ lll §fHll ., ... 6218 4 5 6.0 -l.B 2.1 137 2.3 2.6 867 ?.0 NE ~a -3.5 0.0 !,013 5 b 7.1 -3.3 1.9 i72 2.0 2.6 126 7.6 NNE S4 -3.8 o.o 7523 6 1 10.0 -2.4 3.8 023 2.8 J. 1 000 7,g mt~ 45 -).~ Q.O 7580 ., I 8 tt .1 -1.4 4.9 811 1.6 1.9 003 4.4 N 4b -5.3 o.o 6153 8 9 9.4 -1.8 3.!} 332 1.5 2.0 316 5.1 ~ 51 -2.4 3.1 '5129 '} 10 10.2 .t 5.2 334 1.6 2.3 324 8.3 NM! 41 -b.S o.n. 7320 10 11 11.6 -2.5 4.6 015 1.5 2. t 133 6.3 N 41 -~.6 o.~ 7933 11 !2 9.4 .a 5.1 063 2.3 2.9 189 8.3 NNE 54 -2.2 o.o 5755 12 13 12.6 2.6 7.6 049 1.8 2.4 020 7.0 NNE 47 -1.4 u 5215 13 14 11.1 3.1 7.1 211 1.1 2.2 240 7.8 II so -.3 0.0 5098 14 15 11.1 2. t 6.6 300 t.S 2.0 330 '5.1 !IMW 49 -1.0 8.0 5509 t"' ·.I 16 9.6 .1 4.9 084 3.1 3.7 093 9:s EMf 54 -1.8 ., ... 5525 16 17 6.4 1.8 3.7 262 2.6 2.8 254 9.3 II ** iHIIi 1.2 39&8 17 18 6.7 .6 3.7 274 2.2 2.6 252 7.6 IINW 63 -.5 0.0 4963 1~ 19 ?.8 -.6 4.6 261 t.a !!.6 245 3.9 y 47 -J,Q u :~GSJ 1? 20 lfHH HIH IIHH Hll IHI HH HI HH liH II *"** !fiH Hfllf 20 21 liiiH ****' lflllfl *** IHI '*** Ill llliH '*' ** ~•n• 'Hlff 4¥HH ~1 22 lf!IH IIHI liHH HI HH **** liH HH ... H ***** '*** llf.HII 22 "' 23 8. t 1.8 5.8 294 t.O 2.3 088 7.0 y ** liiHI •• 1351 23 24 10.6 .. 5.7 055 1.8 2.5 G99 7.6 H 50 -2.9 .6 6998 24 ol 25 12.7 -1.2 5.8 272 1.9 2.9 236 3.9 y 52 -t.5 u n23 25 26 8.6 2.1 5.4 254 1.3 2.0 275 10.2 I!SII H HHll 2.8 4038 211 27 tO.~ 1.2 5.8 u72 t.S 1.9 094 5.1 ENE 54 -.:t ••• 4701 21 28 15.6 4.6 10.1 673 2.6 3.4 085 8.3 NF. 50 2.2 o.o 6905 28 29 17.6 6.7 12.2 085 'f ... • .,,oJ 4.0 086 ~.s E 50 4.4 u 4425 29 30 21.1 7.6 13.9 065 1.3 3.2 092 10.2 E 54 6.5 B.O -1698 30 31 12.1 5.1} 9.0 260 2.7 3.0 257 7,6 y .. **"* ~.6 4113 31 MONTH 20.1 -3.6 5.3 021 .7 2.6 275 10.2 II 50 -2.0 15.2 157304 -" GU~T VEL. AT MAX. GUST MINUS 2 INTF.:RVALS 2.5 GUST VF.L. AT MA~. GUST MINUS 1 .r.NTERVAL 9.5 GUST VEL.. AT MAX. GUST PtUS 1 INTFP.VAL 5.7 GUST VF.:L. AT MAX. GUST PLUS 2 T.NTERVALS 3.8 NOTE: RELATIVF. HIJMJDITY I~F.ADT.NGS ARE UNRF.L. IABI..E WI-IF.N WIND SPFFJ>S AI~E' LFSS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEF.N INCLUDJ::D I·N THE DAILY OR MONTHI Y MF.AN FIJR REI ATIVE HUMIJ):rTY Ai'JD :onJ POJNT. ·lt*** SEE NOTES AT THf:: BACK nF THJ.S REP IJRT **•lf* -156- r" I I~ & M (::(:JN~:)UI-TANTB .. :1: NC , [ ' BU~:> :1: T NA H Y l) I~ (:J E:: 1.-1::: C T I~ :1: C 1:> ~~ (:l .:r m: c T [ ~ MGNTHLi SUMMARY FOR DEVIL CANYON WEATHER STATION DATA TAkEN DURING Septe~ber, 1982 r , [ ; RES. RES. ""'· IIAI. IIAI. Dt\Y'S IIAI. 11111. 11011 IIIII 111111 -~'ST GUST P'Wl lEAl ltEAH SllM r··-Dt\Y T£lll, T£lll, T£lll, DD. SPD. SPI. ll•. SPI. III. RH DP PREClP EHEIGY Dt\Y DE&C DE& c DBC IB IllS IllS IB MIS l DE& c lit 111/SQII 1 12.7 4.5 a.lt 2S8 •• .9 128 3.2 liNE 4ft -3.2 1.1 21t71 I [ 2 u.s 4.3 7.7 162 .l 1.1 llt1 3.8 ESE 49 -2.9 3.4 2358 2 3 8.5 4.9 6.7 193 .3 .7 lltl 3.2 H11E 57 -2.2 9.8 1651 3 4 11.2 3.8 7.5 llt9 .3 1.1 151 3.8 ESE 39 -6.6 .2 2565 4 5 15.4 3.1 9.3 196 2.4 2.6 196 9.5 E 27 -8.11 1.8 2115 5 [' It 15.5 7.1 11.3 14ft .6 2.1 121 8.3 NNE 27 -7.5 1.1 1685 6 7 11.7 6.8 9.3 284 .5 ·' 311 ..... liMI 44 -2.6 4.1t 2118 1 8 9.2 lt.3 7.8 243 .2 .5 321 2.5 SS\1 44 -3.8 1.1 1188 8 9 11.2 4.3 7.3 113 .1 .a 291 3.8 SE 54 -1.4 7.8 1311 9 [ 11 11.1 3.2 7.2 112 .4 .9 062 2.5 ENE 4ft -4.5 .2 2131 tl 11 5.8 2.2 4.1 176 .o .a 297 4.4 Sll 62 -2.6 6.4 988 lt 12 9.4 -1.4 4.1 117 .It .9 171 4.4 ENE 39 -9.4 4.6 ·ma 12 13 8.9 3.1 ••• 242 .5 .a 261 3.2 11511 57 -.7 31.0 1331 13 [ 14 8.9 6.4 7.7 147 .t .It 141 2.5 II 61 .9 14.8 till 14 15 15.5 ft,4 ll.O 26ft .2 1.1 341 &.3 11&11 47 -.3 21.8 2391 15 16 9.7 3.5 lt.6 259 1.5 1.9 281 7.6 II 3& -7.4 6.8 2583 16 17 7.2 1.6 4.4 lit .1 .9 138 3.2 ESE 72 •• ..... 1432 11 [' 18 11.1 2.7 &.9 261 .2 1.1 288 3.2 llSi 79 2.9 4.1 1628 18 19 8.3 4.3 6.3 158 .2 .7 274 3.2 5£ 92 5.4 14.4 m 19 21 7.4 3.9 5.7 111 .1 .a 297 3.8 EiiE 89 3.1 1.4 1213 21 21 ll.4 3.2 7.3 188 .3 .9 314 5.1 ESE 67 -1.7 .6 1285 21 [ 22 6.& -.4 3.1 2S5 .l 1.1 311 4.4 IIIII 78 -2.4 1.2 1531 22 23 8.1 -2.8 2.7 212 •• 1.1 2115 3.8 SSII 47 -11.2 1.1 2788 23 24 8.6 -2.9 2.9 113 .4 1.1 121 3.2 EHE ~ -1.9 u 21~ 24 25 9.9 -1.1 4.4 213 .2 .9 17& 3.2 5 59 -3.3 ... 11125 25 [ 26 6.2 1.8 4.1 158 .1 .1 318 3.8 IISY 56 -7.4 4.2 1121 26 27 7.3 -1.2 3.1 198 .2 .9 247 3.2 5 26 -1&.7 1.8 1565 27 28 6.1 -3.1 1.5 129 .1 .9 119 4.4 ESE 48 -11.2 5.2 1131 28 29 lt.9 1.2 4.1 136 .6 .9 112 5.1 SSE 74 1.3 6.6 1251 29 l. 31 5.5 .& 3.1 321 .2 .1 323 2.5 1111 47 -6.9 2.2 1191 31 IIIINTit 15.5 -3.1 6.1 139 .t .7 196 9.5 ESE ~ -3.7 156.6 51515 GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 5.1 r~ GUST VEL. AT MAX. GUST 11INUS 1 INTERVAl. 5.7 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL s.1 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 7.& NOTE: ~ELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN l ONE METER PER SECONn. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. I ~ k*•lt-A-SEE NOTES AT THE BACK OF THIS REPORT *••** I t ~ -157-: l L ..,. "' ~ ' ~ I~ l.'x M c::: C:) N ~=~ l.J 1 ..• T A N ·y-~3 ~ :1: N c::: • ~~ lJ ~3 :r. T N A H Y l) I~ C:) 1::: 1.-E:: c::: T I~ :1: c:: 1:, I~ 0 .. J· a::: C::: T MONTHLY SUMMARY FOR DEVIL CANYON WEATHER STATION DATA TAKEN DURING October) 1982 I RES. RES. AVG. ltAX. ltAX. DAY'S ltAX. IIIN. lUI UIND IIINI UIND GUST GUST P'VAL. ItEM tiAN DAR DAY TEit. TEif. TEif. DIR. SPD. SPD. DIR. SPD. DIR. RH DP PRECIP ENERGY DAY DEGC DEGC DEGC DEG IllS 11/S D£& IllS % DEGC Ill UH/511 • 1 3.6 .6· 2.1 216 .1 .7 278 2.5 IIIII 71 -4.6 .... tl23 1 2 5.5 ·.7 J 2.4 169 .3 .a 324 3.8 SE 48 ·13.7 HH 1688 2 3 4.7 ·1.5.:t 1.6 113 .6 1.1 tl7 8.3. 66 -4.8 .... 1725 3 4 4.1 -4.V -.1 133 1.8 1.2 117 4.4 SSE 61 -5.3 HH 1855 4 5 3.3 -2.8J .3 175 1.3 2.4 131 18.2 ESE 56 -7.7 .... 1941 5 6 4.5 -6.1 . -.8 146 .9 1.2 026 4.4 s 58 -8.2 HH 1791 6 7 .9 -2.9; ·1.1. 127 .5 1.1 139 3.8 ESE 48 -14.1 HH 475 7 8 -.5 -4.2.: -2.4 281 .3 1.1 2SS 4.4 usu 43 ·18.1 1111 981 8 9 .3 -2.7.;~ -1.2 292 .6 .7 317 2.5 Ulll 4 -37.2 HH 375 9 11 -1.3 ~.1• -3.2 318 .9 1.1 323 3.8 Ill 71 -11.8 HH 383 11 1l 1.0 -6.3: -3.2 121 .9 1.1 117 5.1 ESE Tl -7.5 HH 378 11 12 1.8 -1.3. .3 223 .4 .1 314 3.8 su 23 -25.1 HH 395 12 13 -.8 -5.1. -3.1· 189 .3 .6 343 3.8 s 61 -14.7 HH 428 13 14 -1.3 -9.2 -5.3 tt7 1.1 1.1 129 3.2 ESE 78 -7.2 HH 643 14 15 -3.1 -13.2 -8.2 189 1.4 t.7 139 4.4 SE 85 ·11.8 .... 683 15 16 -1.8 -8.5 -5.2 113 1.2 1.3 878 3.8 E 82 -7.7 HH 345 16 17 2.5 -8.2 -2.9 137 .6 .9 125 3.2 SSII 26 ·29.6 IHI 478 17 18 .7 ·10.6 -5.1 tit .a 1.1 115 3.8 E 55 -17.0 IHI 638 18 19 -.9 -5.5 -3.2 158 .6 • 9 ttl 2.5 • 21 -33.8 HH m 19 28 -2.4 -11.4 -6.9 117 t.6 1.7 ttl 5.7 ESE Tl -9.7 HH 713 28 21 -5.7 -13.3 -9.5 044 1.9 2.7 ItS 11.4 liNE 65 -14.7 Hll, 928 21 22 -4.5 -14.6 -9.6 134 1.3 1.5 116 6.3 ESE 61· -14.8 HH 888 22 23 -7.1 -12.5 -9.8 119 2.3 2.4 113 7.1 ESE 61 -16.2 .... 755 23 24 -a. a -13.2 -tt.6 119 2.1 2.1 1tt 5.1 ESE 59 -17.8 IIH 871 24 25 -7.4 -18.1 -12.8 131 1.7 1.8 122 4.4 SE 70 -16.6 .... 78825 26 -11.3 -19.4 -15.4 124 1.4 1.6 118 4.4 ESE 58 -22.5 HH 728 26 27 -14.8 -23.4 -19.1 112 1.6 1.7 112 5.7 E " -23.4 .... 66327 28 -11.3 -15.1 -13.2 113 2.0 2.1 114 5.1 E 82 -15.8 HH 43828 29 -7.4 -19.2 -13.3 115 .9 1.2 141 4.4 SE 85 -16.2 .... 631 29 38 -15.3 -22.8 -19.1 176 1.8 1.9 173 4.4 ENE 81 -22.2 HH 545 38 31 -9.1 -22.7 -15.9 181 2.1 2.1 866 4.4 ENE 79 -21.1 .... 585 31 ltOHTH 5.5 -23.4 '-6.2 104 .9 1.4 815 11.4 ESE 65 -15.7 1111 25252 GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 9.5 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 9.5 GUST VEL. AT MAX, GUST PLUS 1 INTERVAL to .a GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 11 .4. NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** -158- f l j ~-~ r- L ·~ ~ M t::t:JN~:>UI._ TAN'T"~:> ~ :1: N t:: • ~sus :1: TNA HYl>ROEI-Et::·y-1~ :e:c 1:,. I~ t:J .:r F.:: C T r - MONTHLY SUMMARY FOR DEVIL CANYON WEATHER STATION r· DATA TAKEN DURING Nove"ber~ 1982 ) r I£S. I£S • •• 111\X, 111\X, lAY'S t ; 111\X, ltll. lUI IWII •• IIIII QJST CUST P'VI. I£AN -SOLAR DAY TEltP. 1£IIP. TEIIP. Ill. SPD. SPI. Dll. SPI. Dll. IH DP PI£CIP EJIEKY DAY c-BC IGC IGC IB IllS IllS IlK IllS 1 BC lit llt/S8II L . . 1 .2 -9.1 -4.5 121 1.5 1.8 ttl 7.6 ESE 73 -7.5 IHI 653 1 2 -.6 -9.6 -s.t 121 •• .9 185 3.2 s " -5.8 tHt 615 2 [ 3 -2.7 ·12.9 -7.8 ,116 .s .9 171 3.8 E1E 71 -14.5 .... 441 3 4 -.3 -s.s -2.9 125 .9 1.1 171 6.3 ESE " -7.2 tHt 568 4 5 -2.6 -14.3 -a.s 135 .6 .a 132 2.5 SE 89 -8.7 ... 615 5 It -l1.7 -18.1 -14.9 182 1.6 1.7 182 4.4 E 88 -16.8 HH 423 6 L 7 -11.9 -18.5 -15.2 194 2.1 2.3 121 5.1 ESE 81 -18.1 Hit 423 7 8 -7.4 -13.6 -11.5 114 1.7 1.8 091 5.7 ESE 82 ·U.3 HH 341 8 9 -5.7 -8.5 -7.1 194 .1 .s 128 2.5 IISII 13 -38.1 HH lll 9 L 11 -5.9 -13.7 -9.8 • 1.6 1.7 1, 4.4 ESE 79 -11.3 HH liS ll 11 -l.lt -6.5 -5.1 1H 1.3 1.4 lt7 3.8 ESE 41 -24.3 ... 318 11 12 -.5 -6.8 -3.7 131 1.1 1.4 137 4.4 SE 83 -4.3 HH 493 12 13 -.7 -6.5 -3.6 121 1.1 1.3 115 4.4 ESE • -4.2 IHI 541 13 f' 14 -3.2 -9.2 -6.2 176 .7 .9 189 3.8 ENE 21 -34.8 HH 411 14 15 -6.7 -15.3 -U.I 193 1.6 1.6 195 4.4 E 71 -13.1 IHI 365 15 16 -13.1 -16.8 -14.9 187 2.1 2.1 188 4.4 E 92 -16.5 HH 351 16 17 -15.7 -21.4 ·18.6 • 2.3 2.4 197 5.1 E 87 -19.9 HH 351 17 r-18 -15.9 -22.2 -19.1 192 2.2 2.3 191 4.4 E 78 -23.1 HH 391 18 19 -15.2 -21.4 -18.3 us 2.8 2.8 115 7.1 ESE 63 -23.2 ... 418 19 21 -11.1 -15.3 -12.7 us 2.9 3.1 123 6,3 ESE 79 -15.4 HH 338 21 2t -5.8 -11.7 -1.3 193 1.5 1.7 125 4.4 EIE 85 -11.4 .... 393 21 [ 22 -4.6 -7.5 -6.1 113 1.6 1.8 119 5.1 DIE 81 -8.9 HH 378 22 23 -.a ..... -3.4 112 1.1 1.3 113 3.8 ESE 84 -4.4 ... 341 23 24 -1.8 -4.7 -2.9 136 1.4 1.4 138 3.8 SE 91 -3.4 HH 335 24 [ 25 .5 -6.7 -3.1 138 1.4 1.5 159 3.8 SE 79 -5.2 ... 358 25 26 -4.9 -7.3 -6.1 116 2.4 2.4 ttl 5.7 ESE 76 -9.7 HH 3S826 'D -3.8 -u.a -7.1 186 1.5 1.6 114 4.4 E • -1.5 .... 36327 28 -11.3 -14.7 -12.5 181 2.7 2.7 171 4.4 E 95 -13.8 HH 36828 [ 29 -5.4 -11.1 -7.8 197 1.1 1.2 131 3.8 EJIE 31 -15.5 IIH 25129 31 -5.8 -12.8 -8.9 259 .4 .7 276 3.8 II 69 -12.2 IHI 273 31 IIOIITH .s -22.2 -8.9 114 1.4 1.6 113 7.6 ESE 77 -13.6 IHI 12161 GUST VEL, AT MAX. GUST MINUS 2 INTERVALS 5.1 [ GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 5.7 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 5.7 r-GUST VEL. AT ttAX. GUST PLUS 2 INTERVALS 3.8 L NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE. LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY L OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** L -159-L R & M CONSULTANTS~ XNC. ~:; U ~:; :r T N A H Y l) I~ C) m: 1. •• 1::: c: T I~ :s: (:: P I~ (:) .. J" 1::: C T MONTHLY SUMMARY FOR DEVIL CANYON WEATHER STATION DATA TAKEN DURING DeceMber, "1982 ( RES. RES. AUG. IIAX. ltAX. DAY'S IIAX. MIN. IIEAM UIND UIND UIND GUST GUST P 'VAl IIEAH ION Sll.AR DAY T£lll. TEMP. TEIIP. DIR. SPD. SPD. DIR. SPD. DIR. RH DP PRECIP EIIERGY DAY DEG C IIEGC DEGC DEG MIS "'s DEG "'s 'Z DEG C Hit WH/SQK -----• 1 -tt.1 -19.9 -15.5 117 .~ .a 288 3.2 SE 92 •17.7 Hll 268 2 -1s.1 -21.6 -18.4 t2t 1.5 1.7 133 s.1 SE 86 -21.1 IHI 283 2 3 -tt.9 -21.4 -16.7 107 1.2 1.6 125 4.4 ESE 80 -18.9 HH 293 3 4 -13.1 -18.7 -15.9 118 2.3 2.5 125 6.3 ESE 75 -21.5 Uff 343 4 5 -4.7 -t3.t -a.9 ua 1.3 1.3 198 4.4 ESE 93 -11.3 1111 JOS s 6 -1.5 -7.5 -4.5 122 1.7 1.9 ttl 7.0 SE 89 -?.9 **** 333 6 7 1.8 -1.9 -.1 117 2.3 2.4 187 9.5 ESE 91 -2.7 fill 301 7 a 8.1 -1.a -.9 . 134 .7 1.0 385 s.t SE 1t -36.5 IHI 258 a 9 -.6 -14.4 -7.5 067 1.8 1.1 277 5.1 ENE 93 -9.1 IHI 271 9 18 -4.3 -19.1 -lt.7 110 1.6 1.9 141 6.3 ESE 96 -13.3 1111 273 10 tt -4.a -a.7 -6.a 129 2.8 2.1 to a 6.3 ESE 77 -1e.1 HH 295 11 12 -2.3 ;.a -4.6 131 1.5 1.6 124 5.} ESE 77 -7.2 Hll 310 12 13 -.t -s.1 -2.6 145 1.3 1.5 109 6.3 SSE 83 -5.0 HH 328 13 14 -.9 -9.1 -5.1 142 1.1 1.2 124 4.4 SE 83 -6.9 11!!1 319 14 15 .3 -5.5 -2.6 131 1.5 1.7 182 5.7 ESE 73 -6.1 HH 308 15 16 -.3 -5.8 -2.7 134 1.4 1.5 115 4.4 SE 74 -6.7 **** 315 16 17 -2.6 -u.s -6.6 U7 1.8 1.9 117 4.4 ESE 92 -7.5 lfiH JeJ 1? 18 -18.2 -13.9 -12.1 089 1.7 t.a 077 4.4 E 18 -13.0 !1111 JOB 18 19 -6.6 -13.8 -9.8 113 1.1 1.3 122 .4 SE 81 -12.3 !fHI 301 19 20 -5.6 -15.3 -11.5 124 1.6 1.8 123 ).t ESE 74 -tJ.S I !II! JtS 29 21 -15.8 -18.8 -16.9 083 2.6 2.6 071 5.1 E 91 -17.7 liiH ' 311 21 22 -16.0 -28.6 -18.3 075 2.6 2.7 872 5.7 ENE 81 -28.5 !f!ll!!f JDS .,., .... 23 -u.s -17.8 -14.8 099 1.8 2.0 101 4.4 ESE 75 -18.1 lliU 328 23 24 -8.0 -16.8 -12.4 us 2.3 2.5 tt9 5.7 ESE 90 -14.6 H!fl 308 24 25 -7.a •12.7 -10.3 112 2.1 2.3 tt6 6.3 ESE 81 -13.5 IIH 311 25 26 -.a -8.7 -4.8 131 1.2 1.4 101 4.4 ESE 80 -9.4 1!11 310 2& 'D .4 -2.9 -1.3 143 .a t.l 198 3.2 SSE 78 -9.0 1111 253 27 28 ·' -.4 .3 t45 .3 .4 881 t.9 SE to -28.4 Hll 240 28 29 1.7 -.3 .7 179 .6 1.0 252 3.2 SE 11 -27.5 filii 2&8 29 30 -.1 -9.3 -4.7 IH IHI IIH !1!11 IHI HI 5 -37.6 1111 2~ 3C 3t -6.6 -18.4 -8.5 HI IIH 11!1 Ill II!H HI l -46.0 lflll 251 31 tiCHTH 1.9 -21.6 -8.2 111 1.4 1.7 t07 9.5 ESE !J9 -15.7 1111 9143 -' GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 7.0 GUST VEL. AT MAX. GUST MINUS 1 INTER1.,1AL 6.3 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 9.5 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 8.9 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FO~ RELATIVE HUMIDITY AND DEW POINT. ***•» SEE NOTES AT THE BACK OF THIS REPORT *•»** -160- 1' r ~ ·~ 1'!-..e i'1 CON~:3l.JI ... TANT ~:> ·'" :1: NC 0 ~:n.J ~:> :t: T N A H Y l) I~ C) 1::: 1 •.. 1::: c:; T I~ :t: C P •~ (:) .:r ·1::: c:; T I c MONTHLY SUMMARY FOR DEit;LL. CANYON WEATHER STATION r DATA TAKEN DURING Januar!J.· 1983 ~ r' RES. RES. AVIi. MX. IIAX. DAY'S IIAX. "IN. II£AM YINII WIND IIIND .GUST GUST pI VM. ttEAit ltEAH SOLAR DAY TEMP. TE!f. mtP. Dli. SPD. SPD. DIR. SPD. DIR. RH DP PRECIP ENERGY DA"f r'·c DEli C li£GC UEG C DEG it/S IllS »Eli IVS % iiEG 1: !ttl WitiSQi1 i ------ 1 -1.1 -7.2 -4.2 HI 1111 .... HI llltlt IH 82 -~.a HH 265 1 2 -1.4 -4.2. -a.a 114 2.1 2.1 111 5.1 ESE 78 -8.9 1111 268 2 ( -, 3 -4.2 -11.7 -8.1 115 ,9 1.1 117 4.4 ES£ 71 -11.4 IIH 253 3 4 -11.3 -21.0 -16.2 097 1.3 1.5 892 4.4 ENE 87 -18.6 Hill 278 4 5 -17.9 -24.9 -21.4 182 1.5 1.7 892 4.4 E 79 -25.0 .... 278 5 6 -li1.3 -21.1 -18.7 112 2.4 2.5 186 8.9 ESE 67 -22.5 **** 298 6 [ i -17.2 -25.4 -21.3 110 2.5 2.6 094 8.9 ESE 67 -25.4 tl*ll l4i ": I 8 -22.4 -27.0 -24.7 124 1.2 1.5 888 5.1 ESE Oft -2.9.1 **** ~ 8 9 -23.2 -26.4 -24.8 133 2.3 2.4 U9 5.7 SE 57 -30.4 HH 3&l 9 10 -28.2 -26.2. -23.2 123 2.2 2.3 12.1 5.7 SE 52 -29.7 HH 365 10 [ 11 -1&.2 -31.il -24.9 115 1.7 2.0 141 &.3 E 68 -32.1 flit I . 311 11 12 tliiH HHI Hilt ... HH .... IH ..... ... Ill ftHt HH Htttl 12 13 ..... lltltllt tltiH ... lttlt .... IH IIH HI Itt Hlltlt IHI llllfHI 13 [ 14 UBi tiltH llffH ... IHI .... ... 1111 ... Ill ltiHI .... . ..... 14 15 HIH liiHt UHf HI .... litH IH llltl Itt •• lltlllt llllll ...... 15 16 llflltl IIIII Hilt ... 1111 ... . ... .... HI H . .... .... !I Hill 16 17 ...... ltliHI HHI ltll UH Hilt lltlt litH HI H ***" .... ltltiHll 17 f~ 18 ..... fffiHI Hill HI Hfl! IHI IH fHI ... ** llliH 1111 tfllllll 18 19 -5.8 -7.4 -&.6 102 .& .9 274 2.5 SE 58 -16.8 fHI 269 19 20 -5.8 -12.3 -9.1 119 1.5 1.6 111 5.1 ESE 82 -18.1 .... 358 20 21 -4.4 -11.3 -1.9 128 1.& 1.7 124 4.4 SE 54 -14.4 IHjt 42.8 21 [ 22 -a.s -18.0 -13.4 084 2.6 2.6 089 7.1 E ·63 -19.2 .... 418 22 23 l.o -15.u -&.7 12ii 2.3 2.7 131 8.3 ESE 37 -1Y.2 lhlt 583 23 24 -3.8 -9.9 -6.9 188 2.3 2.& 111 9.:5 ESE 33 -28.5 lll!ll 663 24 r . 25 -5.8 -9.9 -7.9 1&4 2.2 2.3 112 8.3 ESE 42 -18.8 .... 551 25 26 -1.9 -7.3 -4.6 115 1.8 z.a 12.3 7.6 ESE 59 -11.3 **** 503 26 (__, 27 -5.5 -U.il -8.1 i99 2.2 2.6 113 6.3 ENE 74 -12.3 *"* 471 27 28 -3.9 -12.2 -8.1 109 1.9 2..1 137 4.4 ESE Ill -11.:5 HH 531 28 [ 21 -5.4 -13.9 -9.7 Q91 2.1 2.3 124 5.1 E 81 -11.& tllt:t .ci'ii 29 30 -4.0 -9.i -6.9 ~21 1.7 1.9 104 &.3 ESE 62 -8.7 .... 533 30 31 1.9 -5.3 -1.7 137 1.1 1.3 115 4.4 SE 73 -4.9 **** 573 31 110nTH 1.9 -:;1.6 -12.1 112 1.8 1.5 100 9.5 ESE b5 -17.3 IHI 9i35 [ GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 7.6 GUST VEL. AT MAX. GLJST.Mii'fUS 1 Ii'fTERVAL 8.9 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 7.0 r_ GUST VEL.. AT MAX. GUST PLUS 2 IWTERVALS 5.! 1"\fOTE: RELATIVE i-iUMIDITY R£ADINGS ARE UNRELIA&LE Wi1EN WIND SPEEDS At<E: LESS THAN l GNE hETER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOi~ RELATIVE i-iUMIDITY AND DEW POINT. )l,-1::)(r'Xo SEE NOTES AT THE :&ACI\ OF THIS REPORT -1:·:t'lt·» L I -161-L R & M CONSULTANTS~ ZNC. SUSZTNA HYDROELECTRZC PROJECT MONTHLY SUMMARY FOR DEVIL CANYON WEATHER STATION DATA TAKEN DURING February, 1993 RES. RES. MIG. MX. MX. DAY'S MX, ltllt. lUI IIIII 111111 111111 GUST GUST P'WI. lUI lUI 50LAI DAY 'T£11t, TEIIP. TEIIP • lB. SPI. SPI, DB. SPI, DB. RH DP PIECIP EIEIGY DAY IBC BC ISC IB IllS IllS IEC IllS 1 DEG C Ill 1111/SIII 1 3.1 -1.5 .9 133 1.6 1.7 112 5.7 ESE 67 -4.4 .... 595 1 2 l.S -2.9 -.7 138 1.4 1.6 142 4.4 SE 78 ·3.7 fHI 613 2 3 .l -3.2 -1.s 135 1.5 1.6 115 7.1 ESE 73 -5.3 .... 615 3 4 1.1 .... -1.S i23 1.7 1.8 199 6.3 SE 69 -6.2 HH 621 4 5 1.1 -6.7 -2.8 119 1.8 2.1 195 7.6 ESE 64 -7.3 .... 713 5 6 1.3 •9,4 -4.1 145 .7 1.2 198 5.7 SSE 79 -5.2 fHI 625 • 7 -2.4 -7.5 -5.1 251 .3 .a 314 3.8 lSI 38 ·22.6 .... 495 7 8 -3.8 -12.8 -8.3 122 .2 •• 193 3.8 ESE Sit -14.4 fHI 448 8 9 -8.9 ·18.5 -13.7 117 1.1 1.2 113 4.4 ESE 94 -16.2 .... 435 9 11 -8.4 -21.1 -14.2 121 .8 t.t 126 s.t E 98 -16.1 fHI Sll 11 u ·11.9 ·21.2 -15.6 191 1.8 1.9 117 4.4 E " -18.7 .... 465 11 12 -11.9 ·22.8 -17.4 189 1.7 1.8 182 s.1 E 83 ·21.5 fHI • 12 13 -14.5 -24.2 -19.4 187 2.1 2.4 U6 s.1 Ell 78 -22.2 .... 5113 13 14 -12.5 -19.1 -ss.8 168 1.5 1.7 lSI 4.4 DIE 74 ·19.8 HH 721 14 15 -s.8 -19.3 -12.6 113 1.9 2.1 123 5.t ESE 61 ·19.2 .... • 15 16 -6.2 -13.7 -11.1 115 2.3 2.4 199 5.1 ESE 47 -21.1 fHI 1M3 16 17 -7.4 ·15.1 ·11.3 128 2.5 2.6 128 6.3 SE 45 -21.9 .... 891 17 18 -8.5 -14.7 -11.6 118 2.1 2.2 191 6.3 ESE 68 -16.8 IHf 628 18 19 -2.2 -13.1 -7.6 118 1.6 1.7 ttl 4.4 ESE 77 -9.6 IHf 741 19 ~ 21 -1.6 -13.2 ·7.4 us 1.5 1.7 189 5.7 SE 71 -11.1 IHf 1183 21 21 .1 -9.6 -4.8 195 1.5 1.6 196 5.1 E 67 -9.3 .... 1141 21 :!2 3.1 -11.7 -3.8 126 1.4 1.7 lt4 5.1 SSE 77 -8.2 HH 1185 22 23 1.7 -8.8 -3.6 121 1.7 1.9 198 7.1 ESE 58 -11.1 .... 1151 23 24 -.a -7.3 -4.1 189 1.9 1.9 IBB 5.1 ESE 78 -5.9 IHf 951 24 25 1.7 -12.7 -s.s 122 1.2 1.6 193 7.6 E 47 -16.5 .... 1.388 25 26 • 5 -4.9 -2.2 125 1.7 1.8 U1 6.3 ESE 67 -8.3 IHf 1363 26 'D 1.1 -9.8 -4.4 117 1.5 1.7 118 5.1 ESE 6lt -ta.l .... 1598 'D 28 -1.1 -7.1 -4.1 178 1.1 1.3 119 5.1 IE 58 -15.7 HH 1288 28 IDITII 3.3 -24.2 -7.5 112 1.4 1.7 195 7.6 ESE 69 -13.1 IIH 22838 GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 3.8 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 6.3 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 6.3 j GUST VEL. AT MAX, GUST PLUS 2 INTERVALS 5.7 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE 11ETER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY DR MONTHLY MEAN FOR RELATIVE HUMIDiTY AND DEW POIMT. **** SEE NOTES AT THE BACK OF THIS REPORT **** -162- r- r ·~ a. M C: (:l N ~:; lJ f. •• ·y-A N T ~:; > :[ NC. l ~ ~3lJ ~:; :1: ·r N A H Y l) R C) a:r. 1 ... 1::: (:; "T" I~ :r. C P •~ (:J .:r m: (:; T [ MONTHLY SUMMARY FOR DEVIL CANYON WEATHER STATION DATA TAKEN DURING March, 1983 r~ IES, IES, AVC. IIAX. MX. DAY'S IIAX. Nlll. -IIIND IIJHD IIINI CUST CUST P'Wl lt£AN lEAH DAR [ lAY TEif. mt. •• DD • SPD. SPD. DD. SPD. DIR. IH DP PIECIP EMEI&Y DAY IECC BC BC liB IllS MIS liS 1/S % DEGC II WHISIIII 1 -2.1 -6.7 -4.4 156 .5 .7 169 2.5 NE 41 -23.3 IHI 81J 1 [ 2 -4.4 -14.1 -9.3 ttl 1.9 2.1 113 5.7 ESE 71 -11.8 Hll 1615 2 3 -a.t -16.5 -12.3 111 2.6 2.8 111 7.1 E ., -15.8 IHf 1628 3 4 -9.1 -16.7 -12.9 118 2.6 2.9 197 7.0 E ., -15.3 Hll 1275 4 5 -4.4 -12.1 -8.3 199 2.2 2.3 121 5.1 ESE 72 -12.2 HH 119J 5 [ 6 -.8 -13.5 -7.2 194 1.8 2.1 196 5.7 E 69 -12.1 Hll 1765 6 7 -1.1 -11.7 -5.9 196 1.7 2.1 131 5.7 EJIE 61 -12.2 IHf 1821 1 8 .1 -14.3 -7.1 187 2.1 2.3 184 5.1 EJIE 58 -15.6 Hll 2169 8 [ ' -2.2 -17.1 -9.7 186 2.3 2.5 198 6.3 EJIE 55 -18.3 HH 2195 ' 11 -6.4 -16.3 -11.4 189 1.7 1.8 115 5.1 EN£ 81 -12.6 Hll 1181 11 11 1.5 -7.3 -2.9 113 1.6 1.8 192 5.7 ESE 81 -6.7 HH 1625 11 12 6.4 -7.9 -.8 118 t.l 1.3 131 5.1 E 74 -6.9 HH 1658 12 [ 13 5.1 -9.2 -2.1 189 1.6 1.9 166 5.1 EJIE 67 -8.3 HH 2378 13 14 2.6 -7.8 -2.6 194 1.6 1.7 174 5.1 E 67 -7.5 Hll 2188 14 15 3.4 -5.1 -.9 195 1.5 1.7 199 5.7 E 11 -5.9 ffH 2123 15 16 3.5 -8.5 -2.5 198 1.7 1.9 191 5.7 ESE 69 -7.4 Hll 2615 16 [ 17 2.8 -11.8 -4.5 ttl 1.1 1.4 196 4.4 ESE 67 -8.4 IHf 2m 17 18 2.6 -tt.9 -4.7 tit 1.6 1.9 lt4 5.1 E 75 -9.5 Hll 2783 18 19 2.1 -13.4 -5.7 181 1.9 2.1 172 5.1 E 71 -11.7 IHI 2811 19 f_ 21 1.4 -7.1 -2.8 191 1.9 1.9 184 6.3 E 64 -8.9 Hll 2913 21 21 2.7 -7.5 -2.4 195 1.6 1.7 164 5.1 E 56 -11.2 Hll 31~ 21 22 3.2 -11.6 -3.7 193 1.7 1.9 116 5.7 E 59 -11.2 Hll 3151 22 23 1.3 -11.2 -5.1 til 1.7 1.9 115 5.1 E 59 -11.9 HH Jt• 23 L 24 .7 -11.1 -4.7 186 1.6 1.8 161 s.t E 64 -9.9 Hll 2575 24 25 2.2 -6.1 -1.9 131 1.4 1.6 117 5,7 ESE 59 -9.3 ffH 3281 25 26 1.8 -5.7 -2.1 115 2.1 2.4 192 8,3 ESE 54 -11.3 Hll 3133 26 27 .5 -7.1 -3.3 117· 2.1 2.3 118 7.1 ESE 52 -12.1 Hll 3325 27 [ 28 2.6 -8.1 -2.7 117 1.7 1.8 168 5.7 ESE 55 -11.8 Hll ~28 29 3.3 -11.5 -4.1 194 2.1 2.1 111 6.3 E 67 -9.9 3561 29 -' Hll 30 3.4 -tl.l -3.8 104 1.7 2.1 111 5.7 SE 65 -9.8 Hll 3688 JD [ 31 5.3 -7.4 -1.1 112 1.6 1.9 183 5.1 E 68 -6.6 IHI 3218 31 ltOII1H 6.4 -17.1 -4.9 199 1.7 1.9 192 1•3 E 66 -11.1 Hll 74842 GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 5.1 [ GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 6.3 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL ?.0 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS ?.6 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN L ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** L . -163-L R & M CONSULTANTS> XNC. ~=~ u ~s :a: T N A H v I> r~ C) e: 1 ... 1::: (:: ·r r~ :r. c: P r~ (:l .:J· a::: c: T MONTHLY SUMMARY FOR DEVIL CANYON WEATHER STATION DATA TAKEN DURING April~ 1983 RES. RES. AVC, JIAX, IIAX. DAY'S IIAX. tllll. JUt ltllll 111111 WIND GUST GUST P'VAL ltEAit IIEAII SOLAR DAY TEIIP. lEltP. TEIIP. DIR. SPD. SPD. DIR. SPD. BIR. RH DP PRECIP ENERGY DAY BC: IIE&C IIRC B "" MIS DB "'s l DEGC "" 11115011 1 5.9 -9.1 -1.6 113 1.7 2.1 113 5.7 SE 71 -6.5 ••• 3711 1 2 6.7 -9.2 -1.3 181 1.7 2.1 178 6.3 ENE 64 -u.e ••• 3963 2 3 5.1 -a.l -1.5 113 1.9 2.2 119 6.3 ESE 62 -7.3 ••• 4168 3 4 4.6 -2.5 1.1 123 1.3 2.5 281 11.2 ESE 68 -4.6 1.1 1691 4 5 1.6 -3.1 -.8 184 .a 1.2 196 3.8 E 71 -8.1 .2 2585 5 6 3.5 -5.4 -t.l 128 1.1 1.6 121 5.1 SE 52 -14.1 .2 4111 6 7 :u -5.4 -.9 121 1.4 1.8 ttl 4.4 ESE 67 -7.3 t.l 4848 7 8 2.6 -5.9 -1.7 352 .5 1.4 328 4.4 tiE 69 -7.6 ••• 2923 a 9 .s -11.8 -5.2 314 .4 1.3 323 5.1 IN 67 -11.7 .2 2888 9 1D -1.2 -12.3 -6.8 075 1.1 1.7 111 &.3 ESE 58 -12.7 ••• 4413 18 tt -4.5 -12.3 -a.4 196 1.2 1.5 161 6.3 E 68 -13.3 1.0 2381 11 12 3.4 -5.9 -1.3 188 .6 1.1 162 4.4 ESE 51 -14.4 3.4 2445 12 13 3.8 -3.1 .4 us .9 1.2 112 4.4 ESE 54 -12.5 4.1 3228 13 ~ 14 4.4 -2.3 1.1 338 .5 1.4 329 6.3 IN 50 -14.1 .8 3471 14 15 3.4 -1.3 1.1 127 .4 .7 liS 3.2 M 29 -22.4 6.0 1971 15 16 5.1 -1.8 1.7 177 .7 1.2 129 7.6 IItlE 58 -7.1 ·3.2 3118 16 17 4.6 -5.2 -.3 115 .o 1.5 251 5.7 " &2 -8.7 1.0 3661 17 18 5.1 -2.7 1.2 173 .9 1.3 154 7.1 ESE 67 -3.6 6.2 3818 18 19 6.1 -1.7 2.2 113 .2 1.6 197 7.1 ESE 61 -6.3 1.8 .4625 19 28 &.a -3.1 1.9 197 1.2 1.6 154 7.6 E 63 -4.7 ••• 4563 21 21 7.6 -3.3 a.2 194 1.4 1.7 118 s.t ESE 59 -6.7 a.a 5381 21 22 7.2 -.6 3.3 282 .3 1.2 'm 3.8 liN 73 ~3.4 .4 3653 22 ..) 23 4.3 ••• 2.2 ltit .4 .9 323 4.4 IIIII 17 -27.5 3.1 2611 23 24 12.1 .9 6.5 183 .5 1.3 147 5.7 EJtE 58 -4.3 ••• 5655 24 25 14.3 .5 7.4 152 .7 1.4 199 5.7 s 52 -1.1 t.l 5638 25 26 12.2 -1.6 5.3 245 .4 1.1 317 3.8 SSE 62 -2.1 ••• 5618 26 27 11.1 -2.3 4.4 175 .2 1.3 188 5.1 E 57 -4.2 1.0 5708 27 28 9.4 -1.4 4.1 358 .6 1.4 323 5.1 ERE 59 -8.3 ••• 3845 28 29 6.9 .6 3.8 271 .3 .7 118 3.2 s 56 -1'l.6 . 5.6 2908 29 30 11.5 -1.6 4.5 134 1.3 1.8 121 6.3 liE 41 -7.4 ••• 6235 31 ltOHTJt 14.3 -12.3 .a 191 .6 1.5 281 11.2 ESE 59 -9.D 33.2 113821 .., GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 5.7 "' GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 5.1 GUST VEL. AT MM<. GUST PLUS 1 INTERVAL 8.9 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 7.b NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY ~ OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** -164- r ~ r~ l ·~ & M C 0 N ~:~ l.J 1... T A N T ~::; :> :t: t-..1 r:~ ~:; l.J S :t: T N A H Y X> I~ D 1::: 1... 1::: C T I~ :1: C P' I~ 0 ~·.t· 1::: C T [" MoJNTHLY SUMMARY FOR DEVIL CANYON WFATHF.R STATtON L DATA TAKEN DURT.iiiG Ma'J, 1983 f-' RES. RES. AVG. ltAX. IIAX. DAY'S L !tAX. lttN. lf'..AN WIND IIINJ YINI GUST GUST P 'IJAI. HEAN I£Aif SOLAR DAY TEIIP. ta!P. TEIIP. DIR. SPD. SPD. DIR. SPD. DJR. RH DP P!!£CIP ENERGY DAY I' DEG C DEC C DEG C DEC HIS lt/S DEC HIS % '!lEG C HM ldH/SOM [ ------------- t tt.O -2.2 4.4 883 .8 t.5 091 s. t ENE 53 -4.4 ., ... '5318 1 2 5.1 ,;; 2.7 304 .5 .9 ~88 3.8 NW 38 -18.7 6.6 2308 2 C' 3 4.9 -.2 2.4 385 .4 .9 335 3.8 WNW i'O -8.4 !?.2 1491 J 4 7.7 -.8 3.5 066 1.3 1.1 023 6.3 EN£ 67 -3.3 Q.O 4658 4 5 9.4 -.9 4.3 089 .6 1.6 889 il.3 ssw 16 -4.~ o.o 4993 ~ L 6 9.1 ·1.5 4.1 057 1.4 2.0 020 7.6 tiME 67 -1.4 Q.O 5523 " 7 11.3 -2.1 4.6 935 1.4 1.9 116 6.3 NNE 59 -2.?. D.l ol!!28 7 9 13.5 -.9 6.4 185 .4 1.5 227 4.4 s 58 -1.4 o.o 6598 8 9 11.9 o.o 6.0 276 .3 1.3 314 5.7 SSII b3 -.'3 Q,l '53'73 1 [ tO 11.1 1.5 6.3 236 .6 1.1 273 5.7 IISII 49 -2.5 0.0 ,;m H tt 12.9 -1.2 s.9 219 .4 1.3 387 4.4 SSII so -2.1 n.o bJ28 11 12 10.7 ?..5 6.6 076 1.1 1.6 127 7.1 NNE 59 . o.o 4688 12 ·" 13 13.2 4.5 8.9 291 .2 1.2 286 3.8 MNW 61 2.1 0.0 4571 13 [ 14 12.9 4,1 8.5 261 .6 1.2 303 4.4 s 1,7 3.5 o.o 4468 1" 15 13.7 2.2 !3.0 272 .6 1.2 '300 '), t !r!W.. !)b .?. O.i 4488 15 16 12.7 .3 6.5 070 .4 1.3 056 &."3 f 4?. -7.9 2.2 3~93 !~ 17 a.t 2.6 5.4 326 .2 !.3 325 ').1 NW 3ll -17.9 4.4 2798 17 I~ 19 8.6 2.6 5.6 283 .5 1.4 320 5.7 tlt.l bb -3.9 .2 425'3 ll?. 19 11.4 1.2 1),3 236 .3 1.4 225 S.1 l:SE ~s -2.9 .~ 1040 ';I;' 2P 14.5 4.3 9.4 2!]9 1.4 t.9 339 7.0 Nil 59 .6 0.0 6095 2q L 21 10.7 4.3 .,;s 294 1.5 1.7 330 !1.3 tr .. '1 -1.6 ~.0 3325 .,. '-' 22 11.3 3.8 7.6 322 .6 1.2 325 5.7 H\1 78 .9 1.4 mt 22 23 18.5 3.1 6.8 286 .2 t.t 013 5. t sv 71 l.d t.2 4001 23 24 12.4 .9 6.7 077 1.2 1.8 094 a.3 ENE 59 -.1 .2 5280 2.1 f ' 25 15.4 -.9 7.3 294 1.0 1.1 296 7.6 IIN!I 63 1.9 u !iBIS 25 26 12.7 2.2 7.5 '316 .6 1.4 295 6.3 WNW 81 3.9 ., 4808 26 ... 27 12.7 1.1 6.9 049 .6 1.4 Gt2 6.3 ESE 70 3.0 0.9 4323 27 28 16.3 3.4 9.9 036 .4 1.6 1GD 5.7 ,. b3 4.8 o.o 5090 28 [ ~ 29 20.1 s.1 12.6 ~94 1.1 1.6 085 7.0 El£ 57 6.6 ·u 4?9f 29 30 19.7 ~.5 14.1 105 .3 1.5 095 3.9 \ISN 65 9.2 0.0 3503 JP 31 11.9 6.5 9.2 251 .3 t.l 252 4.4 ;my 90 7.5 6.1 2165 31 [ tiONTH 29.1 -2.2 6.9 004 .2 1.4 095 8.9 \IH!I 62 -t.2 25.4 143598 GUST \JF:l.. AT MAX. GUST MJNUS 2 INTF.R'JALS 5.7 GUST VEL. AT MA~<. GUST MINUS 1 T.NTER~)AL 5.7 [ GUST VEL. AT MAX. GUST Pl.. US 1 INTF.RI...'Al. 6.3 GUST VEL. AT MAX. GUST PLUS 2 l:NTERVALS 2.5 NOTE: t~ El.A T I 'JE HUMIDT.TY READINGS ARE UNRFLIABl.E t,JHF.N l.aJJND SF'F.EDS ARF. t.FSS THAN L ONE METER PER SF.COND. SUCH READINGS HAt )I';;: NOT BEEN INCLUDED TN THE DAILY OR MONTHLY t1EAN FOR RELATIVE HUMIDITY AND DF.taJ POINT. ·~*** SEE NOTES AT THE BACK OF THIS REPORT *•»** L -165-L I~ & M C Cl N ~;;; U 1... T ~~ N T ~;;; ;-:1: N C • I'IONT!-IL. 'I SUMMARY FOR SHERMAN WEATHER STATION IJ,.;T.::. 1 r.~;EN DURING SepteMoe:-. 1982 RES. RES. AVC. ltAX. ltAX. DA'f'S MX. :tiH. IIEAH IIIHD IIIND WIND GUST CUST P ''.IAL I!ENt !IAN S!I.AR -, DAY TEif, mtP. TEll'. DIR. SPD. SPD. II!. SPD. IIR. RH DP PREC!P Ef.£RCl ~AY -DEC C DEGC IIEGC D£G 11/S ltfl! DEli IVS l DtG C Ill! WH/SQ!I .. 1 16.6 • 0 ,,. 11.3 045 .2 .s 186 5.7 !f:!E 36 -~.3 9.4 3155 2 14.7 3.7 9.2 22l .3 .6 221 3.2 Sil 21 -7.5 11.3 ~JS 2 3 u.s 5.1 8.3 143 .2 .4 143 2.5 HE ~0 -.ll 1.a t84S 3 4 13.8 1.8 7.8 212 • t .4 187 2.5 ssw 16 -12.9 .2 3~:'3 4 5 16.7 3.1 9.9 051 .9 1.1 S47 5.1 NE 20 -9.9 1.5 ~s 5 6 15.3 5.:! 10.3 186 .5 1.1 13S 6.3 ssw 32 -5.7 u t~"' ~111· .. .. 7 14.3 7.5 11.9 214 .9 .9 213 4.4 ssw 40 -3.7 1.8 2&15 7 a 11.9 6.4 9.2 208 .6 .7 218 3.8 ssw 33 -4.6 ., 1878 e .... 9 12.9 5.6 9.3 212 ,Q .3 215 2.5 ESE H Hl·lll D 1718 9 ... 18 12.6 4.8 8.7 837 .1 .3 021 2.5 HE Ill JHH .2 2m tG tl 7.9 -.6 3.1 044 .1 .. 238 5.1 E 51 -3.2 7.6 1198 1l ... 12 11.9 -.4 5.7 848 .4 .s 074 2.5 HE 46 -7.6 3.& 29~!3 12 13 8.7 4.4 6.6 037 .3 .6 oss 2.5 NNE 61 ., 28.~ 978 13 ... 14 11.& 7.1 8.9 047 .2 .3 213 1.9 NNE ** HUll 19.0 94C H 15 17.8 7.3 12.2 246 .t .8 220 5.1 MitE 48 u 29.8 2e93 15 16 12.1 s.a 8.6 223 1.7 1.9 228 18.2 sw 33 -7.8 11.2 20:'1 wlv I !I 17 8.2 2.5 5.4 853 .4 .4 OfiS , ., ..... HE 72 -.1 9.4 119a 17 19 12.0 3.7 7.9 033 .3 .5 212 3.2 E 52 -1.4 lU 1~25 lS 19 9.4 6.8 7.7 284 .1 .4 :!24 3.8 Sll 62 .9 !B.& i.'S 19 20 9.5 s.s 7.5 153 .o .3 243 1.9 ENE 53 .1 6.0 1"l'e" ... c ... ~~ 21 10.0 5.1 7.& 169 .1 .& 217 3.8 NE ll!! I HII 3.4 1291 "j' -· 22 18.2 -.9 4.7 243 .2 .6 214 5.7 IISV II ***** s.o .,, .. , ~-..... " --23 11.8 -3.3 4.3 054 .5 .& 085 3.2 £ u HH* .2 llb! 23 ·-24 9.9 -s.1 2.4 078 .3 .s ?10 ..... 3.2 E H HHll u ~m !4 :!5 11.1 -l.a 4.1 129 .1 .6 2!8 3.8 .. II HHI o.s 220! ~s 26 8.1 2.2 5.2 849 • 3 .. '" 883 2.5 EN£ H IIHll 19.4 1245 2b 27 9.9 ·1.4 4.3 058 .2 .7 207 3.2 liN£ If UHf 6.2 tm .,~ .. I 28 7.3 -3.8 2.2 863 .5 .5 tD3 1.9 ME II "*** 5.4 me 25 29 9.4 2.6 6.8 174 .3 .9 218 4.4 ENE fl HIH 7.4 1605 2~ 30 7.2 2.5 4.9 215 1.0 t.t 198 5.1 SSII H IHH 8.4 l:SS ~t IUIHTH 17.0 -5.1 7.1 163 .t .6 221 18.2 EHE 3S -3.9 232.2 Sn"..& ' GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 5.7 GUST VEL. AT MAX. GUST MINUS 1 INTEP.1.'AL 8.9 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 9.9 GUST VEL. AT MAX. GUST PLUS 2 INTER'JALS 8.9 ~-OTE: ~EL1H!VE HUMIDITY REA&INGS ARE UNRELIABLE WHEN WIND SPEEDS f'i!l::. ,_.:;:~s THI"~;'. Cf'i:: METER PER SECOND. SUCH READINGS HA'~'E NOT BEEN INCLUDED IU THE OAILY ,-.o '"'" MONTHLY ME;-.r~ FOR RELATIVE HUMIDITY AND DEW POINT. :-,. ""'"7;·;, t..==-t~OTES AT THE B.'1Ci< OF THIS REPORT ·~·~·lf·~ ~ .... - -166- r~ r· R '--M t::ONSl.JI._ TAN"T"~3 > J:N(:::. ~5LJ~~ J: TNA HYl>R OE:I_r:::CTf~ :t: C F~ I~ (:l ;J" F.!: l::: T r-: r- MONTHJ_Y SUMMARY FOR SHERMAN WEATHER STATION l DATA TAKEN DURING October. 1982 ' . ~ RES. RES. NJG, MX. MX. lAY'S L MX. IJII. 11M ... liiiiD --GUSTP'WL lUI 11M SIIUI DAY TEIIP. •• •• ID. SPI • sn. ID. SPI. JD, IH 1IP PIECIP EIIICY DAY r: IBC IBC Bt • IllS IllS IB IllS 1 IRC Ill 111118 1 4.5 -.1 2.2 IS9 .2 .4 211 2.5 EJIE H IIHI HH 1318 1 2 1.t. -1.1 3.3 164 .3 .4 349 2.5 ESE H IHH HH -2 [ 3 7.4 -1.a 2.a llt7 .9 .7 lSI 4.4 Ell H HHt HH 2351 3 4 7.8 -5.2 1.3 173 .a .a 196 3.a Ell H IHH HH 2713 4 5 t..1 -5.9 .I 163 1.6 1.7 147 7.6 liE H IHH HH 2,. 5 6 5.6 -1.1 2.3 161 1.4 1.5 175 lt.3 EJIE H IHH HH 1921 6 l" 7 1.a -.a .s 161 .a 1.1 162 4.4 EIE H HHI HH 755 7 L_ a 1.8 -1.6 .1 148 .4 1.1 127 3.2 £IE H IHH IHI ass a 9 2.4 -2.2 .1 216 1.1 .a 212 3.8 5&1 H HHt HH 76l 9 II -.4 -3.5 -2.1 214 2.3 1.2 219 5.t ssu H IHH IHI 1121 11 r 11 2.1 -3.3 -.7 161 1.1 1.1 143 5.7 E1E H IHH HH 76S 11 L 12 2.1 .1 t.t 161 .4 .4 147 1.9 liE H IHH IHI 538 12 13 .s -5.2 -2.4 131 .4 .6 214 3.2 liE II IIIH .... 345 13 r ~ 14 1.3 -u.s -s.t 119 1.1 .7 112 3.a E H IHH IHI 623 14 15 1.2 -14.3 -6.6 141 .7 .6 128 2.5 E II IIIH HH 1511 15 L 16 -.8 -7.5 -4.2 HI HH .1 HI HH HI H IHH IIH 293 16 17 S.l -8.4 -1.7 126 .3 .4 126 1.9 • .. IHH HH 831. 17 L 18 2.4 -11.1 -4.3 153 •• .4 146 1.9 s H IHH HH 1541 18 19 .a -4.2 -1.7 HI HH .3 HI HH HI H IIIH HH 2G 19 21 .1 -13.8 -6.6 HI HH .6 HI HH HI H IIHI IIH 631 21 2t -2.8 -12.a -7.a 167 2.3 2.2 184 7.6 Ell . 893 21 [ II IHH .... 22 -1.5 -10.6 -6.1 158 2.1 2.3 IS1 7.0 IE H IHH HH 1485 22 23 -2.1 -15.5 -a.a 181 1.5 1.6 • 6.3 E H IHH 1111 1241 23 24 -3.4 -19.4 -11.4 176 .6 .7 Ill 3.8 E H IIHI HH 1323 24 L 25 -4.3 -21.5 -12.9 196 .2 .4 124 1.3 E H IIHI .... 1193 25 26 -21.8 -24.6 -22.7 179 .5 .5 m 2.5 EIIE H IIHI IHI 153 26 'tJ IIHI IHH ..... HI IHI IHI HI IHI HI .. HIH .... HIHI 'l1 21 IIHI IIHI HHI HI IHI IHI HI HH HI H HHI HH HIHI 21 L 29 IHH HHI HIH HI HH IHI HI IHI IH H IHH IHI HIHI 29 31 tiiH HHI HHI HI .... HH HI IHI HI H HHI HH HIIH 31 31 IHH HIH HIH HI HH IHI HI HH HI H IIHI HH HHH 31 IIDIIfll 7.8 -24.6 -J,S 161 .a .5 147 7.6 EIIE H HHI IHI 31135 r-' ' GUST VEL, AT MAX. GUST MINUS 2 INTERVALS 5.1 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 5,1 [ GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 5,7 GUST VEL, AT MAX. GUST PLUS 2 INTERVALS 5.1 NOTE: RELATIVE HUMIDITY READI.NGS ARE UNRELIAIJLE WHEN WIND SPEEDS ARE LESS THAN L ONE METER PER SECOND. SUC~ READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** I \ L -167-L -' R & M CONSULTANTS~ :1: NC; • MONTHLY SUMMARY FOR SHE~MAN WEATHER STATION DATA TAKEN DURING NoveMber~ 1982 NuTE: **** l IIAX, 111M. IIEAil DAY TBIP. TEMP • T£111, RES. IIIMD DIR. DEG RES. IIIND SPD. ltiS 1 2 3 4 5 0 7 8 9 11 11 12 13 14 15 16 17 18 19 28 21 22 23 24 25 26 27 28 29 30 IIOitTil BC IECC DECC 1HH IHII iHHHHt HHt ..... HHt fttH IIHI 11tH 11tH HHI HHt HIH litH HIH HIH IHH litH Hill IIHI Hill HIH 1.8 -3.1 -2.1 -7.1 -1.8 -11.6 -11.1 -16.9 ..... Hill HIH HHt litH IHII Hill IIHI IHH HIH lttH HHI ***** HHt u -3.2 -.5 -11.7 .8 -11.9 -5.3 -u.s -7.5 -16.5 -14.& -21.1 -4.9 -14.3 -7.8 -13.0 .8 -21.1 IHII Ill HHI 1H IHII IH HHI HI ........ IHII HI IHII IH tlltt HI IHII HI IIHI 1H ........ -t.lt 181 ...... 035 -6,2 HI -13.5 192 tlltt HI ........ ..... HI IHH 1H tiHt HI IHII IH IHII IH -1.6 038 -5.11 173 -5.1 156 -1.9 848 ..;12.1 175 -17.4 868 -9.6 Ill -11,4 HI -7.9 159 HH Hit Hit HH lfH Hit HH IHI IIU HH HH .9 .2 Hit .1 .... IHI lfH IHI .... 1111 IHI .6 .5 .7 .9 .& .3 HH IHI ,6 GUST VEL. AT MAX. GUST VEL. AT MAX, GUST VEL. AT MAX. GUST VEL. AT MAX. IWG. lllltl SPD. ltJS !lAX. !lAX. GUST DIR. DEC Hit ... Hit "* HH Ill Hit HI Hit HI Hit HI 1111 HI HH IH Hit HI IHI HI Hit HI .7 078 .3 352 ,2 HI .2 192 Hit HI Hit Ill lfH IH HH Ill !1111 HI HH Ill 11111 Ill .6 161 .5 853 .a 191 .9 144 .6 173 .3 881 u 179 ,0 Ill .4 861 GUST MINUS GUST MINUS GUST PLUS GUST PLUS l£Ait GUST P'IJM. I£AH SPD. DIR. RH DP PRECIP ltJS % IIEG C IlK .. IIH IH H Hill HH til H tiHt HHIH H IHH .... ... !II ..... HHIH II HIH HH HI II !IHH Hll Ill H HHI lfll Ill .. Hill HH Ill Itt IHII HH Ill H Hfll HH Ill II IIIII 3.2 E 25 -19.7 i.9 ENE 44 -14.3 HH HI H liHH 1.3 E H HIH HH Ill II HIH HH Ill II Hill HH Ill II IIIII 1111 1H H IIIII 1111 1H II 11tH 1111 HI II IIHI .... "* 3',8 NJIE II Hill 33 -15.1 1.3 EJ1E H 3.2 EKE 26 3.2 NE 34 1.9 ENE 38 1.9 EJ£ 22 .6 Ill 1111 HI 3.8 EME 37 28 l2 Hill -22.4 -25.2 -21.9 -33.3 -21.9 -26.8 -22.1 2 INTERVALS 1 INTERVAL 1 INTERVAL 2 INTERVALS .... HH Hill HH HH HH 1111 .... Hill .... HH HH Hill lfll Hilt HH Hit HH Hit HH Hit lfH H*l lfH 1111 lfH 1111 IIH till 1111 Hll 1.3 1.3 1.3 1.3 ilAY'S SOLAR ENERGY DAY UIIISGit IHHI 1 ...... 2 IHIH l ...... 4 ...... 5 ...... 6 111111 7 IHHll 8 111111 9 IHIII 10 IIHH 11 178 12 278 1J 233 14 171 15 Hltll 16 111111 17 11!1111 18 ...... 19 llfllll 28 ltlllll 21 liHIH 22 275 23 268 24 273 25 271 26 245 27 261 28 191 29 liiD JO 2799 RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. ARE LESS THAN IN THE DAILY SEE NOTES AT THE BACK OF THIS REPORT **** -168- l I L r I ·~ ~ M C:(:lN!!)lJI. ... T"ANT~:; > :1: NC , !!) lJ ~:; :1: T N A HYI>a~ (:lE:a ... l:::cTa~ :a: C a:) I~ D .. T 1::: C T ~- l MONTHLY SUMMARY FOR SHERMAN WEATHER STATION ~~ DATA TAKEN DURING DeceMber, 1982 l- I , .. RES. RES. AIIG. !tAX. ltAX. DAY'S I tiAX. HIM. ItEM' III MD liND IIIttD GUST GUST P'VAL MEAN !IAN SQ.AR t . DAY TEJf. TEitP. TEit~ DIR. SPD. SPD. DIR. SPD. DIR. RH DP PREtlP EN£RGY DAY DEG C DEGC BC lEG HIS HIS DEG HIS % DE&C "" IH/51111 r ,_ l . 1 -12.1 -1a.o -15.1 171 .7 .6 116 3.2 HE H IHII IIH 283 1 2 -16.9 -21.9 -19.4 147 1.2 1.3 029 4.4 NNE H HHI HH 220 2 [ 3 -14.5 -24.5 -19.5 164 t.l 1.1 Ill 3.2 ENE II IIIII IIH 227 3 4 -13.4 -18.2 -15.8 144 1.2 1.2 151 3.8 HE H IHII HH 303 4 5 -2.3 -14.8 -8.2 157 1.5 1.6 183 4.4 HE II IIIII IIH 275 5 6 .4 -9.2 -4.4 055 1.4 1.5 163 s.1 ENE II !IIHI IIH m ~ [ 7 4.0 -1.1 1.5 856 1.4 1.4 146 6.3 NE H Hill IIH 243 ., , a .9 -.4 .3 IH ••• o.o IH o.o IH I! IHII HII 200 8 9 1.3 -ts.a -7.3 111 .2 .a 178 6.3 E II IIHI HH 203 9 10 -5.t -19.4 -12.3 187 .7 .7 t1t 3.2 E II IIIII HI! 258 11 L 11 -2.4 -a.7 -5.6 064 t.5 1.6 838 3.a ENE H IIHI HH 231 11 12 .4 -5.7 -2.7 159 1.4 1.5 042 4.4 ENE H Hill HH 270 12 13 1.1 -7.6 -3.3 163 .a .9 152 3.2 ENE II IHH 11ft 241 13 r 14 -.2 -a.9 -4.6 143 1.1 1.2 33:1 4.4 ENE II Hill IHI ~ 14 15 2.2 -a.7 -3.3 863 1.2 1.3 165 3.a ENE H IHH 11ft 241 15 L 16 -.3 -8.9 -4.6 848 .9 1.8 129 3.2 NE H Hill IIH 238 16 17 -2.a -14.1 -a.s 062 .4 .4 086 1.9 ENE II IIHI HH 231 17 r-18· -13.4 -18.9 -16.2 055 .3 .4 075 1.9 ENE H IIIII IIH 255 18 19 -4.5 -21.1 -12.8 839 .9 t.l 052 4.4 NNE H Hill lUI 228 19 20 -6.3 -16.4 -11.4 056 .9 1.0 112 3.9 ENE H IIIII IIH 263 29 21 -14.9 -22.7 -1a.8 082 .a .a 088 1.9 E II IIHI HH • 241 21 L 22 -19.9 -26.6 -23.3 872 .6 .7 098 2.5 ENE H IHH IIH 2'.8 22 23 -11.2 -22.1 -16.7 054 .a .a 131 2.5 ENE H ..... UH 258 23 24 -9.0 -19.4 -13.7 0&9 .a .9 056 2.5 ENE H IIIII IHI ~ 24 25 -9.4 -17.5 -13.1 168 .7 .a 020 2.5 ENE II IHH !fiH 203 25 L 26 -1.4 -7.5 -4.5 055 1.1 1.2 861 3.8 ENE H Hill Htl :!48 26 't/ .1 -4.3 -2.1 068 .4 .4 182 1.9 ENE II HHI HH 171 ?:1 28 .4 .t .3 163 .4 .2 092 1.9 NE H IIIH Hit 173 29 l. 29 .9 .1 .5 092 .2 .4 112 3.2 NE II IIHI IHI 173 29 30 t.S -5.6 -2.1 221 .s .6 226 2.5 su II IUH lllll :!2:! 30 31 -2.5 -6.7 -4.6 IH HH Hll HI 1111 HI H IIIII flU 165 31 IIOH1H 4.1 -26.6 -8.7 859 .9 .9 846 6.3 ENE H !IIIII IHI 7187 r, GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 5.7 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 5.1 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 4.4 [ GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 3.2 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE L~SS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY !. OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **•lf* SEE NOTES AT THE BACK OF THIS REPORT **** t ~ -169- [" R & M CONSULTANTS~ :1: NC • GUSITNA HYDROELECTRIC PROJECT MONTHLY SUMMARY FOR SHERMAN WEATHER STATION DATA TAKEN DURING January~ "i 983 ~ RES. ~ RES. IWG. IIAX, li\X, DAY'S hAX. ltiM. -WIND iiiHu IUHD GUST bUST p I IJAI. ItEM I1£Aii SOLAR ui\Y Tafil. iEMP. TEMP. DiR. SPD. SPD. DIR. srn. DIR. illt DP PiiECIP OOG"1 DAY »Eb ~ UEiiC Bt DE& it/S lt/S i£ii itJS % fi£GC iltt iltliSwn 1 -.9 -5.6 -3.1 ... lttltt UH tH .... ... H ..... ... . 20& l 2 G.O -5.8 -2.9 1ft .... HH ... HH fH .. .. ... HH 220 2 3 -3.9 -7.1 -s.s *** tHtt HH IH tttll ltU H ..... Uttlt 18d 3 .. -o.9 -20.8 -13.9 fH fHI HH '*I Hll ... ** ***** .... z.;a 4 5 -18.1 -25.8 -21.9 *** HH HH ... IHI ltll II ..... lttlil 2'iii ;, b -14.3 -29.i) -17.2 061 3.4 3.1 i162 7.6 Eft£ ** ***** .... J3ij b i -to.l -29.5 -22.9 058 2.6 2.1 151 i.il EN£ -H IIHf .... 323 i a -to.a -32.2 -24.5 06il t.a 1.5 052 &.9 iiE •• IIIII **** 358 a 9 -21.5 -21.u -23.8 035 1.2 1.3 140 3.& tilE .. litH .. .. 355 9 10 -17.7 -27.8 -22.8 i54 .9 1.2 853 5.7 ME .. flftl 11111 348 10 11 -11.9 -25.9 -18.9 002 4.2 4.4 869 12.1 ENE .. ***** Hilt 528 11 12 -14.2 -11.6 -15.9 ooa 2.4 2.5 850 8.9 EHE ** tiltH HH 438 12 --, 13 -14.3 -17.9 -16.1 068 2.1 2.2 877 7.6 ENE .. ***" Hll 393 ll 14 -1.9 -28.7 -14.3 ISO 1.1 1.2 071 4.4 ENE ** IHII IHI 405 14 15 1.6 -13.5 -6.8 147 1.7 1.8 870 5.7 ENE H llltlf .... 345 15 16 .7 -5.0 -2.2 843 .a .9 054 5.1 ME ** IIIII .... 333 til 17 -3.4 -13.4 -8.4 i62 .3 ·" 215 2.5 EN£ H Hilt .... "a 17 18 2.3 -9.4 -3.6 Bt.o 1.3 1.4 865 7.i ENE •• ..... ltHI 275 li 19 o.a -11.2 -3.1 171 .2 .6 227 5.7 El£ It ..... 811 171 1? 20 tUft ..... IIIII *** **** 1111 ... Hll HI •• Hill .... lfiiU 20 21 It Hit fllltll Hill ... IHt ltlll ... 1111 Hi II "*** .... **"** 21 _. 22 IHII ..... HIH Ill IIH .... IH .... *** ** HIH .... ...... 22 23 tiD I ..... HHI Ill lllltit .... ... .... ... .. ..... .... . ..... 23 24 ..... HIH IIIII Ill HII .... Ill .... ... If IIIII fiH llflitll 24 25 Uti I IHH Hill Ill ltiH 1111 lilt IIH ... •• llltiH .... ...... 25 26 fflll Hill IHH *** I-HI **** ... .... Ill llli filii fiH dlltlf ~ 27 ..... ..... HHI ... II lilt ... .. ... .... Ill It lit HI "** ...... 27 28 ..... IIIII ..... *** .... .... ... IIIII ... II ..... IHI 1111111 28 ':1-~'I ttlltl ..... tDilt ittlt nu .... ••• litH IH H Ultlt tlltlt IIHH 29 J 3u l'llhll'll :tlll11ll11 ..tHII "** I A I'll -.ltlll .... lit II fH n ~ .... Ull Hhlt jij 31 itllft ttllil lttHI ... llltt ltiH ... llltl *" Itt ***" UH lltlltH 31 nuifflt 2.3 -32.2 -tl.i 059 l.b 1.8 069 12.1 ENE •• ..... 1111 5996 GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 8.3 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 8.9 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 10.2 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 7.0 r.iGTE; RELATIVE i-tlJMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAr.i ONE METER PER SECOND. SUCH READINGS liAVE NOT BEEN INCLUDED Hoi ThE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND De:w POINT. ·~*** SEE NOTES AT THE BACK OF THIS REPORT •lt**·~ -170- TNC:. ~S U ~=~ :1: T N A H Y l) r~ (:) t::: 1... r::: (7: ·y· r~ :t: C t=> I~ 0 ... 1" r::: C T MONTHLY SUMMARY FOR SHF.RMAN WF.ATHF.R STATION DATA TAKEN DURINI; Fehruaru, 1983 RES. IES. AVC. IIAX. MX. 1111. lUI 111111 11111 111111 GUST DAY TEIIP. a. TEIIP. ltl. SPJ. SPI. III. liS C IIEG C liS C lEG liS lVS 18 1 IHH 2 HIH 3 IHH 4 HIH 5 IHH 6 HIH 1 -.t 8 -1.9 9 -9.1 18 -7.5 t1 -tl.t 12 -11.5 13 -24.7 14 HIH 15 IHH 16 HIH 17 IHH 18 HIH 19 IHH 21 HIH 21 IHH 22 HIH 23 IHH 24 HIH 25 IHH 26 HIH 'D IHH 28 HIH IIOitllf -. 1 IHH HIH IHH HIH IHH HHI -8.3 -13.6 -21.9 -23.3 -26.1 -28.1 -29.1t IHH IHH IHH HIH IHH IHH HIH IHH HIH IHH HHI HHI HHI HHI IHH -2'M IHH IH IIHI IH IHH IH IHH IH IHH IH HIH IH -4.2 .. , -7.A 172 -15.5 176 -15.4 178 -18.1 159 -19.3 161 -27.2 14.1 IHH IH IHH IH IHH IH IHH 1H HHI IH 11H1 IH IHH IH IHH IH IHH IH IHH IH IHH IH IHH IH IHH IH IHH IH HIH IH -1S.3 169 IIH IIH IIH IIH IIH IIH .4 .2 .5 .4 .5 .3 .4 IIH HH IIH IIH IIH HH IIH IHI HH IIH IHI IIH IIH IIH IIH .4 IIH IH IHI IH IIH HI IIH IH IIH IH IIH IH .6 173 .3 147 .It 145 .5 195 .It 144 .5 141 .4 121 IIH IH HH IH IIH IH IIH IH IIH IH HH IH IIH IH HH HI HH IH IIH IH IIH IH IIH IH IIH HI HH HI IIH IH .!'i 141 GUST VFL. AT ~tAX. GUST MINUS c;tJGT VEL. AT MAX. GIJST MtNUS ~UST VEL., AT ~1AX, GUST PLUS GIJRT lJF.L., AT HAX, f;IJST Pl.lJS !lAX. GUST P''IAI. lt£AN lEAH SPJ. III. IH IP PRECIP 11/!1 l DEC C II HH HI H H1H HR HH IH H H1H HH HH IH H HIH IIH HH IH H IHH HH HH IH H IHH HH HH 1H H H1H HH 2.5 F. H HIH IIH 3.2 E H H1H 1H1 2.5 E H HH1 HH 3.2 F.J1E H HIH HH 2.!i HE H H1H IHI 1.9 F.M£ H HIH HH 1.3 EfiF. H IHH IIH HH IH H IHH HH IHI 1H H IHH IHI HH IH H HIH HH HH 1H H HH1 IIH HH IH H HIH .HH HH IH H HIH IIH IIH IH H HIH IIH HH 1H H IHH HH HH 1H H HIH HH HH HI H IIIH HH HH IH H HIH IIH 11H 1H H HIH IIH IIH IH H IHH IIH HH IH H HHI HH IIH IH H HIH HH 3.2 ENE H IHH HH 2 INTF.RVAI.S 1 • 3 1 INTERVAL 1 .:-t 1 J.NTF.'RVAL 2.5 2 INTERVALS 1 .9 DAY'S StlAR EJIFJI&Y DAY W/5111 HHH 1 IHIH 2 HUll l IHIH 4 HHH 5 IHIH 6 652 1 733 8 113S 9 ttt8 11 1215 1 t 1315 12 391 13 IHIH 14 HHH 15 IHIH 16 HUll 17 IHIH 18 HUll 19 HIIH 21 HHH 21 1H1H 22 HHH 23 IHIH ~4 HHH 25 IHIH 26 HHH 27 1H1H 28 6:155 f [ NOTE: RELATIVE HUMIDITY READ:t:NGS ARE UNRF.'LJA~LF WHF.:N WINll srF.F.:DS ARF tr:ss THAN l" ONF. MF.TF.R PF.R SECONJ), f:;Ur:H REA»T.NGS HAIJE NOT BEEN tNr:LIJDF.:D IN THE DAti..Y OR MONTHLY HF:AN FOR RELATIVE HtJMJDITY AND DrW POINT. **** SF.F. NOTF.S AT THE BACK OF THJS RF.PORT **** -171-f I L_. R ~ M CONSULTANTS> ZNC. SUSITNA HYDROELECTRIC PROJECT MONTHLY SUMMARY FOR SHERMAN WEATHER STATION --, DATA TAKEN DURING March, 1983 IES. IES. AVG. MX. IIAX. DAY'S !tAX. lUll. 1011 111111 IIIMI IIIHD GUST GUST P'IMI. ItEM titAN SI.AI DAY TEJIP. a. lEliP. Ill. SPD. SPD. Dll. SPD, DIR. RH DP PIECIP EIIERfif DAY IIECC IIECC IIECC DEC IllS liS DEl: MIS z IBC II WII/S&llt I HHI HHI HHI IH lfH lfH IH HH IH H HHI IIH ...... I 2 HHI IHH HHI IH lfH lfH IH lfH IH H Hill lfH IHIH 2 3 HHI HHI llfH IH lfH lfH IH HH IH H Hill IHI HHII 3 4 HHI HHI lfHI IH lfH lfH IH lfH IH H HIH HH IHIH 4 5 HIH HHI llfH IH lfH lfH IH HH IH H IIIH IIH HHII 5 6 HHI IHH IHH IH lfH lfH IH lfH IH H HHI HH IHIH 6 _] 'I IHH HHI HHI IH HH lfH IH lfH IH H HfH .... HHH 1 8 fHH IHH flfH HI lfH lfH IH lfH IH H flfH lfH IHIH 8 9 HIH Hill HIH IH HH HH IH lfH IH H fHH IHf ...... 9 11 -2.6 -15.1 -8.9 161 1.2 1.3 014 4.4 ENE H llfH HH 5 11 It 4.4 -7.8 -1.7 156 1.1 1.1 153 3.8 E11E H fHH 11M 1913 11 12 8.6 -8.3 .2 163 1.1 1.2 162 4.4 ENE H Hill HH 1981 12 13 8,6 -11.5 -1.1 168 .9 1.1 1'/6 4.4 ENE H IHH HH me 13 14 5.3 -11.2 -3.1 169 .9 .9 1'15 3.8 ENE H llfH IIH 2271 14 15 8.5 -8.5 ••• 165 .5 ,'/ Itt 3.8 E H fHH IHf 2468 15 16 6.8 -11.4 -1.8 168 .8 .9 176 4.4 ENE H Hill lfH 3181 16 17 6.4 -13.9 -3.8 116 .8 .a 184 4.4 ENE H IIHI HH B 17 18 6.1 -15.7 -4.9 169 .9 t.l 169 s.1 E H HHI lfH 33SS 18 19 5.9 -15.8 -5.1 113 .8 .9 178 4.4 E H IHII HH 3423 19 21 fHH HHf IHH IH HH lfH IH lfH HI H llfH lfH IHIH 21 21 7.1 -11.3 -1.6 169 1.1 1.1 172 4.4 ENE H HHI IHf 3423 21 22 1.1 -15.1 ..... 1'15 .6 .1 185 3.8 ENE H HHI lfH 3528 22 23 5.9 -14.8 -4.5 168 ,'/ .a 179 4.4 DIE H HIH HH 3618 23 24 4.'/ -11.9 -3.6 152 .8 .9 067 3.8 ENE H HHI lfH 2533 24 25 5.2 -8.1 -1.4 163 1.4 1.5 181 5.'1 DIE H IIIH .... 3695 25 26 5.1 -8.3 -1.6 lSI 2.1 2.1 149 7.6 liE H HHI lfH 3435 26 2'1 4;3 -7.9 -1.8 159 t.9 t.9 152 '/.1 ENE H HfH IHf 3663 21 28 5.8 -9.9 -2.1 165 1.4 1.5 IT/ 5.1 ENE H HHI HH 3'198 28 29 7.6 -11.7 -2.1 OT/ 1.1 1.1 171 4.4 E H HfH IHf 3951 29 31 6.5 -12.1 -2.8 172 1.2 1.2 IT/ 5.t ENE H Hill lfH 4228 31 ,, 31 11.1 -8.8 t.l 165 .1 ,8 855 3,8 ENE H HfH HH 3553 31 tiOOH 11.1 -15.8 •2;6 165 1.1 1.1 149 7.6 ENE H HIH HH 66524 GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 5.7 GUST VEL. AT MAX. GUST MINUS t INTERVAL 5.7 GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 6.3 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 6.3 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT **** -172- .. f [ 1- S l.J S :a: T N A --·, .. [_ MONTHLY SUMMARY FOR SHFRMAN WEATHER STATION l DATA TAKEN DURING April, 1983 RES. RES. AVG. MI. HAX. DAY'S !'. MI. IIIN. lUI IIIHD 111111 IIIHI GUST GUST P 'VAL ItEM ltEAH SOLAR DAY T£11P. lEJIP. TEitP. IIR. SPD. SPD. IIR. SPD. III. RH DP PRECIP ENERGY DAY [ ~ DEG C 116 c DEGC DEG IllS ltiS DE& it/S % DEGC lit Wlt/SGit 1 9.2 -11.1 -.s 171 1.1 1.1 882 4.4 E •• ..... 1.1 4243 1 2 9.6 -8.8 .4 169 1.1 1.1 182 5.7 DIE H IHH 1.8 4435 2 [ 3 8.3 -11.7 -1.2 163 1.2 1.2 165 4.4 EM£ .. ..... 1.1 4581 l 4 7.6 -.5 3.6 135 .2 1.9 212 18.2 NE •• ..... 2.2 1903 4 5 5.1 -2.4 1.4 ISl .2 .6 352 3.2 ENE H ..... 2.6 2165 5 L 6 2.6 -11.3 -4.4 196 .a 1.1 121 4.4 E H ..... 2.2 4948 6 7 7.5 -4.5 t.S 114 .1 .2 864 2.5 EN£ '* ..... 8.1 4528 7 8 4.4 -5.4 -.5 235 .a .8 223 4.4 511 H ..... ••• 3988 a 9 3.7 -9.5 -2.9 217 .a 1.1 218 3.8 SSI H ..... .6 3155 9 [ 11 2.6 -11.3 -4.4 196 .8 1.1 128 4.4 E H ..... 1.1 4948 11 11 -1.9 -11.7 -6.8 157 1.3 1.4 135 5.1 £HE H IHH 8.1 2W 1l 12 3.4 -4.3 -.5 139 .t .7 131 3.2 NME H ..... 8.4 2071 12 13 7.4 -3.8 1.8 184 .7 .6 146 3.2 E H Hill 4.1 4438 13 r~ 14 5.1 -.9 2.1 221 .a .9 229 4.4 su •• IIIH 5.1 2715 14 L_ 15 4.5 ••• 2.3 141 .3 .s 211 2.5 NNE H IIHf 14.2· 2175 15 16 7.& -1.1 3.1 166 1.3 t.t 159 5:1 Ell£ H ..... a. a 3911 16 [ 17 5.1 -5.3 -.1 218 .9 1.2 231. 5.1 SSI H ..... .2 4218 17 18 7.1 -t.l 2.9 152 .6 .a 121 5.1 ENE II IIIH 11.1 3581 18 19 7.5 -3.3 2.1 211 .5 1.2 216 4.4 ssu H IIHf 8.1 3908 19 20 9.9 -4.3 2.a 171 .9 t.l 177 5.1 E H HIH 1.1 5030 21 r 21 11.1 -4.5 (,8 193 .6 .a 831 3.a EJ£ H HID ••• 5143 21 L, 22 a.a -2.2 3.3 214 .2 .5 169 4.4 s H ..... 3.4 3513 22 23 7.6 .5 4.1 211 .1 .s 212 3.2 Sll H HHI 6.4 3148 23 24 15.1 .1 7.6 123 .5 .9 Ill 4.4 EME II HHI 1.1 6831 24 r~ 25 19.4 -1.6 8.9 183 .3 .7 196 3.8 E II IIHI 0.8 6818 25 L" 26 14.3 -3.7 5.3 315 .3 .6 315 3.2 1111 II ..... 1.1 6128 26 27 14.8 -3.7 5.6 225 .1 .7 166 3.2 NE II IIHI 1.1 ttlll 27 28 u.s -2.9 3.8 215 .6 .8 212 5.1 S5U II ..... 0.1 4195 28 l ~ 29 11.6 .1 5.4 156 • 1 ... 211 2.5 ENE H HHI lt.l 4245 29 31 13.7 -2.1 5.9 142 1.0 1.2 117 5.1 ENE •• ..... 1.1 ttS88 38 iiiiHTH 19.4 -11.7 1.8 184 .. .9 212 1U' ENE II IIHI 68.1 124381 ,, r~ GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 9.5 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 8.9 GUST VEL. AT MM<. GUST PLUS 1 INTERVAL 8.9 L GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 7.0 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAlLY I OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. **** SEE NOTES AT THE BACK OF THIS REPORT ·lt*** 'L_. L -rh.; L ---· ----~ R & M CONSULTANTS> ZNC. SUSZTNA HYDROELECTRIC PROJECT MONTHLY SUMMARY FOR SHERMAN WEATHER STATION DATA TAKEN DURING Hay~ 1983 RES. RES. AVG. MX. MX. DAY'S MJ(, "IN. !lEAN 1118 IIIND 111111 GUST GUST P'VI. lEAN ltEAII SOLAR DAY TEJII, Tat. TEll'. IU. SPD. SPD. ID. SPI. IIR. RH DP PREC1P ENERGY De\Y BC IIGC DRC DR IllS IllS IB IllS % DE;C "" llf/5011 I 14.4 -3.7 5.4 127 .3 .a 214 4.4 EIIE H ..... .6 5418 1 2 8.2 1.1 4.7 219 1.1 1.2 216 5.1 Sl H ..... 5.1 4123 2 3 8.8 -.1 4.4 218 1.1 1.3 214 4.4 SSII H ..... .8 4618 3 4 ll.9 -1.6 5.2 IS6 .1 1.1 128 5.1 EHE H IIIH ••• 5821 4 5 12.3 -.8 5.8 843 .s 1.1 347 5.7 E H ..... 1.0 6433 5 6 14.3 -2.2 6.1 lSI .8 .9 351 5.7 BE H ..... 0.1 7115 6 7 15.4 -2.2 6.6 141 .6 .9 347 5.1 E H ..... 1.8 6853 7 8 16.9 -2.5 7.2 318 .2 .a 213 3.8 liE H ..... 1.1 6955 8 9 15.1 -.5 7.3 244 .4 .a 263 4.4 SSII H ..... ••• 5913 9 11 14.1 -.8 6.6 233 .5 .9 293 5.1 Sll H ..... 0.1 6283 11 11 16.8 -.8 8.1 341 .2 .a 316 3.8 £SE H ..... ••• 6765 11 12 14.5 2.2 8.4 127 .4 .7 136 3.8 ESE H HiH 1.1 5783 12 13 16.4 2.4 9.4 111 .2 .a 117 3.8 ESE H HIIH 1.0 5783 13 14 16.1 .9 8.5 223 .s I. I 195 5.7 SSII H ..... .2 4833 14 15 14.2 .3 7.3 m .3 .a 234 3.8 E H ..... 1.0 4793 15 16 13.6 -.3 6.7 238 .6 t.l 21a 5.1 IISII H ..... t.l 4183 16 17 u.s 3,1 7.1 222 .a 1.1 184 7 .I 511 H ..... 7.0 3528 17 1a 11.4 2.7 7.1 222 1.1 1.3 225 6.3 Sl .. ..... .6 4838 18 19 12.7 1.6 7.2 216 .5 .9 199 4.4 511 H ..... 1.0 4285 19 21 18.2 t.a 11.0 m 1.3 s.s 234 6.3 \ISU •• ..... 1.0 &015 21 21 11.1 4.6 7.9 216 1.3 1.4 253 6.3 SSII H .IIIH 1.4 3365 21 22 14.5 5.1 9.8 227 .9 1.2 272 5.7 SSII H ..... 2.1 5168 22 23 14.4 4.1 9.3 216 ·' 1.2 227 5,1 SSII H IIIH .4 4973 23 24 16.4 -.1 8.2 178 .6 t.l 190 5.1 SE H ..... ••• 5889 24 25 t.a -2.2 -.2 tiS .2 .2 145 .6 ESE H ..... .4 961 25 26 HHI HHI ..... ... IIH IIH ... HH ... H ..... IIH HIIH 26 27 ..... ..... ..... ... IIH IIH ... IIH IH H HIIH HH HHH 27 28 ..... HHI IIIH IH .... .... ... 11tH ... H IIIH HH HIIH 28 29 ..... ..... HHI IH HH HH ... HH IH H HHI .... ...... 29 31 ..... fHH IHH IH HH HH ... HH ... H IHH HH IHHI 31 31 HHI ..... IHH IH HH . ... ... HH ... H ..... HH ...... 31 ltONTH 18.2 -3.7 6.9 217 .3 .1 184 7.1 SSII H IIIH 19.4 131075 GUST VEL. AT HAX. GUST MINUS 2 INTERVALS 3.8 GUST VEL. AT MA'X. GUST MINUS 1 INTERVAL 3.2 GUST VEL. AT HAX. GUST Pl-US 1 INTERVAL 5.7 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 3.2 NOTE.; RELATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR i'IONTHLY i'IEAN FOR RELATIVE HUMIDITY AND DEW POINT, ·~*** SEE NOTES AT THE BACK OF THIS REPORT ·lt*** -174- SEP 1'182 26H8 !SSN 11118·0424 TALKEETNA, ALASKA TALKEE IU A I RPQR I LOCAL CLIMATIOLOGICAL DATA YU SYC CONTRACT HE! 08SY Monthly Summary lAIIIUOE \2° 18' N LON&IIUOE 1 S0° 06' W ELEVAIION IGROUNOI l45 FEEl ... c "" 1 1 2 3 4 5 6 7 8 , 10 II 12 13 14 15 ,, 17 18 19 20 21 22 23 24 25 26 27 28 2'J 30 TEKPERATUAE °F § "' .. = ' 62 5'1 53 59 57 55 60 56 56 55 H 52 49 52 63• 56 4'J 52 4'1 ., 50 ., '52 48 48 48 'll 45 4'1 47 § "' B "' l 45 43 45 41 4 I 43 47 44 43 45 38 29 42 u 46 44 41 41 4; 44 41 32 29 26 30 39 31 2'J 38 ]7 Uft SUft 1~81 1183 ... ... c ~ c 4 54 51 '' 50 4'1 4'1 54 50 50 50 44 41 46 48 55• so 45 47 47 47 ., 41 41 l1 39 u 42 311 u 42 ;; ... ., '"""' ::>a _, .. ca:: Q,Q ... ... .,.~ ... 3 0 ·2 0 ·1 ·1 5 1 I 2 ·4 • 7 ·1 1 8 4 ·1 2 2 2 2 ·3 ·2 ·• ·3 2 1 ·4 l 2 46 48 H u 46 41 46 H 4& 44 l7 4S 51 42 43 44 H 46 AYG. AYG. AIG. OEP. AVG. 52. 4 1 0 NUft8ER OF DAYS ftAIIftVft l[ftP. 12• < o• 0 WIND iH. P .H. I .:: t ~~vLrts' ... ... .... 11 0 0 Q 0 2'1. 43 ~I ,. 0 0 .37 0 29.5& 8 16 0 0 .43 0 12'1.68 101 b 3 5 ' 02 'l 3.9 8 13 '.: ' l. ; 8 l& 15 0 0 0 029.54~1 16 0 0 03 0 28.i~~ 2.0 2.9 8 OJ ~.1 ;,9 9 Oi " o o 01 o 28.75 11 l.& 'l. 8 12 II , 0 0 '5 0 9 17 IS 0 0 i 15 0 0 19 IS 0 0 . ?5 21 0 I 0 .l2 24 0 0 '1 2 19 0 I 0 1. 2S 1 7 0 0 56 10 0 0 I., IS 0 0 . 4;, 20 0 0 '! 0 • 18 ~ 0 .50 18 0 1 0 '71 18 Q 0 ! 6 19 0 ' 0 22 24 0 0 '03 H 0 I 0 0 28 0 0 ? 26 0 0 0 21 0 1 0 '40 23 0 0 .01 28 0 1 0 '15 21 0 1 0 '19 23 0 1 0 . 12 IOUL fOUL IOUL NU"BEA OF OAtS 1. S4 0 29.22 17 3.5 4 l 0 29. 25 35 I , 5 l. 6 0 29. ll l4 L I 4. 2 10 17 a ll 8 32 0 12'1.46 16 1.1 7.2 IS 16 0 12'1. 70 l4 I. 1 3. 0 ' 02 0 129' 41 l& 2. 7 4 '6 12 35 0 ' 36 0129.34 ~· 3.5 4.8 12 l& 0129.48 19 7.6, '1.0 !8 18 0 12'1. 62 36 ' 3 4. 5 1 02 <l 2'1.41 ~2 4 ' 5.2 16 01 OIH.l1~l 11 1 2.2 7 Ol 0~~~2,1 1.1 4.1 10 34 ~ l2u2 ,o412l U 1 ~ n 0 iH 7l ill ! . 1 4 l 8 2& ? P,9 •• ,28 u l.l 6 IJ a ~'9.46 ,11 .5 2.0 ; ll 0 ~9.42 :2 1,8 5.2 10 15 0 9. 75 21 1 '9 l 8 12 16 0 8 l3 Q P,?.24 34 1.1 5.] 8 18 0 f'' 21 17 . • 1 . • ' 28 IOIIL fOR 111( NOliN: • 1 9 'I 11~ :~ I 7 12 13 14 I , , :! I :! l! I I : :: I 23 I ' • j ; H, I; I·~ ~: • I 21 10 1 . 28 10 2' 10 30 IOIAL l SUft SiJN DEP. OEP. PR[CIPI UllOM ; .01 INCH. 24 0 P. l.O A : 16 lllllat ... ,. AIG. A¥6. -0 suso• ro oArE lOUt IOIAL 1 I 0 P. Q[P. ·12 ·'i GREAI£51 OEPIN ON GROUND or SNOM. ICE P[U£15 OR ICE A-0 041£ i SNOM, ICE P£U£1S ; 1.0 IIICH 0 IHUNOEASIORRS 0 ~AEt!PITAIION S~O~ !C£ PEUEIS GREAIESl IN 24 HOURS INO OAIES HEAVY FOG 0 1. 1 I ·ll 0 CLEAR PAAILI CLOUOY CLOUOY * EXTREHE FOR THE HONTH • LAST OCCURRENCE IF HOR£ THAN ONE. I TRACE AHOUNT. DATA IN COLS & AND 12·15 ARE BASED ON 1 OR "ORE OBSERVATIONS ~T 3-HOUR INTERVALS. RESULTANT Wl1i0 IS THE VECTOR SUH OF WINO SPEEDS AND DIRECTIONS DIVIDED BY THE NUHBER OF OBSERVATIONS. ONE OF THREE WINO SPEEDS IS GIVEN UNDER FASTEST "ILE: F~ST£ST IIILE • HIGHEST RECORDED SPEED FOR IIHICH A HILE OF' WINO PASSES • ALSO ON EARLIER OATEtSI. HEAVY FOG: VISIBILITY 114 PilLE OR LESS. BLANK ENTRIES DENOTE IIISSING DATA. HOURS OF OPS. HAY BE REDUCED ON A VARIABLE ~CHEDULE. $1ATION IDIRECTIOr. IN CO!IPASS POINTS! FASTEST llBSERVEil CIIE IIINUIE WINO -HIGHEST ONE PIINUIE SPEED IOIAECTION IN TENS OF OEGREESL PEAK GUST -HIGiiESi INSTANTANEOUS WIND SPEED !A 1 APPEARS IN THE DIRECTION COLU~NI. ERRORS IIILL BE CORRECTED ~NO CHANGE~ IN SUIIIIARY OAU WILL BE ~NNOTAIEO IN THE .;NIIUAL PUBLIC~TION. I CERIIFY THAT THIS IS AN OFFICIAL PUBLICATION. OF THE NATIONAL OCEANIC AND ATNOSPIIERIC AD111NISTRATION, ANO IS COnPILEO FROn RECORDS ON FILE AT THE NATIONAL CLINAfiC CENTER, ASHEVILLE, NORTH CAROLINA, 28801. lf4~ ACTING DIRECTOR NATIONAL CLIMATIC CENTER n 0 a a .. IIOIAL OCU..C All jUYIROIIUTil OATA AIO/IITIOIAL CliiiTIC C[IT£1 . : . , · moSPHERIC lOftiNISIRAIION IIFORIUIOI SERYIC£ / •sH£Yilt[, lORlN CAROLINA -17'i- r· l I I . [ L [ [ [ I L Nc:c CD::.:: fT'(J) -c:c ....1 c:c ... c:c -;._~; z ... ,......__ UUJ OUJ ::.::: ....1 c:c .__ . · ... ~ ..::.·· OCT 1,.2 tss11 ona-o••• UUEETU, •usu UUE£11U •tRPOAr LOCAL CLIMATOLOGICAL DATA WEA SVC CONTAAC I ft[f 08SY lloathly Summary lAfiiUO£ ~2° 18 " lOIIGIIUO£ 1 ~0° 06' W £l£YUIO. IGROU.OI 34~ rm llllt !ON[ ALASKAN wan t26~28 ... c a 1 i I s (, 1 8 'I 10 " 12 13 14 1~ 1(, 11 18 I~ 20 21 22 2] 24 2~ 26 27 28 29 30 l1 4] 45 u ·~ u 4) 34 15 ]4 12 n l'l 13 32 30 11 36 28 ll ll 28 31 26 21 2l 18 15 16 22 ~~ SUft '1'0 41&. ]I ; '!0" 0 3~ 34 28 24 21 10 28 30 ' 30 ' 26 26 ll 23 20 10 22 18 12 21 22 20 10 s ·1 -~ ·10 ·12 ' -10 ::~ SUR "' 1' 40• l& !~ 33 l1 31 ll 32 2' 31 35 28 2& 20 27 27 20 27 28 ·I 1 -3 -) ., 0 -& ·3 -· ·& ·• I ., -7 ·13 ·5 ·5 ·11 ·4 ·2 -& -a -12 ·18 ·18 4 ·23 2 -24 ll ·ll 6 -19 ·1• -28 l -21 23 30 30 31 2& 26 27 25 18 2& 21 22 21 8 8 7 2 I -5 ' 5 -10 -3 U&. •l&. BEP. •l&. 1 l 0 -··I IIVIII£1 or oars ll" 'o n i 1 ~ ~i i g! H R! H U ! H 1. I ;~ I :! U 10 0 0 u 00 2'1 u ~1 . • l 1 8 24 ! 4 n a o o 11 01 9 1 s 28 0 0 0 0 28.81 1 1.6 ft.1 11 Ol 110 I • ~~ ~ : ~ ~~ ~ i u~ ~~ ~:; u :~ ~: :~ 10 ~ ll o ' ' n _ • ' " 16 1. 4 1 . ~ 1 12 1 o 'o ' 36 0 1 8 I I 'I.H 1~ 2.'1 l.'l 12 16 !0 10 '0 l4 0 8 01 _ 1 'I_ 1'1 16 9. I 'I. 7 11 02 11. 10 0 I o . 1 ~ I 'I l~ 10 I 2 37 0 I 4 .34 3.8 '1.66 I~ 4.3 ~-1 12 16 10 13 1'1 0 5 I I '1.'17 3~ 2.'1 3 .• 13 3~ 10 14 4~ 0 2 ~ 0 0 30-0~ 34 . 8 1. 3 s 1'1 2 s 1 s 18 0 1 5 .24 4.0 '1.73 36 &.3 1.3 ,. 02 38 0 2 8 01 0 '. 81 10 . 4 . , ' 34 45 0 1 8 0 0 30.02 ~· , 2. 3 ' 2& 18 0 1 10 l3 3.1 ' 28 31 0 2 It 0 0 ',, l& 5.3 6.2 13 33 :! ~ :~ ~ g ~n: ~~ :~:~ :u ~: ~~ '' o to o o .a 04 1!4 &.o 1 1 12 12 5~ 0 10 0 0 2'! 10 ~ 1 2 .l 3. 5 7 0 I ~· 0 10 0 0 2'1 10 ~· 1.8 3.1 ' 2'1 &I 0 '0 0 0 12 12 u 0 10 l l , ~3 ~6 l.& ~-1 10 3~ 52 0 1 10 3'1 1.2 '8.'18 ~· 6.0 1.1 14 02 ~'I 0 1& I T 28. '19 ~2 1 . ~ 2. 2 S OS ~~ ~ it g g ~U1 ~~ U U 1~ ~i lOIAl lOlA IUIIIU or OUS IOIAL lOUt FOR IN[ IIOIIIN: 1 " 0 .01 !8.5 01 O£P. O£P. PIIUIPIIUIP Ol'. ·I· PI : 21 ) .01 lltCM. 12 ·0.4 IOIAl ... ttStlal .. ,. 10 7 10 7 10 16 ~ 17 18 , 20 ~ I ~ H 4 J 24 l~ 0 c 26 l 21 10 28 1 ) 21 0 10 ~ 1 )1 SUR SUR n&. "'- susoa to ou tOIAl IGIA !31 I ~~O :~H P£ll£IS & GRUI£$1 II 24 HOVIS hO Oli[S Gl£11[$1 O[PIM 01 GIOUIO or INUIIO[RSTOIM 0 PRECIPI U 01 s•OM IC[ P lUIS SilO•. IC£ PEllETS 01 IC[ AID OAT£ i)(P_ OlP. NUn fOG l 46 • 8 8. l • ll• . . ClUA P•A lf ClOUDY C OUDY * EXIREIIE FOR THE IIONTH -LAST OCCURRENCE IF "ORE THAN ONE. I TRACE AIIOUNI. DATA IN COLS & AND 12·1~ ARE BASED ON 7 OR HORE OBSERVATIONS AT l·HOUR INTERVALS. AESULIANT WIND IS THE VECTOR SUH OF ii!ND SPEEDS AND DIRECTIONS D.IVIDED BY THE NUIIBER OF OBSERVATIONS. ONE Of THREE WIND SPEEDS IS GIVEN UNDER FASTEST IIILE: FASTEST IIILE • HIGHESt RECORDED SPEED FOR WHICH A HILE OF WIND PASSES • ALSO ON EARLIER DATE lSI. HEAVY FOG: VISIBILITY 114 HILE OR LESS. BLANK ENTRIES DENOTE IIISSING DATA. HOURS OF OPS. !lAY BE REDUCED ON A VARIABLE SCHEDULE. STATION !DIRECTION IN COHPASS POINISI. FASTEST OBSERVED ONE IIINUTE WIND • otiGIIEST ONE HINUTE SPEED !DIRECTION IN TENS OF OEGAEESI. PEAK GUST • HIGHEST INSIANUNEOUS WIND SPEED iA 1 APPEARS IN TilE DIRECTION COLU"NI. ERRORS WILL BE CORREC'ED QNQ ~HANGES IN SUHHARY DATA WILL BE ANNOTATED IN IHE ~i>j'otJAL l'UBLICHiON I CERIIFY THAT THIS IS AN OFF'CIAL PUBLICATION OF THE NAJIOIIAL OCEAIIIC AND AT"OSPHERIC AOiiiiUSTAAHON. AND IS CO"Pil[J FRO" RECORDS 011 FILE AT THE 11Arl0111l CLI"AJIC CENTER, ASHEVILLE, !lOATH CAROLINA, 28801. I ~-};h,J- n 0 a a Ill IOUl GCEIIIC 110 /£1JII011(1Ul DIU 110/UfiOIIl CLIIUIC CEII£1 ACJIIIG DlliECTOR llftOSPII£1lt IOIIIISIRATIOI IIFOIIUIGI 5£1fiCE I •siiUill£, 101111 CIIOLIIA IIAJIOIIAl Cl!"AJIC CEIITER -176- t I ' i ' '~~ c·· t NOV "82 26528 UUEET .. , ALASU IAU((IU AIRPORT LOCAL CLIMATOLOGICAL DATA MU SVC CONIAACI ft(T 08Sl lloatlaly Summary [l£111101 16ROUIIOI 345 r([l OESI££ ~us oi(UM(I TtP(S 511811 11(11&(! iii NO s•• COtERI TE•.PERATURE 0 f 1(£ PR[CIP IIIII OM ~~s:.~ SUISNINE US£ U 0 r 1 rOG P(ll£15 '"·P.H. 1 I f!•f .. 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II& !41 ' ".' . 1 0 > .01 IIICII. •0.09 • IIUIII£1 OF DUS su I IODAT !~a l~..'UL£15 1 GRUI[ST IN 24 HOURS AIIO DAlES GRUT(SI O£PIH 01 GROUIIO or 0 ftll RUN 1£11P. "INIIIIIft 1£11P. 4 I INU ·~ 0 PR CIP mo• SNOM IC P£LL£1 S 511811, ICE P(LL[IS OR It£ INO O.r£ s 12" ' ov -on·. An 0 . a 1 29·10 29 JO 30 JU -~ CL£11--~-T .. ll CLOUDY CLOUDY I EXTREftE F'OR THE "ONTH -LAST OCCURRENCE IF "ORE THAll ONE. I TRACE A"OUNT. • ALSO ON EARLIER DATEISI. IIEAYl FOG: VISIBILITY 114 ftllE OR LESS. BLANK ENTRIES DENOTE ftiSSIIIG DATA. HOURS OF OPS. I!AY BE REDUCED ON A VARIABLE SCHEDULE. DATA IN COLS o AND 12-IS ARE BASED ON 7 OR IIORE OBSERVATIONS ar l·HOUR !IITEAVALS. iiESUt.IANT 111110 IS ~HE VECTOR SU" or IIIIID SPEEDS AND DIRECTIONS OIVIDED BY THE NUftBER OF OBSERVATIONS. 911E OF THREE WIND SPEEDS IS GIVEII UNDER FASTEST NILE: ~ASTEST TilLE • HIGHEST RECORDED SPEED F'OR IIHICH A l!lLE or IIIIID PIISSES STATION !DIRECTION IN COIIPASS POINTS!. fASTEST OBSERVED ONE ltiNUTE WINO -HIGHEST ONE ftiNUTE SPEED IOIAECTION Ill TEllS OF OEGREESI. PEAK GUST -HIGHEST INSTANTANEOUS WIND SPEED lA 1 APPEARS IN THE DIRECTiON COLUitlll. ERRORS WILL BE CORRECTED AND CHANGES IN SU""ARY DATA WILL BE ANNOTATED Ill THE ANNUAL PUBLICA T[ ON. I CERTIFY THAT THIS IS All OFFICIAL PUBLICATIOII OF THE IIATIOIIAL OCEAIIIC AIIO ATIIOSPHERIC ADIIIIIISTRUIOII, UO IS CC.1PILEO FAOII RECORDS 011 FILE AT THE IATIOIIAL CLIIIATIC CENTER, ASHEVILLE. NORTH CAROLIIIA, 28801. I~#NI D 0 a a IAJIOIIL OCUIIC Ill /[1111-ITil DATI AII/IAUIIAl CLIHIIC CliT[I ACTIIIG OIUCJOR . · · · UI8SPHUIC IDIIIISTIAJIOI IIFOIIIAIIOI S(lflt[ / ASHUILL[, IIOITM CIIOLIIII IIAJ!OIIAL CLIRntC CEIIJER -177- ! ' I I I I l [' [ L L [ [ [ ' L_. ~ Nc:x:: Q')~ a" en -ex:: _J ex:: .. ·c. ;,.· ex:: .._, z U!- I.UUJ OUJ ~ _J ex:: 1- r' •. ,...., Q:_-¥:: DEC 1'82 2&528 rAL~EEr•A. ALASU !~l•EEiU AIRPORT LOCAL CLIMATOLOGICAL DATA W(A )VC CONTRACT ~£! 08Sr Moathly Summary llll1UO[ &2° !8' H LONGI1U0[ 150° 06' W 62 71 70 &6 43 29 19 18 3& 0 33 23 32 0 l3 23 33 32 0 I 2S IS 21 40 0 11 1 4 S4 0 14 s IS St 29 20 21 3& 27 18 20 38 28 ,, 31 28 ,, 21 31 33 28 20 21 31 31 21 13 21 44 12 8 0 4 S7 2& IS 7 ' so 28 I' II 13 46 10 4 &I l ·• • 1 1 " IS , • 2 S& 22 ' 48 23 10 47 1& 37 2' 33 30 28 • EATREIIE FOR. THE IIONTH • LAST OCCUARI'NCE IF' !!ORE THAN ON£. T !RACE A"OUNT. • ALSO ON EARLIER DATEISI. HEAVY FOG: VIS181LITT 114 IIILE OR LESS. BLANK ENTRIES DENOTE "ISSING DATA. IIOURS OF OPS. IIAY BE REDUCED Ott A VARIABLE SCHEDULE. [l[VIIIQN tGROUNOI l4S F[£1 2' 29 29 2' 2' 28 21 27 2& 2S 2S 24 24 24 24 24 24 24 24 24 24 2C 24 24 24 0 0 0 0 0 0 r 0 0 0 0 0 0 0 0 DATA IN COLS I> AND 12-IS ARE BASED ON 7 OR !lORE 08SEAUTIONS AT 3-HOUR INTERVALS. RESULTANT IIINO IS THE VECTOR SUI! OF IIINO SPEEDS ANO DIRECTIONS DIVIDED BY THE NUIIBER OF OBSERVATIONS. ONE OF THREE IIIND SPEEDS IS GIVEN UNDER fASTEST !Ill£: FASTEST IIILE • !IIGHEST RECORDED SPEED FOR IIHICH A IIILE OF IIIND PASSES SUT:ON !DIRECTION IN COMPASS POINTS!. FASTEST OBSERVED ONE IIINUTE IIIND • HIGHEST ONE MINUTE SPEED !DIRECTION IN TENS OF DEGREES!. PEAk GUST • HIGHEST INSTANTANEOUS IIIND SPEED lA 1 APPEARS IN THE DIRECTION COLUMNI. ERRORS IIILL BE CORitECTED AND CHANGES IN SUIIIIART DATA llllL BE ANNOTATED IN THE ANNUAL PUBLICATION. I CERTIFY THAT THIS IS All OFFICIAL PUBLICATION OF THE NATIONAL OCEAIIC AIIO AJ"OSPHERIC AO"IIIISTRATIOII, AIIO IS CORPILED FROR RECORDS 011 FILE AT THE NATIONAL CLiftATIC CENTER, ASHEVILLE, NORTH CAROLINA, 28801. lf4.~ D 0 a a IUIOIAl OCEAIIC UD jEIJIIDII(IIAL OAII AIO/IITIOIIl CliiiiiC CEIT£1 ACTING DIRECTOR • · · .. · AIROSPH£RIC ADIIIISIRUIOI IIFOIIUI .. UIJIC£ / ISM£Ull[, IOITH CIIOllll NATIONAl CLI"ATIC CENTER -l78- -I l ("')~ CD~ a" (f) -~ ....J ~ ... ~ z ZJ-- ~LaJ 'ILaJ ~ ....J ~ 1-- JAN I'B3 TALKEETNA, ALASKA IALKHTU AlqPOR! LOCAL CLIMATOLOGICAL DATA MEA SVC CONTAAC I ~£1 QSSY lloatlaly Summary Llll IUOE >2° 18 ' • LONGI!u~= 1 S0° 06' II IEftPERATURE °F 0 0 0 I 0 ·TO 0 ·•8 ·10 ·18 ·16 7S 0 ·21 ·12 ·20 ·14 77 0 ·30 ·16• ·24 ·30 81 0 ·12 ·• •U ·I' 71 0 ·12 ·3 ·11 ·18 " 0 11 4 8 0 S7 0 ' ·l 3 ·5 ·12 &2 0 ' ·1 3 ., ·1& 62 0 13 ·10 2 • 7 . ' 63 0 36 13 25 16 11 40 0 H 2S 30 21 20 3S 0 25 11 18 ' l7 47 0 36 13 25 1& 40 0 35 20 28 18 23 31 0 1 2& 21 24 14 14 41 0 28 l ,. 6 7 4' 0 9 ·8 0 ·10 • 8 65 0 11 ·11 0 ·10 • 1 H 0 2S ·14 ' ·5 •• 5' 0 2S I' 22 11 43 0 25 17 31 14 11 43 7 7 &1 4 s 4 5 J EXTREIIE FOR THE HONTH • tAST OCCURRENCE IF IIORE THAN ONE. T TRACE AIIOUNT. • ALSO ON EARLIER OATEISI. HEAVY FOG: VISIBILITY 1/4 IIILE OR LESS. BLANK ENTRIES DENOTE IIISSING OR UNREPORTED DATA. HOURS OF OPS. IIAY BE REDUCED ON A VARIABLE SCHEDULE. ELEVATION IGROUNOI l4S FEET liRE ZONE ALASKAN weAN •26528 26 26 26 26 26 26 25 25 25 25 25 27 28 28 32 32 30 30 30 29 r .01 0 0 0 0 0 0 0 0 . 12 .01 ' . 10 0 DATA IN COLS & AND 12·15 ARE BASED ON 1 OR IIORE OBSERVATIONS AT l·HOUR INTERVALS. RESULTANT WINO IS THE VECTOR SUII OF WINO SPEEDS AND DIRECTIONS DIVIDED BY TilE NUIIBER OF OBSERVATIONS. ONE OF THREE WIND SPEEDS IS GIVEN UNDER FASTEST IIILE: FASTEST IIILE -HIGIIEST RECORDED SPEED FOR WHICH A ftiLE OF MIND PASSES STATION !DIRECTION IN COftPASS POINTS!. FASTEST OBSERVED ONE IIINUTE WIND -HIGHEST ONE IIINUTE SPEED !DIRECTION IN TENS OF DEGREES I. PEAK GUST -HIGIIEST INSTANTANEOUS Wli'4D SPEED !A I APPEARS IN Tllf DIRECIION COLUIINJ. ERRORS WILL BE CORRECTED AND CHANGES IN SUftiiAAT DATA WILL BE ANNOTATED IN THE ANIIUAL PUBLICATION. I CERTIFY THAT THIS IS AN OFFICIAL PUBLICATION OF THE NATIONAL OCEANIC AIIO ArnOSPHERIC ~DniNISTRATIOII, ~NO IS COftPILEO FROH RECORDS ON FILE AT THE NATIOII~l CLIMATIC DATA CENTER, ASHEYILL£. NORTH CAROLINA, 28801 I ~ tloJ_ . llliiGIMI. IIIIIGIMI. •n-. n 0 a a OWIIC.. nti ..... JL Slllli.Jit, 0111 CI.IMIIC 0111 UIIIP ACTING 0 RECTOR · . . "IIOSMliiC IGIII•JSJIIIIOII Ale lllfCIIIIIIIOII SPIJict IIMIILLI-catallll NATIOIIAL CILHATIC DATA CENTER -179- f r: r L l [ [ [_~ L .. rn 1191 ISSN one-uza IAUEETU, ALASU IAU[[IU liRPOAI LOCAL CLIMATOLOGICAL DATA MU SVt COli !RAt I ftE I 08ST Monthly Summary LUIIUOE &2° 1B' ~ L011&11UOE I S0° 0&' W EL[YAIIOI I&ROUIOI 34') r[[l DEGREE Oll5 II[IIN[R IYPES SNOW Itt RIG[ ~I!CO I 5U C01£P ! TEftP[AAfURE °F BASE &~•r ICE PRECIPITITIOI SIUIIJI !ft.P.l! I SUNSMI~E 1 ro& PELLE IS PRmutE 11[~1·;· ! ...... ... 2 H[ln FOG OR ~ II "' ~ [t[l ... )_~I .. "' .... l IHUIOERSTORR ICE 01 ~ ... IICII(S a: ... "' ..... .,._ .,._ ;; ... ... ... ..... c c 4 ICE PELLETS 6ROUIO = ..... ..... ... .. ~ .,. c .,._ .,._ 5 HilL II ELEV. :3; • ~.,. ..... -; -:; ;;; ;; ;; Si a: a: .... ... ::! "' "' ... 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Zli 24 JS IS 21 11 24 38 0 ' ~' .04 .9 ~~.90 ~~ 4.; 4. 8 13 03 10 I 24 i 2S J& 2 , 3 12 4& 0 30 0 0 8. ,3 ~2 4. 1 4. J 12 o2 1 1 u 25 I 26 l7 18 2S 12 n l7 0 30 0 0 ~Ul l& 8.' '· 4 15 02 10 20 27 3S ll 24 8 1& 41 0 29 0 0 ~~·'' 34 4. 2 &.2 12 02 10 27 28 32 12 22 ' 25 43 0 21 . 09 1.1 , . 41 32 1.9 2.1 7 33 10 I 29 iUft ~UR I DIAL IOlAL .vatU or OilS IOUL IOUl lOR IH( llllliiM: I DIAL ; ;u~ SUII ao8 8 llOO 0 46 11 0 11 Ol IP 1&1 IYG. AIG. hG. 0[~. "'-0 DEP. PR[CIPIIIIIOI OEP. ·t· ·t· AI[: 16• JftSihl ... .. AIG. AVG. • a 8 1 18 4 I -12 0 j .01 IIICM. 1 -1.01 ... ; '' IUIIItA OF D.,S S ISDN 10 DUE SIIQI, ICE P[ll[IS GIUIESI II lt NOUAS 110 DAlES GRUI£$1 O[PIH 01 GROUND OF IOIIL IOIIL ) 1.0 IIICH 5 ~UI!!UII I(IIP. 111~111Uft l[ftP 9114 J IHUIIOERSIORIIS 0 PREtiPI 111101 SNOII JC P Ll IS $101, ICE P!LLUS OR ICE 410 OUE ; ,0. • !.1" t }~Qo i J• OEP. OEP. M[AU FOG .I IS ) . 19 ] ,. 0 1~ ~8 I -232 0 Ct.U! 11 PINIU CLOUDY ClOUDY 1\ 1 (HR[ft( roR !M[ IIQIHH • LAS I OCCUAREIICE IF ftOAE THAN ONE. I I RACE ~IIOUNT. • ALSO 0'1 EARLIER OAI[ISI. HEAVI raG: 'II~IB!Lil! 114 ftllE OR LESS. BL'Nc [!IIAIES !lEIIOIE rtl'iSI!IG OR UNAEPOAIEO DATA. IIOURS OF OPS. rtAf 6£ PEOUCEO ON A VARIABLE SCHEDULE. OAIA IN COLS t. AND 12-1c; ARE BASED ON 1 OR rtORE OBSEI'IVAIIONS AT J-HOUR INI[RVALS. RESUL I~NI WINO lS IHE VECTOR SUr! OF WINO SPE£05 AND OIRECIIONS OIYID£0 BY IHE NU"aER Of OBSERVAIIONS !1NE Of IHRE£ WINO SPEEDS I$ GIVEN UNDER FASTEST ftiLE: FASIESf "'ILE • HIGHE'.H RECORDED SPEED fOR IIHICH A rtiLE Of IIINO PASSES STATION IOIRECIION IN CONPASS POINISI. FASTESI OBSERVED 011£ rtiNUIE IIINO -HIGHESI ONE niNUIE SPEED IOIRECIION IN lENS Of DEGREES!. PEAK GU$T • HIGHESI INSUNIANEOUS WINO S~EED !4 1 APPEARS IN IHE OIRECIION 'OLUNNI ERRORS IIILL uE CORRECfED IS !101[: JAN l~P.l ·COL. ~DAILY OAIA COIIPUIED AND CHANGES IN SUftftARY OAIA WILL BE 4NIIOIATED IN !HE ~liNUAl rRo:~ ~~•1-10 '•ORrtALS. n PrJBLtcauoN. I CEAIIFY INAT THIS IS AN OfFICIAL PUBLICATION Of 111[ NAHONAL OCEANIC AIID ATROSPHERIC AOftiNISTRAJION, AND IS COftPILE~ fAOft AECOAOS ON FILE AT TH[ NAIIO!tAl CllftAIIC DAIA CENTER, ASHEVILLE, NDRIH CAROLINA, 28801 I -1?.. 1/J_ ... ,_ ... ,_ ... ,_ 'a n 0 a.· a. Q((MIC... , .. ,_., ... YIQLII(, 0111 CLIMIIC 0111 «••r• ACTING DIRECTOR 11-IIC 11111•1"1111011 .,. lllf-11011 V:II!CC •M•IlU IIGIIIII CIICII.IM IIAHOIIAl Cll"ATIC OAIA CE'IIEA .. , ~AA li8l l1Ll£El~l. lLlSll IALI[t!U AIRPORI LOCAL CLIMATOLOGICAL lloathly Summary [L[liiiQI 1GROUIOI 34S f!£1 DATA DEGR([ QU5 II(UM(R ltPE 5 ! 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