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HomeMy WebLinkAboutSUS245·I I SUSITNA HYDROELECTRIC PROJECT SUSITNA RIVER ICE STUDY 1982-1983 Prepared by: R&M CCNBULTANTS, INC. .... ,...,.._ .. OL.Oet.-ra ...._ ... .._.._ eu.,evo•• TASK 4: ENVIRONMENTAL FINAL DAA~T DECEMBI!R 1983 Prepared tor: SUSITNA JOINT VENTURE '-----ALASKA POWER AUTHORITY ____ , s6/ggl ALASKA POWER AUTHORITY SUSITNA H Y DROELECTRIC PROJECT TASK 4 -ENVIRONMENTAL SUSITNA RIVER ICE STUDY Prepared by: G. Carl Schoch R&M Consultants, Inc. 5024 Cordova Street Anchorage, A l aska 99503 Telephone (907) 561-1733 1982 -1983 December 1983 Prepared for: Harza/Ebasco Joint Venture 7 11 H Street Anchorage , Alaska 99501 Telephone (907) 272-5585 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 B ackground 1.2 Scope of Work for 1982-1983 SUMMARY METEOROLOGY SUSITNA RIVER FREEZE-UP PROCESSES 4. 1 4.2 4.3 Definitions of Ice Terminology c..t~d Comments on Susitna River Ice Frazil Ice Generation Ice Cover Development 4.3.1 Cook Inlet to Chuli tna Confl uen c e 4.3 .2 Chulitna Confluence to Gold Creek 4 .3.3 Gold Creek to Devil Canyon 4.3.4 De vi l Canyon (to Dev il Creek) i Page Ill v vi i xi 1 2 7 11 28 28 31 33 33 39 47 50 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 Pre-Breakup Period 5.2 Breakup Drive 6 . SEDIMENT TRANSPORT 7 . ENVIRONMENTAL E FFECTS 8 . REFERENCES APPENDIX A Monthly Meteorological Summaries from Weather Stations Page 57 58 90 90 92 124 130 134 at Dena l i , Watana , Devil Canyon , Sherman, and Talkeetna 137 APPEND IX B Sus i tna River maps (Aerial Photo Mosaics) from Parks Highway Bridge to Devil Canyon ii 180 s6/gg4 Table Number 1 . 1 LIST OF TABLES Title River Mile Locations of Significant Features on the Susitna River. 3 . 1 Meteorolog:r.al 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 Freez ing Degree Days (°C), September 1980 -May 1981. Susitna River Surface Water Temperature Profile , September 1982 -Octo ber 1982. 4.2 Susitna River at Talkeetna , Freeze-up Obse rv at ions o n the Main stem. 4 .3 Sus i tna R iver at Gold Creek, Freeze-up Observations o n the Mainstem, Octobet· 1982. 4.4 Susitna River at Gold Creek, Freeze-up Obse rvations on the Mainstem , November 1982. iii Page 5 14 17 20 22 60 61 62 63 s 6 /g g5 Table Number LIST OF TABLES (continued) Title 4 . 5 Susitna River at Gold Creek , Freeze-up Observations on the Ma i nstem, Decembe r 1982. 4 .6 Susitna River at Gold Creek , Freeze-up 4 .7 4.8 Observations Observations on the Main s tem , January 1983. 1983 Susitna River Ice Thickness Measurements . River Stages at Freeze-up Measured from Top of Ice Along Banks at Selected Locations. 4.9 Major Annually Recurring Open Leads Between Sunshine RM 83 and Devil Canyon RM 151 Locations and Specifications on March 2 , 1983. 5.1 Water Stage and River Ice Th ick ness Measurements at Selected Mainstem Locations. 5. 2 Susitna Ri ver at Susitna Station Breakup Observations on the Main stem. 5 .3 Susitna River at the Deshka River Confluence Breakup Observations on the Mainstem. 5.4 Susitna River at Gold Creek Breakup Observations on the Mainstem. iv Page 64 65 66 67 68 106 1 11 1 i 2 113 s6/gg6 Figure Number 1 . 1 LIST OF FIGURES Title Susitna Hy droelectric Project Location Map 3.1 Mean Monthly Air Temperatures, September 1982 -May 1983 and H istorical Averages 3 .2 Freezing Degree Days Monthly Totals, September 1982 -May 1983 and Historical Averages 3 .3 Average Historical Accumulated Freezing Degree Days for Susitna River Basin Meteoro logical Stations 3.4 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 Su-sitna River Ice Leading Edge Progression Rates (mile/day) Relative to the Thalweg Profile from River Mile 0 to 155 v Page 6 24 25 26 27 71 72 73 s6/gg7 Figure Number LIST OF FIGURES (co ntinued) Title 4. 4 Stage Fluctu ati ons in Ground Water Well 9 -1 A Rel2tive to Mainstem Discharge. 4 .5 Time lapse Camera Location at Devil Can y on . 5.1 We1 ter Surface Profiles Along 1 ,600 Feet of River Bank Adjacent to Slough 21 Before and During an Ice Jam. v i Page 74 75 114 s6/gg8 Photo Number 4 . 1 LIST OF PHOTOGRAPHS Description Frazil ice clusters 4 .2 Frazil slush floes, S11~itna River at Gold Creek 4 .3 4 .4 4 .5 4.6 4 .7 4.8 October 16 , 1982. Shore ice constriction near Slough 9 , October 26, 1982 . Slush ice accumu lating by juxtapos it io n near Sunshine, October 29, 1982 Border ice growth . Hummocked ice at river mile 103. Ice plume near Slough 9 Anchor ic e dam formed at river mile 140 4. 9 Sediment-laden ice gathered durin g breakup 4.10 river mile 142 Slush ice bridge at ri ve r mile 10 October 26, 1982 . 4.11 Confl uence o f Montana Creek and Susitna River, October 29 , 1982. vii Page 76 76 77 77 78 78 79 79 80 80 81 s6/gg9 Photo Number 4. 12 4 .13 4.14 4 .15 4 .16 4 .17 4 .1 8 4 .19 4 .20 4 .21 4 .22 4.23 LIST OF PHOTOGRAP HS (co ntinued) Description Leading edge of ice cover at river mile 95 , November 2 , 1982. Mai n stem S usitna Rive r adjacent to Talkeetna , Oct ober 30, 1982 . Staging on mainstem Susitna River adjace nt to Talkeetna , November 4, 1982. Su~itna -C hulitna confluence, October 18, 1982. Susitna -Ch ulitna con fluence, Oct ober 29 , 1982. Susitna-Chulitna confluence, November 2 , 1982 Leading edge of ice cover near rive . mile 106 , November 9 , 1982 . Ice cover on Slough 8A , March 14, 1983. Susitna River at Gold Creek , January 13 , 1983. Telescoped ice cover at r1ver mile 106, November 17 , 1982. Open lead at river mile 103.5, Februa r y 2 , 1983. Anchor ice dam at r1ver mile 140 , December 15 , 1982. viii Page 81 82 82 83 83 84 84 85 8 5 86 86 87 s6/gg10 Photo Number 4.24 4 .25 4 .26 4 .27 4 .28 5. 1 5 .2 5 .3 5.4 5.5 5 .6 5 .7 5.8 LIST OF PHOTOGRAPHS (continued) Description Overflow onto bord e r ice caused by anchor ice dam . Time lapse ca mera on south r im o f Dev il Canyon. Ic e bridge i n Devi l Ca n yo n on October 21 , 1982. Ice cover i n Devil Canyon at ri ve r m ile 151 , October 26 , 1982 . Shore ice deve lopment near the confluence with Devil Creek. Open lead enlarging fro m ice fragments , confluence of Deadhorse Creek, Ap ril 28 , 1983 Overflow near P arks Highway Bridge April 7 , 1983 . Ice jam dive r ting flow i nto Slough 11 , May 7 , 1976 . Ic e j am near Montana Creek con flue nce, May 3 , 1983 . Ice jam adjc.cent to Slough 21 , May 4, 1983 . Ice b locks shoved o ver the r iver bank at S lough 2 1 , May 5, 1983 . Ice jam key releas ing a t Slo u gh1 1 , May 6, 1983 . Triangula r ice w edge at S herman , May 6, 1983. ix Page 87 88 88 S9 89 115 115 116 116 1 1 7 117 118 11 8 s6/gg 11 Photv Number 5.9 5.10 5.11 5. 12 5.13 5.14 5.15 LIST OF PHOTOGRAPHS (continued) Description Ice jam near Sherman at river mile 131 .5, May 6 , 1983. Pressure ridge at ice jam near Sherman. Ice jam at Sherman Ice jam at Curry, May 6, 1983. Ice jam at Watana damsite , May 6, 1983 . Ice sheets buckling at Sherman, May 8, 1983. Ice jam, viewed from river mile 102.5, May 9, 1973. 5.16 Ice blocks shoved into fore s t by ice jam at river mile 98 . 5 . 5. 17 Ice debri s piled on r1ver bank at river mile 10 1 .5 5.18 Ice shear wall near river mile 110. 6. 1 Ice floes stranded by Slough 21 after ice drive. 6.2 Si lt depos it from melting ice block. 6.3 Ice scoured r1ver bank. X Page 119 119 120 120 121 121 122 122 123 123 128 128 129 s16/aal ACKNOWLEDGMENTS This study was conducted under contract to Acres American, Inc. until February 1983, and then under cont ract to Harza /Ebasco Join t Venture. Funding was provided by the Alaska Power Authority in conjunction with studies perta ining to the conti nu ing environmental impact assessment for the proposed Susitna Hydroelectric Project . Many individuals participated in the field data col le-:tion efforts during freeze-up and breakup. The logistics involved in documenting over 200 miles of ice cover development were difficult . Consequently, many ice measurements and daily observations were dependent on local residents. The conscientious efforts, ofte n during severe weather conditions, by Butch and Barb Hawley at Susitna Station , Leon Dick at the Deshka River confluen c e, Walt Rice at Talkeetna and Harold and Nancy Larson at Gold Creek are sincerely appreciated. The services provided by Ai r Lo gistics, and particularly the judgement and skill of the pilots , were invaluab le in obtaining ice thicknesses , water velocities and observations of releas i ng ic e jams. The cooperntion 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 Rail r oad. The Arctic En vi ron mental Information and Data (AE I DC) Center provided personnel and equipment to assist in breakup documentation. Special thanks goes to Joe LaBelle for coordinating t~is joint effort . xi s16/aa2 I am especially grateful to Jill Fredston (AEIDC) for assistance in editi ng the preliminary draft of this report. This ice study was dev e loped with the assistance and guidelines of Steve Bredtha uer , senior hydrologist at R&M Consultants, Inc. Steve contributed the majority of the text in Secti on 7 and helped in clarifying several other sections while editing the final draft . The R&M hydrology staff prov ided assistance with field measurements and much us efu l information fro m occasio nal aerial observation s. In addi ti on , the extraordi- nary patience of the typing staff and their efforts towards a timely com - pletion are si ncerely appreciated . xii s16/w1 1.0 INTRODUCTION The study of ice on the Susitna River has been ongo1ng since the winter of 1980-1981 . Prior to this report , the documentation had been restricted to obliqu e aerial photography and intermittent observations by field crews. Initially, the intent was to target locations of specific ice processes such as frazil ice generation , shore ice const r i ctions, ice bridges, and ice jams. Much qualitative informatio n was gathered and documented in the Ice Observations Reports (R&M 1981b , 1982d). Renewed emphasis by en vi ron mental concerns on potential modificat io ns to the river ice regime by hydroelectric power deve lopment resulted in a more refined ice program for 1982-1983 directed towards specific problems which may be unique to hydropower development on t he Susitna River . Staging, ice cove r 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 scope of the current study to mathematically analyze the specific mechan ic s of river ice processes. Instead, the objective is to describe the phenomena based on field observations and measurements. 1. 1 Background Ice thickness data has been collected at surveyed cross-sections since the winter of 1980-81, and used to compile a profile of the Susitna River ice cover downstream of the proposed Watana damsite. Additional h ,sto r ical data on ice thicknesses are available from the U.S . Geological Survey (USGS). This agei}CY maintains several s tream gaging sites on the Susitna River, most o f which are visi ted during the winter to obta in under-ice discharges. Upper Susitna data records begin in 1950 for Gold Creek ~nd 1962 for the Cantwell si te . Bilello of the U.S. Army Cold Regions Research and Engineering Laboratory (CRR EL) conducted a comprehensi ve study entitled, "A Winter Environmental Data Survey of the Drainage Basin of the Upper Susitna River, Alaska" (1980). This report summarizes s16/w2 monthly ice thickness measurements from 1961 to 1967 at Talkeetna and from 1967 to 1970 near Trapper's Creek. Data concerning o ther aspec~s of the ice regi me on the Susitna are scarce . The best potential s o urce for a variety of qualitative historical information concerning ice jams and floods are area re- sidents , especially those employed by the Alaska Railroad. Ma ny interviews were conducted , with the resulting informatio n documented in the 1981 ice repor·t ( R&M 1981 b). This first ice repo r t primarily consisted of narrative chronological descriptions based on aerial observations at various sites. The report also contains most of the historical informat ion available from the U .S . Geological Survey, the National Weather Service River Forecast Center, and the U.S. Army, Corp of Engineers . The 1981-1982 ice study followed the same general guidelines. Aerial reconnaissance was conducted weekly through January , with the freeze-up sequence of October through December described in the final report (R&M 1982d). Ice thickness measurements were obtained at many of the locations surveyed in 1981 i n orde r to assess year-to-year variabili ty . Breakup was periodically observed from April 12 to May 15 , with documentation limited to in formation 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 o n documenting site specific, ice cover induced problems identified during p-evious observations. These included ice jamming and flooding at the Susitnc. confluence with the east channel of the Chulitna River, staging effects thro u gh spawning areas, and ice jamming near the proposed upstream cofferdam at Watana. Reaches where ice jams recur annually were investigated for 2 s16/w3 morphologic changes and for identificat io n o f c r it ical factors gove rn 1ng ice j am formation . Collec tion o f add iti o nal quantitativ e data was a ls o required for pro p osed modell i ng effo rts . These data i n c luded v e- locities , maximum stages at v a r io us sites , ice thi ck nesses , ice d is- charges , rates of ice cover ad v ance , water temperatures , and loca- tions of s ignif icant open lea ds . The number of observ ations was i n creased i n proportio n to the freq uency o 1 specific ice e v ents. During breakup , f ield crews documented da ilv changes i n the ice cover . The specific data collected during the 1982-1983 season in- cluded: 1 . Locat ions of ice bridges 2 . Rate o f upstream pro gression of the ice cover 3 . Ice discharge estimates 4 . Ice cover at tributari es 5 . Ice cover at aquat ic habitat ar e as 6. Water temperature 7. Locations and size of open leads 8 . Aerial photography , obl ique and v ert1cal Meteorological data at speci fic sites 10. lr:e cover processes i n Devil Ca n yo n 11 . Max imum water levels 12. Ice thicknesses 13. Velocities and discharges 14. Profiles and c t~oss sections 15. Time-lapse photography 16 . Locati o ns and effects of ice jams 17. Water table fluctuations Meteoro logical data from five weather stations near the river channel are summari zed in Section 3. In addition , figures are provided that illustrate the v ariability in a i r temperatures, freezing degree-days and precip i tation between the upper Susitna at Denali and Talkeetna. 3 s 16 /w4 Section 4 considers the processes associated with ice cover develop- ment and how they relate to the 1982 Susitna River freeze-up . The processes of frazil ice formation, ice cover progression by jux taposi tion and staging, shore ice development , and effects on the water table are described. Breakup is described in Section 5 , be- ginning with the initial processes of ice deterioration followed by the cause and effects of ice jams. The processes of sediment transport during freeze-up are described in Section 6 , along with the mo re 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 modificati o ns 3. Relationship between sloughs and ice jams 4. Damage to vegetation 5. Ice regime in side channels and sloughs 6. Flooding o f islands Photograph s illustrating specific ice processes and events have been included in order to assist in understanding the characteristics and effects of the Susitna River ice regime . Many of the discussions 1n this report rely on a familiarity with certain place names and river mile locations . Table 1 .1 lists those which are significant for this report . Figure 1 .1 shows the Susitna Hydroelectric Project location relative to southcentral Alaska. River mile locations have been annotated 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 * sG/1 1 TABLE 1 .1 RIVER MILE L OCATIONS OF SIGNIFICANT FEATURES O N THE S USITNA RI V ER Place Mo uth o f Devil Ca nyo n Portage Creek Slough 22 Slo ugh 21 In dian Rtver Gold Creek Slough 11 Sherman Slough 9 Slough 8 Slough 7 Curry Lane Creek Chase Whiskers Creek Chulitna/Susitna Confi!Jence Talkeetna Head of B i rch Slough Sunshine/Parks Highwa y Bridge Rab ideu x Creek Montana Creek Goose Creek Slough Kashwitna Creek Wil l ow Creek Desh ka River Yentna River Susitna Station Alexander Slough Alexander Ri ve r Mile * 150.0 149.0 144 .5 142 .0 133 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 mosa1 c maps ind ica ting rtver miles are included in Appendix B . Locations i n dicate the mo st upstrl:!am and o r entrance unless o the r·wise noted . - 5 - ! LOCATION MAP PRINCe SOU NO 20 0 20 60 SCA LE I N MILES SUSITNA HYDROELECTRIC PROJECT LOCATION MAP Figure 1.1 ;:::l&M COI\lSULTANTS, I NC. •NO tN.eR W OeOt..."'lOI»'T& Pt..ANN8R8 ~UQV.VO R~ SUS/TNA JOINT VENTU RE 6 s 16/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 1982, most of the rive r wate r had cooled to 0°C and f1 ·azil slush had accumulated i nto an ice cover that started near Cook Inlet and extended upstream to Talkeetna. The development of an ice cover on the lower river from 10 miles above Cook Inlet up to Talkeetna required about 14 days. This rapid ice cov er progression was due primarily to the cold air temperatures , gentle gradi- ent , and a long open water reach o n the upper river for frazil generation. Ve ry little staging was necessary during the ice cover advance , with level s of 2-3 feet upstream to approximately r1ver mile (R M) 67 , then steadily increasing as the channel gradient becamE' steeper . At Talkeetna the staging amount ed to over 4 f eet near the entrance to a side channel . On November 2 , 1982, an ice bridge formed 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 aiong this reach was generally more extreme than downstream of Talkeetna, with water levels often rising more than 6 feet. The leading edge reached Gold Creek by January 14 , 1983, after having slowed to a progression rate of 300 feet/day. The slower ice cover progression was due to tl">e steeper gradient and a reduction in the frazil ice generation, caused by the development of a continuous ice cover on the upper river above Watana. This effectively sealed off the air/water interface preventing heat exchange and frazil generation. The reach from Gold Creek ( RM 136) to Devil Canyon (RM 150) took even longer to freeze than the downstream reaches. The rrocesses involved were different from those in the reaches further downstream, as this area experienced extensive shore ice development and anchor ice dams. A time lapse came ra was mounted on the south rim of Devil Canyon in order to document the formation of massive ice shelves that develop near 7 s 1 G/v2 the proposed dams ite . The slush ice cov er i n this turbulent , high velocity reach, o ften the first to form o n the entire Susitna River , was v ery unstable , constantly either disintegrating or accu mu lat 1ng. T he 8 mm movie camera provided footage that reveal e d vaiJable informa tion concern- i ng how an ice cover forms over rap ids . The upper nver from Devil Ca n yon to Dena li was not mon1tored closely during freeze-up o r b reakup , but rout ine flights t o Watana Camp prov ided qualitative i nformatio n o n the processes affectir.g this reach. This reach dev elops w ide sh o re ice by building successive la yers o f frazi l and snow slush. The channel finally becomes so narro w that flow1ng slush is en- trapped, eventually freezing i nto a co ntinu o us ice cover . After an initial ice cove r forms, continually decreasing water levels lower the floating ice until the majority of the cover has grounded . Open leads develop over turbulent water , b ut may eventually close again throu ;h accumulations of fine slush ice against the downstream edge o f the lead. Many open leads pers1st all winter along the entire length o f the r iver. Several isolated groundwate• seeps ha v e been identified i n the ma i nstem , side channels and sloughs . These can erode away the existing ice cover. These areas often remain ice -free f ,...~ most of t h e winter. Breakup processes on the Susitna River are similar to those described for ot her northern rivers , with a pre -breakup period , a drive , and a wash (Mich el , 1971). The pre-breakup period occurs as s n owmelt begins due to increased solar radiation in early April . This p rocess generally begins .l t th~ lower elevations near the mouth of the Susitna River , working its way north . By late April , the snow has generally disappeared from t he r1ver south of Talkeetna and has started to melt along the river above Talkeetna. Snow o n the ri ve r ice genera ll y dis ap pears before that along the banks , either due to overflow or because the snowpack is simply thinner on the r ive r due to exposure to winds. As t he river discharge increases, the ice cover begins to lift , causing fractures at variotJS points. 8 s16/v3 On the Susitna River , long , narrow leads beg in to form . Small jams of fragmented ice f o rm at the downstream ends against the solid ice cover. These ice jams often resemble a U-or V -shaped wed g e . wrth the apeY of the wedge corresponding to the highest velocities in the flow di ~tr ibu tion The constant pressure exerted by these wedge-shaped ice jam e ffectivel y lengthens and widens man y open leads , reducing the potential f o r majo • jams est these points. The drive , or the act:ual downstream breakup of the ice cover , occur s when the discharge is high enough to break dnd move the ice sheet. T h e i ntensity and duration is dependent on mPteorological conditions during th e pre-breakup period. Both weak and strong ice drives have 1--,een obserVE!d on the Susitna River during the last 3 years. Jam sites generally have similar channel c o nfigurations , ronsisting of a broad chan nel with gravel islands or bars, and a narrow, deep thalweg co nf i n ed alo ng one of the banks . Sharp bends in the ri v er are aho potential jam sites. The presence of sloughs on a ri ver reach may indicat e the locations of frequently recurring ice jams . During breakup, ice jarr s commonly cause rapid , local stage increases that co ntinue rrsrng until either the jam releases or the sloughs are flooded. Whil e the jam holds, channel capacity is greatly red uced , and flow is diverted into the trees and side-channels, carrying large amounts o f ice. The ice has tremendou~; erosive force, and can rap idly remove large sections of bank. Old ice· scars up to 10 feet above the bank level have been noted along s ide- channels. Stabl e ice ja ms are sometimes crea ted when massrve ice sheets snap loose from shore-fast ice and pivot out into the mainstem flow. In May of 198_, an extensive buildup of flowing ice debris was sto pped near RM 101 .5 by a comb inati on o f the only remaining solid ice cover , and a shallow reach of rrver nearly 3 miles long. The ice cover disintegrated o n impact but stalled the flow lo ng enough for the ice to prle up and ground fast . This jam held for two days . Once this jam broke up , the ice deb.·is flowed unobstructed to Cook Inlet . Alt ho ugh by May 10 , 1983 , the entire 9 s 16/v4 river was essentially ice-free, ice floes con t i:-.•Jed drrfting downstream for several weeks as previously stranded flo\o\ s were picked up by steadily increasi ng discharges. The lower Susitna R iver downstream o f T Jl keetna experienced a mild breakup in 1983. Observers at the Oeshka Riv~r confluence and at Susitna Station thoroughly documented breakup. ""!"heir descriptions and data irr dicated that the ice cover fragment ~,d and flowed out between May 2 and May 4. Most of the ice cover simply deteriorated while rc:naining shore-fast, with little jamming activity taking place. The only signif ica nt ice jam observed below the Parks Highway Bridge occurred near the con flu- ence with Montana Creek. I his past rrver ice season was significantly influenced by mild temper- atures and heavy snowfall. Ice thicknesse:; did not reach proportions of previous years , and little precipitat io n occurred during breakup. Much data was documented during freeze -u p i n 1982 and breakup in 1983 for computer modelling input , bu t it must be recognized that the data may not necessarily represent conditions in a normal yea r . 10 sG /hh 1 3.0 METEOROLOGY Mathematical derivations of heat exchange coefficients will be required for compute r simulations of river ice cover formation. Accurate and consistent measurements of meteorological 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 Hydro electric Project. Natural water bodies receive the most heat from solar shortwave radiation ( H ) and longwave atmospher ic radiation ( H ) , and lose heat to the atmo-s a sphere by longwave back radiation ( H b), ev aporation heat loss (He), and conduction heat loss (H ) . Not all of the incom1ng solar and long wave c radiation is absorbed, with a certain percentage reflected at the water surface. Ref la~ted solar radiation (H ) is usually of greater magnitude sr than reflected atmospher ic radiation (H ) , but is more vanable due to ar cloud cover, latitude, and altitude. The net rate of heat transfer across a water surface is: H = (H s H • H sr a H ) -(Hb! H :t H). ar c e The parameters representing the absorbed radiation , combined in the parentheses on the left, are i ndependent of the wate1· surface temperature . The terms i n the r·ight parentheses represent the temperature dependent parameters of heat loss (Edinger, 1974). Values for the individua l heat exchange <...omponents <..an be derived from the following measured meteorolog ical variables: solar radiation , air temper- ature, and dew poin t temperature. These parameters have been monitored 11 s6/hh2 at s e v eral locations throughout the upper Susitna Basin for the past 3 y ears by R&M Consultants . In addition, a 42 -year record is available from the meteorolog ical station at th e Tal keetna Airport operated by the National Weat her Serv ic e . These weather stations were selected for inclusion in t his report because they prov ide the best available data to estimate the climatic regime directl y influencing the water su rface . They are located at Dena li, Wa tana , Devil Canyon, Sherman , and Talkeetna . Addi tional info r- mation z bout each weather statio n, including axac:t location and senso r specifications, have been published previo usly and is not included in th is report. Those readers not fanriliar with t~is aspect of the project may wish t0 consu lt the Processed Climatic Data Repo rts , Vo l umes 1-8 ( R&M , 1982e), wh ich i n cl u ri e a detailed description of the meteorological d a ta col lection progra'Tl. Mean max imu m, mea n m1n1mum and mea n daily air temperatures fo r e ach station from Sept~mber 1982 through May 1983 have been summarized in Table 3.1. Mean dail y air temperatures are plotted i n Figure 3. 1 . Tables 3.2, 3.3, and 3.4 l ist the number of freez i ng degree -da ys per month between September an d May fo r the existing record at each sta tion (Talkeet- na 1980-1983 on l y), and are g raphed i n Figure 3 .2. On ly the Watana (R&M Consultants) and Talkeetna (NWS) stations ha v e the capa b il ity to measure precipitation on a daily basis throughout the winter months . These data ha ve been p lotted i n Figure 3.3. The meteorology within the upper Susitna Bas i n is h igh ly variable at any given time between weather station sites . This is due, i n part , to the movement of storm sys tems , the topographic variance , and the change in latitude, but mostly to the 2,400-foot difference in elevation between Denali and Talkeetna. The graphs presented in this section i llustrate not o nly the colder dail y temperatures at Denali , but also their longer duration. For instance, 1n October 1982 Denali had a t ota l o f approxi mately 3 70 freez ing degree-days (°C) while Talkeetna had o nly 170 . This difference may be significant , since the entire Susitna River downs ~ream o f Talkeetna developed an ice cove r by November 1 , 1982 . Caution is therefore advised 12 s6/hh3 in using average values of freezing degree-days for the entire Susitna Basin, since these may not be representative of all locations 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 due to orographic effects at Watana and to 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 meteorolo~ical summanes from each respective weather station . These have been included 'r, Appendix A. 13 1-' ""' -- --Mean Mn -..:imt lm _(~ ~mb er 12§? IHikeetnH 11.5 Sl1 e rman 11.4 Ocvi I Canyon 9.'l W<1 tana 8.4 Dona I 1" - - Bas 1 n Ave rage 10.2 ra I keetna -0.6 S he rm11n• I . 0 Devi 1 Canyon -2 .6 Watana -3.3 Dena 1 1 - - Bas1n Aver11ge -1.4 November 1 ~ rdlkeetna -II. 4 St1 erman* -Lt. 5 DtJVI I Canyon -'>. 8 Wa lilna -7. 1 Dena 1 1 • - ----------·- Basin Average 5.5 lABL ( 3.1 MElE OROlOG ICAL DATA SU MMAR " FRO M Sl LI CT[O WlAT H[R STATIONS ALONG THE UPPER SUSITNA RIVER SEPTE MB ER 1982 -MAY 1983 Air Tempe r..2..t.l!r·es ~le11n M~an Oepa rture M1n1mllm Monthly from Norma 1 Prec 1 p 1 ta t1 on ~J -( °C l ( °C l (nun l ILl I. 8 0.0 190.0 2.8 7. 1 0.0 232.2 2.5 6.0 1 .11 156.6 1.6 5.0 0 ·'' 100 .8 -3.6 -0.? 2.8 5.9 0 . .3 169.9 -9. ,, -5.0 -4.9 52.2 -8.() -5.7 0 .0 -9.8 -6.2 -11. I -11.9 -I. 6 -3.8 ''· 2 --11.8 -6.0 - -9.8 -1 .3 -3.8 28.2 -12.6 -8.5 -0.4 42.8 -11. ,, -Hl.O IJ.Il -11.9 -8.9 -1. 5 -111. 4 -1(). 7 -1. It 0.2 --15.7 -5 .2 ----- -1 2.6 -10.8 - 1 . 7 2 1 .5 O~pa rture from Normal lmm 76. 1 0.0 ?9. 1 15.6 3 7. I -11.8 -6. 1 -9.0 -2 .3 -2. ,, -2. ,, Depth of Snow on Ground e m 0.0 0.0 LtO. 3 IU. 6 * Partial Record-Some va lttes ror mean dail y temp eratu r es, u se d to compute the mean monthly temperature, are based on 1 •near ruyre~s•on analyse~. See AppendiA A. -S~/C02 TABLf 3.1 (Contonued ) ______ P..• r Temperatures Mean Mean Mean Depar ture-Departure Oep t.h of Snow Maxomum Monimum Nunthly from Normal P rec i p ' ta to on from Norma 1 on Gro untl -~ ( oc ) '°C l '°C l (mm) (mml __icm l DO £~m..QQL ~ Talkeetna -3.5 -10.8 -1.2 ~.6 4,,11 ?.3 73 0 1 Sherman -4.11 -1 2.7 -8.7 0.1) Oev i 1 Canyon -~ 0 1 -1 1 0 3 -8.2 11,11 Wat.ana -6 .9 -13.9 -10.11 IL 7 7.0 2.3 Dena 1 i * -9.6 -19.6 -15.4 11.8 ---- Bas on Average -6.0 -13.7 -10.0 L9 26 .2 2.3 JnnLodr~ 128J l a l k(;etna -6.2 -15,14 -10.8 ;>, l 11.6 -24.9 80 .6 Sh erman* -8.6 -17 .4 - 1 1 0 t) IJ.O --- Oev 1 I Ganyo11* -8.5 -15.4 - 1 1 0 II - 1 0 '; --93.? Watana -11 0 0 -17 0 I I -111 . 1 -1 0 ;> 2.8 1 0 3 26.2 ..... Dena 1 '* -12 0 1 -22.0 -17 0 1 -1 0 "I --20.9 lJl -------·-- Basin Average -9.3 -17.5 -12.9 -0.3 7.2 -11 0 8 55.2 feb nw r':L. J.!l.!U. Ia 1 keetna -1. I -13 0 3 -I .'.> ?.3 11.6 -~I. U 80.6 Shern.an* -9 0 1 -21 0 ~ -8.0 O.(J --107.9 Ccvi 1 canyon -3 0 2 -1 1.9 -7.5 1.5 --93.2 wa tana -6 .5 -13.6 -10.0 -2.5 0.0 -15.2 29.0 De n a 1 i -8.9 -1 9.3 -1 11 , 1 0. 7 --25.7 ----- Basi n Average -5.9 -15.9 -9,14 0.4 5.8 -2 1 0 1 67.3 * Pao t oa l Hecord-Some values for mea n cJao l y temperatures, u se d to compute t h e mean monthly tempera t u re , are bas ed on 1 iroear reyressoon anu l yses. 51;!t: AppcncJox A. TABLE 3 .1 (Cant t nued l Air Te mperatures Me an Mea n Mea n Depa rt-u;:e Departure Depth of Snow Maxi mum Min i mum Mont hl y from Norma 1 P rec i pi tali on from Norma I on Ground I 0 Cl I °Cl I 0 Cl '°C l 1mm) 1mm) I e m Marc h ~ 1 a 1 k ee 1 na 3. I -10 .7 -3.~ 3 .6 2.3 -35.3 75.6 Sh erman* 6.1 -11.2 -11.2 0 .0 --106.8 Devi 1 Canyon 0. I -10 .5 -11.9 -0.3 --96.3 Wa tana -3 .3 -1 2 .0 -7.6 -0 .9 --- Dena 1 i -5.3 -18 .2 -11 .8 -2.2 --31.8 Bas i n Avera9e 1. 9 -1 2.~ -6.4 0.0 2 .3 -3~.3 78.9 Aori I 1.ill 1a lkee tna 6.9 -·L 1 1.9 1 .II 6~.0 30. I 55.4 Sh e rman 8.0 -II . I I 1.8 0.1) 68.0 0.0 - Oev i 1 Canyon 5.6 -4 .0 0.8 ll.4 33.2 -92 .0 wa tana 3 .2 -5 .I~ -1 . 1 2.2 2 .6 -2 1.7 f-' (1\ Dena 1 i 3 . 0 -7.6 -2.3 2.'> 0.8 -33.5 Basin Average 5. 3 -4.9 0.2 1 . 3 33.9 -50 .7 May 1983 Talkee tna 111 . 'I 3.1l 9. 1 3. I I 32.:1 -3. 1 n.o Sh e rman 12. I o. 1 6.9 ().I ) 19.11 0.0 0.0 Dcvi I Ca nyon 11.9 1 .8 6.8 0.2 25.11 -0 .0 Wa La n a 9.9 0.6 5.3 0.2 15.2 -0.0 Dena 1 i 9.1 0 .11 4 .9 0.1 7.6 -0.0 Basin Avsrag e 11. 7 1 . 2 6.6 0.8 20.0 -0.0 .. Pa r ti a l l<eco nJ-Som e value:. fur me an duily t e mpl:lrature s, used to compute the mean mun UH y tt!tnl)c ratu re , aru tw:.ed o n li near reg re ss t o n ana l yses. See Appendi x A . s5/hh 1 Se~te mber 1982 Talkeetna Sherman Devil Ca n yon Watana Denali* Basin Average October 1982 Talkeetna Sherman* Devil Canyon Watana Denali* Basin A verage Nov ember 1982 Talkeetna S herman* De v il Ca n yo n Watana Denali* Basi n Average TABLE 3.2 NUMB ER OF FREEZING DEGREE DAYS (°C) September 1982 -May 1983 Average Historical** Mon thl:i Accu mulated Mon thl:i 0 0 0 0 0 0 0 0 5 1 1 13 7 7 17 2 2 7 172 172 72 189 189 200 200 95 236 237 127 367 374 192 233 234 122 258 430 191 301 490 256 456 222 304 541 279 471 845 376 318 552 267 17 Mean Monthly Air Temperature (°C) 7 .8 7 .1 6.0 5 .0 3 .6 5.9 -5 .0 -5.7 -6 .2 -7 .6 -11 . 8 -7 .3 -8 .5 -10.0 -8.9 -10 .7 -15 .7 -10.8 s5/hh2 December 1982 Talkeetna Sherman Devil Canyon Watana Denali* Bas in Average Januar~ 1983 Talkeetna Sherman* Dev i l Canyon* Watana Denali* Basin Average Februar~ 198.1 Talkeetna Sherman* Dev i l Canyo n Watana Denal i Basin Average TABLE 3 .2 NU MBER OF FREEZING DEGREE DAYS (°C) September 1982 -May 1983 (Continued) Average His t o rical** Month I ~ Accumulated Month I ~ 230 660 407 274 764 255 71 1 391 324 865 468 477 1322 627 3 12 864 473 336 996 311 340 11 04 354 1065 325 440 1305 402 630 1952 53 1 420 1284 392 ~11 1207 224 225 1329 212 1277 254 281 1 586 289 395 2347 416 265 1549 297 18 Mean Monthly Ai r Temperature (oC) -7 .2 -8 .7 -8 .2 -10.4 -1 5.4 -10 .0 -10 .8 -11 . 0 -11 . 4 -14 . 1 -17. 1 -1 2 .9 -7 .5 -8.0 -7.5 -10.0 -14 . 1 -9 .4 s5/hh3 March 1983 T alkeetna S herman* Devil Ca nyo n Watana Dena I; Basin Average Aeril 1983 Talkeetna Sherman Devil Ca n yon Watana Denali Basin Average Ma):: 1983 Talkeetna Sherman Devil Ca n yon Watana Denali Basi n Average T ABLE 3 .2 NUMBER OF FREEZING DEGREE DAYS (°C) Se ptembe r 1982 -May 1983 (Continued) Ave rage Historical** Month I):: Accu mu Ia ted Mo nth 120 1327 107 128 1455 153 1430 147 233 1819 223 366 27 13 302 200 1749 195 15 1342 36 2 1 1476 21 30 1460 75 65 1884 115 81 2794 151 42 1791 80 0 1342 0 0 1476 0 0 1460 0 0 1884 9 0 2794 5 0 1791 3 Mean Mon thl y A i r Temperature (°C) -3 .5 -4 .2 -4.9 -7.6 -11 . 8 -6.4 1. 9 1.8 0.8 -1 . 1 -2.3 0 .2 9 . 1 6 .9 6 .8 5.3 4.9 6.6 * Partial Record -Some values are based on linear regre s sion analyses . See Appendi x A. ** Period of Record: Talkeetna Sherman Devil Canyon V/atana Denali 1940-1983 , only used 1980-1983 1982 -1983 1980 -1983 1980 -1983 1980 -1983 19 s S/c cS TABLE 3 .3 NUMBER OF FREEZING DEGREE D A YS (°C) SEPTEMBER 198 1 -May 1982 Mean Monthly Air Temperature Monthly Accumulated (oC) Se~tember 1981 Ta lkeetna 0 0 7 .3 Sherman (No Data) Devil Canyon 12 12 4 .4 Watana 33 33 4 .0 Denali 40 40 3 .2 Bas i n 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 Denal i 108 148 -2.8 Basi n Average 63 84 -0.8 November 1981 Talkeetna 205 234 -6.4 Sherman (No Data) Devil C anyon 255 308 -8 .3 Watan a 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) Devil Ca n yon 363 67 1 -11 . 6 Watana 424 845 -13.7 Denali 514 1051 -1 6.5 Basin Average 417 792 -13.4 Janu ary 1982 Talkeetna 53 1 1 132 -17. 1 Sherman (No Data) Devil Canyon 52 8 1199 -17 .0 Watana 622 1467 -20. 1 Denali 782 1833 -25 .2 Basin A v erage 616 1408 -19.8 20 s5/cc6 TABLE 3.3 NUMBER OF FREEZING DEGREE DAYS (°C) S EPTEMBER 1981 -May 1982 (Continued) Mean Monthly Air Temperature MonthlY: Accumulated (°C) FebruarY: 1982 Talkeetna 285 1417 -9 .9 S herman (No Data ) Devil Canyon 344 1543 -12 . 1 Watana 365 1782 -13.0 Denali 525 2358 -18.7 Basin Average 380 1775 -10.7 March 1982 Talkeetna 161 1578 -5 .0 Sherman (No Data) Devil Canyon 223 1766 -7. 1 Watana 299 208 1 -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 Avera£'.,. 11 8 2153 -3 .3 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 Basin Average 8.4 2164 4 .4 21 s5/cc7 TABLE 3 .4 NUMBER OF FREEZING DEGREE DAYS (o C) SEPTEMBER 1980 -MAY 1981 Mean Monthly Air Temperature Month I ):: Accumulated (°C) Seetember 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 Ca n yon 45 46 0.2 Watana 74 78 -2 . 1 Denali 102 106 -2 .9 Bas i n Average 59 61 -0.7 November 1980 Talkeetna 111 125 -3.5 Devil Canyon 154 279 -5. 1 Watana 216 29 4 -7 .2 Denali 269 375 -9.0 Bas i n Average 188 268 -6 .2 December 1980 Ta l keetna 623 748 -20 . 1 Devil Canyon 556 835 -17.9 \Vatana 656 950 -21 . 1 Dena li 890 1265 -28.8 Basin Average 681 950 -22 .0 22 s5/cc8 TABLE 3 .4 NUMBER OF FREEZING DEGREE DAYS (°C) SEPTEMBER 1980 -MAY 1981 (Continued) Mean Monthly Air Temperature Monthly Accumulated (oC) January 1981 Talkeetna 66 814 -1 . 8 Devil Canyon 9 2 927 -2.5 Watana 143 1070 -4.5 Denali 181 1446 -5.5 Basin Average 121 1064 -3.6 February 1981 Talkeetna 177 991 -6. 1 Devi l Canyon 205 1132 -7 .3 Watan a 221 1291 -7.9 Denali 328 1774 -11 . 8 Basin Average 233 1297 -8.3 March 1981 Talkeetna 40 1031 -0.4 Devil Canyon 65 1197 -1.8 Watana 136 1427 -4.3 Denali 181 1955 -5.6 Basin A v erage 10 6 1403 -3.0 April 1981 Talkeetna 48 1079 -0. 1 Dev i l Canyon 92 1289 -1.8 Watana 141 1568 -4.3 Denali 190 2145 -6.2 Basin Average 118 1520 -3. 1 May 1981 Talkeetna 0 10 79 10 .0 Devil Canyon 0 1289 8 .7 Watana 0 1568 7.6 Denali 0 2145 7. 1 Basin Average 0 1520 8.4 23 a O ~0 a2 ~(I) ~c ~~ ~~ ~2 :,.. ~m cw ·-:z ~n .. I "" , -co c ... G C,t) ..,\ ~~ ~ ~ ~~ :b. -(.L: C5 ll ~~ ~~ ~~ ~~ ~~ "'(§ 0 ~ w a: ::l ... "' a: w ~ :i w ... !: "' MEAN MONTHLY AIR TEMPERATURE SEPTEMBER 1982-MAY 1983 AND HISTORIC MEAN 0 ~ w a: ::l ... "' a: w ~ :i w ... a: < 10 0 -10 -20 10 0 -10 -20 '/" --1882-83 tlletotlcal a vetege, 1840-1883 -3o I I I I I I I I I MONTH Location: T a lkeetna Aluka Operator: National Weather Service 10 ... 0 2.. 0 w a: ::l ... 4( -10 a: w ~ :IE -1882 -83 w -20t ... --Netorkel 1 \ena•. a: 1110-U ~ ... 0 ~ w a: ::l ... 10 0 "' a: -10 w ~ :IE w ... -20 !: "' --· uu-u (no hletotlc: rec:otd) -3o I I I I I I I I I I -1812-U --hlltOik:IJ I VIflgl, 1110-11 MONTH Location: Sherman Weather Station Operator: R & M Consultants, Inc. ... 0 ~ w a: ::l ... 10 : -10 w ~ :1 w ... -20 a: ~ hl etcwk al •••r•;•. 1110-U -3o I I I I I I I I I I -2o I I I I I I I I I I -2o I I I I I I I I I I MONTH Loc a tion: Devil Canyon Weather Station Operator: R & M Consultanla, Inc:. MONTH Location: Watana Weather Station Operator: R & M Conaultanta. Inc. MONTH Location: Denali Weather Station Operator: R & M Consultant., Inc. aO ~0 ii 2 ~(I) ~c ~~ n> ~2 L.f ~ln c~ • <-:2 gn .. N VI -n -· co c .. CD (,.) • ~ ~-~ )l> ~ ' CJ 11 ~IR!t "'i~ ~~ ~~ §~ fll(§ FREEZING DEGREE DAYS MONT H LY TOTAL (/) > <t 4 00 0 0 e... 300 w w a: 200 " w 0 100 (/) > 000 <t 0 ~ 400 ttl 300· a: " w 200 0 " z 100 N w ~ ol ll'!lll'!llmll'i''lm 'llll llrrlll I MONTH location: Talkeetna, Alaek a Operator: National Weather Se rv i ce (/) )o 500 ~ c 0 400 ~ w w a: " w c " 300 1 00 z 100 N 1!!11 D 1982 -83 H I STORICAL AVERAGE (/) )o <t 0 400 0 't. ~00 w w a: " w 0 100 <-' !QO z N o +---~~~-4~-+~~~~~~~+-~ ttl SEP a: MONTH II. location: Sharman Weather Station Operator: R & M Con tultantt, Inc. 700 (/) > 1 00 ~ 0 0 100 ~ w w a: " w c " 400 100 · ! 100 N w w f 100 " z ~ o I ., I n I I 1'1 ljl!l II l!t I I';' ' I e:ll I m ! I I w w a: II. '~ ol-nllillllll ll lil ll lli!IIYI I mllrnll al BEP OCT NOV OEC JA N fEI MAll APII MAY o~~~~~LL~~~~~~~~~~~~ MONTH w a: II. MONTH location: Devil Canyon Weather Statton Op:rat!lr : R & M Contultante, Inc. MONTH location: Watana Weather S tation Ope rator: R & M C on eultanh, Inc:. Location: Dena li W e ather Station Operator: R a M C oneultanh , Inc. (/) > «:(2000 Q w w a: e w Q e z N w w 1000 a: "" 500 O SEP AVERAGE HISTORICAL ACCUMULATED FREEZING DEGREE DAYS FOR SUSITNA RIVER BASIN OCT METEOROLOGICAL STATIONS 1980-1983 NOV DEC JAN MONTH FEB MAR APR =================================================~ Fi g ure 3 .3 . ~~[Effj~~~® 26 SUS/TNA JOINT VEN TU RE R&M CONSUL.TANTS, INC. aNUINa.AS OCC\.CGISTa P'\.ANN.aa SUA V • ..,OIIIS -E E - -E E -z 0 -t-<t t--Q. -(J w ~ Q. 400 MONTHLY PRECIPITATION DATA October 198 2 -May 1983 mEl precipitation water equivalent 0 precipitation anowfall cs;:J maximum snow depth on ground Location: Watana Weather Station ., Operator: R & M Consultants, Inc. 800 800 400 200 Location: Talkeetna, Alaska Operator: National Weather Service Figure 3.4 R&M CCNSULTANTS1 INC. .NOtNae~~~t• CICO~ SteT• •LANN··· •u•vevo•e 2 7 SUSITNA JOINT VENTURE s6/ii1 4.0 SUSITNA RIVER FREEZE -U P 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 dams ite 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 terminolo- gy used in describing river ice and since a rather extensive descrip- tion of ice processes o n the Sus itna River follows , a brief discussion on common types of ice observed on the S usitna is presented here. This is not intended to be a complete glossary of ice terms, and those in terested in information on oth er types of ice should refer to the more defin itive papers o n river ice listed in Section 8 (e .g . Newbu r·y 1968, Michel 1971 , Ashton 1978, and Osterkamp 1978). Frazil -Individual crystals of ice generally bel ieved to form whe al atmospher ic (cold a i r) and hydraulic (turbulence) con d itions are suitable to mainta in a su percooled ( 0°C) la ye r at the water surface (N ewbury 1968, Michel 1971, Benson 1973, Osterkamp 1978). For more information , see Section 4. 2 an d Photo 4 . 1 . Frazil Slush -Frazil ice crystals ha ve strong cohesive properties and tend to flocculate i nto loosel y packed clusters that resemble slush , (N ewbury 1968). The clusters may conti nue agglomerating and will eventually g ain s uffi c ient buoyancy to counteract the tur!;>Ulence and float on the water surface (P hoto 4.2). This s lus h is highly porous. Samples co llected at Gold Creek in October 1981 yielded a ratio of water volume to ice volume of 60-70 percent. 28 s6/i i2 Ice Constrictions -Slush ice drifts downstream at nearly the same velocity as the current . The velocity of the slush is slowed by friction against surface constrictions caused by border ice . These constrictions generally occur in areas of similar channel configuration where the thalweg is confined to a narrow channel along a steep bank . When entering constricted areas, the slush ice concentration increases and is therefore compressed. The slush ice continues to pass through the channel surface constriction and is extruded from the downstream end as a compacted continuous ribbon of ice (Photo 4 .3). The structural competence of the ice layer is greatly increased since the water fille :J interstices between the ice crystals have collapsed. As the layer of compressed slush accelerates away +rom the constriction , it b e g i r"l s to fragment into floes of various sizes, depending primarily on the f low distribution in the channel. The rafts break into floes ;w e raging 2-3 feet in diameter unless an extremely turbulent reach is encountere d where the floes disintegrate and emerge once again as small slus h 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 extr·uded through a channel surface constriction . Once this occurs , the continuous slush cover over t h e water surface freezes, resulting in an ice bridge. lee floes contacting the upstream (leading) edge of the ice bridge will either accumulate there (juxtaposition Photo 4 .4) o r will submerge u nder the ice cover . The stability of ice against the leading edge is critically dependent on the water depth and velocity. Sur'iace water veloc ities exceeding 3 ft/sec generally prevent ice accumulation (Newbury , 1968). Snow Slush -This is similar to frazil slush in appP.arance but the ~Jacked snow particles are more dense and have a lower porosity due to the smaller crystal size . Snow s lush is apparent during and 29 s6/ii3 following snowfa ll s contributing significantly to ice discharge during these periods . Shore or Border Ice -Initially, slush ice (formed by both frazil production and snowfall) drifts into and covers the zero-velocity flow margin against the river bank. Additional ice pans flowing down- stream sometimes contact this ice and accumulate against it i n a layer (Photo 4 . 5 ). This layer will continue to move downstream until frictional forces against the bank or shore ice overcome the water velocity and movement stops. The slush layers then freeze together. Shore ice w i ll continue adding layers by this process until the ice e x tends f ar out in to the river channel where flow velocities are in equilibrium with the shea r 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 ice must be extruded through under pressure. Black lea -Black ice is new i ce of continuous uniform growth. It appears dark because of its transpa r ency . It will form on the water surface in lakes and zero-velocity areas in r i vers , or underneath an existing ice cover (Michel, 1971). This type of ice normally grows in a layer under the Susitna hummocked ice cover, and can atta i n a thickness of several feet. Due to its crystalline arrangement, black ice is extremely strong (shear resistant), even in relatively thin layers , especially compared to drained slush ice . Slush ice w i ll produce floes which are i nherently weak, due to the large , well- rounded ice crystals. Hummocked Ice -This is the most common form of ice cover on the Susitna River. It is a continuous a Gcumulation of slush , ice floes, and snow that progresses upstream during freeze-up (Photo 4. 6). This process will be described in Section 4 .3 . 30 s6/ii4 4 . 2 Frazil Ice Generation Frazil ic e (Ashton, cry stals are 1978, Michel , formed when water 1971 ; Newbu ry , 1968; becomes supercooled Oster kam p , 1978). Supercoolin g is a phenomena by wh ich water remains in a liquid state at temperatures below 0°C . Foreig n particles are assoc iated with the nucleation of ice cr·ystals (Osterkamp , 1978). The Susitna River discharges treme.-.dous volumes of s ilt and clay size particles prio r to freeze-up. There is an apparent correlation between the first occur- rence of fraz il ice and a suddel) reduction of turbidity in the river water, indicating that the fine suspended sediments may initiate the nucleation of ice (R&M , 1983). Once the river is at the freezing point, snowfall also contri butes to the total s l ush ice discharge . With sustained a i r temperatures below 0°C, a thin layer of water will be cooled to the freezing point and ice crystals w ill form. Under quiescent conditions, the ice crystals will for m on the water surfa ce , eventually bonding together into a sheet of black ice , and continuing to grow vertically along the the r mal gradient. However , laboratory experiments have determined that flow velocities of only about 1 ft ./sec. are necessary tu mix the surface layer sufficiently to pr.)duce frazil (Osterk. 'tmp, 1978). These velocit1es are exceeded on the Susitna mainstem through most reach~s so that the water body is continually being mixed . Under these conditions , the water can be supe:-cooled to several hundredths of a degree below 0°C throughout the water column , and crys tals of frazil ice form in suspension be- neath the water's surface. Once the fraz i l ice forms , it has a ten- dency to rise to the surface. However , during the initial ice f orma- tion, frazil particles are so small that they remain entrained in the river due to turbulence . Channel morphology can play an important role in concentrating fraz i l ice, as indicated by ice plumes . These plumes are an ea ·ly indicator of frazil ice and have been observed at sev~ral locations between 31 s6/i i5 Talkeetna and Vee Canyon when otherwise no ice was seen . Most sites occur at sharp river bends caused by outcrops protruding into the channel. The rock outcrops often create a slight backwater effect on the upstream side . Suspended frazi1 floes are swept in to these areas and swirl about , increasing in density and ice concentra- tion until sufficient buoyancy is obtained so that the ice rises to the surface as slush . The slush floats past the outcrop in a long narrow stream wh ich is rapidly dissipated by the river (Photo 4 . 7). Any subsequent turbulence can re -entrain the slush , once again making it difficult to observe. In September these ice plumes are often o b- served near Gold Creek and Sherman . The flow patterns are such that these sites conc entrate ice throughout freeze -up . After November, the majority of frazil ice i s generated in the rapids of Devil Canyon, Watana Canyon and Vee Canyon . However, duri ng the initial freeze-up period in October 1982, the difference in the number of freezing degree days between Denali (370) and Talkeetna (170) suggests that the majority of the slush accumulating against the leading edge dow n stream of Talkeetna originates either as sn()wfall or as frazil in the upper river from Vee Canyon on upstream . This appeared to be veri f ied during a flig ht on October 21 , 1982. Esti- mates at various locati ons from Talkeetna to Watana Creek showed a consistent ice discharge in this reach, indicating that no frazil ice was being generated at the rapids at Devil Canyon and Watana on this date . Frazil ice crystals have a propensity for adhering to any object in contact with the river flow. When frazil adheres to rocks on the channel bottom it is commonly refer r ed to as anchor ice . Anchor ice has been observe::! to develop i nto ice dams on the reach between Indian River and Portage Creek (Photo 4 .8). Although these ice dams do not attain sufficient thicknesses to create extens iv e back- water areas, they increase the water velocity by restricting the cross sectional area , creating turbulence which could inc rease frazil 32 s6/ii6 generation. Slight backwater areas ma y be induced by general ra is- i ng of the effective channel bottom due to anchor ice , affecting the flow distribution between channels . On days w ith intense sola r rad iation or warm air temperatures, anchor ice has been observed t o release from the channel bottom and float to the water surface, often carrying w ith it an accumulation of sediment (Photo 4. 9). 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 advancin g ice cover . 4 . 3 Ice Cover Development This section discusses ice cover formation on the Susitna River from the mouth at Cook I nlet to the pro posed damsite at Watana . For the purposes of this d iscussion , the r iver has been separated i nto 4 reaches : Cook Inlet to Talkeetna, Talkeetna to Gold Creek, Gold Creek to Devil Canyon , and Devil C anyon to Watana. An additional section describing the unique freeze-up process in Devil Canyon is includ ed . 4 .3 ., Cook Inlet to Chulitna Confl uence Temperatures are usually not cold enough to cause significant shore ice development in this reach prior to the relatively rapid advance of the ice cov er . The i nitiat io n of ice cover formation in this reach usually occurs when tremer.dous volumes o \ slush ice fail to pass through a channel con - striction near the river mouth at Cook Inlet . Between Octo- ber 22 and October 26, 1982 , slush ice jammed a t RM 10 (Photo 4 . 10) and accumulated upstream for 57 miles to Sheep Creek. Daily ice discharge estimates from Talkeetna showed a sudden increase in ice concentrations during this period 33 s 6/ii7 (Ta ble 4 . 2). Th e ice discharge o n October 21 was estimated at 1 .3 x 10 5 c u ft/hr and rose steadily to 5.8 x 105 c u ft/hr on October 26 following several snow storms. Assuming that the ice cover began progressing upstream on October 22 , then the progression rate was 11.5 miles per day. As the ice cover moved upstrea m in 1982 , i ncreases i n water level did n ot appear to exceed 2 feet between RM 10 and RM 25 . The flow discharge at Sunshine , based o n provisional USGS estimates, ranged from 16 ,000 cfs on Octobu 21 to 14 ,000 cfs o n October 26. Large open water areas appeared frequently in the ice cover . On October 26, the ice cover was no longer continuous up- stream from RM 25. There wa ·, no ice cover or evidence of ice pr.,gression on the Sus1t11 a near the confluence of the Yentna River . The Yentna was also completely free of drifting ice and shore ice . A t RM 32 , a loosely pac ked ice cover resumed and continued upstream to RM 67. Increases in water le v el did not appear to exceed 2 feet, and large open water areas appeared frequently in the ice pack. Surprising- ly little conso lidation of the ice pack had taken place by October 26, 1982 . This could be due to the shallow gradient of the channel thro ugh this reach . In low velocity areas , the ice front continued to advance by ju xtaposition (accumulation of ice floes at the surface) at a rate proportional to the ice discharge and channel configuration . Slush ice observed at the lead ing edge was ;1ot :;ubme rgi ng under the existing ice cover . From RM 67 to RM 97 near Tal keetna, the river remained free of shore ice even though a large volume of sl ush ice was continually drifting downstream . All of the major tributaries to the Susitna b e low Talkeetna were still 34 s 6/ii8 flowing and remained ice-free. The discharge from these tributaries kept large areas at their co nflue nces free of ice. On October 28 , 183 mm of snow hll at Talkeetna. Observa - tions 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 ce pack remained confined to the thalweg channel with the e )(ception of some side chan- nel confluences where staging had created local backwater pools into which slush ice had dri =ted. The leading edge of the ice pack on October 29 was near RM 87 , 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 cove,. beginning to de- velop . At RM 76 , the cover appeared extremely loosely packed with individual slush rafts di scernible within the cover . No ice movement was detected, and the unconsolidated arrangement may have been stable . Fro m RM 7 6 upstream to RM 87 the ice c o ver was thin and discontinuous , with long open water leads adjacent to Rabideux Slough and in a side channel that extended from 1 mile below the confluence of Rab ideux Creek downstream for about 1 mile. The ice pack was diverting water into this side channel, wh ich had begun to develop an ice cov,~r by slush ice accumu 'ation. The confluence with Montana Creek was flooded by an approximate 4-foot stage increase on the main- stem (Photo 4 .11). Rabideux Slough was breached through two entranc:e channels. This was indicated by flooded s now only , and no slush ice was flowing into the slough . The margi n of flooded sno w was particularly evident near the 35 s6/i i9 Parks Highway Bridge, where it extended all the way to the northwest abutment . The leading edge had advanced to RM 95 by November 2 at a rate of 2 .1 miles per day during the previous 4 d<?.vs (Photo 4. 12). The stage had increased substantially i n th«! 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 channel is split by a forested island . The channel along the west bank remained dry and snow covered . By November 4 , river ice observers reported stage increases as the leading edge approached Talkeetna (Table 4. 2). An ice bridge that formed at the Susitna and Chulitna confluence on November 2 had greatly reduced the volume of slush ice flowing past Talkeetna, slowing the rate of ice cover advance substantially. Stage increases were over 4 feet near Talkeetna. On Novem- ber 2 a staff gage at Ta I keetna had been dry , with the nearest open water more than 1 foot below the gage . At this time the two channels of the Susitna along the eastern bank had essentially dewatered , so that the area at Talkeetna was affected by Talkeetna River flow only. The staff gage was not again accessible until after consolidation and freezing of the ice pack on November 17 , at which time the ice surround- ing the gage corresponded to a reading of 3. 6 feet (Photos 4. 13, 4 .14). This represents a stage increase of over 4 feet at Talkeetna due to the ice cover advance . 36 s6/ii10 After the initial ice cover formation, the remainder of the freeze-u p 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 haJ dropped to less than 4,000 cfs at Sunshine (USGS), most open water had disappeared. The continuous gradual reduc - tion of flow also caused the ice cover to settle . Where the sagging ice became stranded , it conformed to the configura- tion 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 from groundwater upwelling which would have b . :n sufficient to keep these chao1nels 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 su mmarizes the highli;hts and general freeze-up characteristics of the lower river f;·om Cook Inlet to Talkeetna during 1982-1983. 1 . Ice bridge occurs at a channel constriction near the mouth of the Susitna during a h!gh slush ice discharge. 2. Rapid upstream advance of an ice cover by slush accu- mulation . 3. Thin, unconsolidated initial ice cover . 37 s6/ii11 4 . Minimal staging, 2 -4 feet up to Sunshine , then over 4 feet near Talkeetna. 5. No telescoping or spr(:a ding out of the ice cover due to consolidation . Ice cover generally is confi ned to the thalweg channel. 6 . Tributaries continued flowing through December. 7. The following sloughs were breached with only minimal f low an d little ice: a. Ale x ander Slough, upper end only, no through flow. b. Goose Creek Sloug h , 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 initia l dis...,harges of 16,000 cfs at Sunshine and low final discharges of 5 ,000 cfs based on USGS daily computed values. 10. Gravel islands are seldom overtopped. 11 . Some surface flow diverted into connecting side chan - nels . 38 s6/ii12 4 .3.2 12 . Ice c o ver sagging due to decreases i n discharge. 13 . Persistence of o pen leads in s ide channels and h ig h velocity zones through March . 14 . Surface area decrease of open water by steady ice accumulations and decline of water surface . 15 . Clear ice buildup under slush ice cover. 16. Minimal shore ice development due to lack of sufficiently c o ld air temperatures before ice cover advan c es . Chulitna Confluence to Gold Creek Slush ice was first observed in the Susitna River at Talkeetna on October 12 , mar k ing the beg i nning of freeze-up . Ice studies during p revious years have observed slush ice as early as September . In 1982 , however, no field crews re- p o rted ice unti l after the snow storm on October 12 . Ice continued flowing, i n varying con c entrations , through the reach between Gold Creek and Talkeetna until November 2 , 1982 when an ice bridge formed at the Susitna-Chulitna confluence . This bridge was the starting point for the ice cover that developed over this reach. Events during the 22 days prior to the ice bridgi ng at the confluence are of significance and will be described first. This reach of river was subjected to colder air temperatures and more flowing slush ice than the river below Tal k eetna. Sho re ice had more time to develop ,. and at several locations extended far out into the channel , effectively constricting the 39 s6/ii13 slush ice flow. The higher velociti es kept the slush ice moving throug h the constrictions , and no ic e bridges formed. The Susitna Ri ver cont r ibutes approximately 80 percent of the ice at Ta l keetna, while the Chulitna and Talkeetna Rivers combined produce the rema ining 20 percent. The high (4-5 ftlsec) velocities of the Susitna kept the rive r cha nnel open , pushing the s lush ice downs t rea m . After entering the conflu- ence area, the mass es of slush ice and slowed dow n and began to pile up at the south bend of the Susitna adjacent to the east channel of the C h ulitna. On Octobe r 18 , 1982 , the slush was still moving easily through this area, but was coverin g all o f the open water f or about 600 feet with a tra n slucent sheet o f compressed s l ush ice (Photo 4 . 15). This ice accumulation was monitored frequently during October. On October 29, the ice was being compressed and bare ly kept moving by the mass of the upstream ice and by the water velocity underneath the cover (Photo 4. 16). The ice through this area was now white indica ting that the s lu sh had consol- idated and increased in thickness sufficiently to rise higher out o f the water and partially drain. The ice constrict ions being monito red on this reach were located near Curry (RM 120 .6), S lough 9 (RM 128.5) and Gold Creek (RM 135 .9). Slush ice was passing easily through these narrows on October 26 , but was being comp res sed into long narrow rafts which u sua lly broke up within several hundred feet downstrea m. Unlike the confluence area, these constrictions were formed by successive layers of frozen slush ice along the shore. A snow storm im mediately preceded the formation o f the ice bridge at the Sus itna -Chulitna confluence. This storm may ha ve caused a substantial local increase in ice discharge 40 sG /ii 14 which could not pa ss thro'-lgh t he channel at o ne time. The result was a sudden con solidation of the ice cover that com - pacted the slush and a t some point became shore-fast . The cover remained stable long enough t o free ze and increase in th ickness. The majority of the inco mi ng slush ice floes accumulated against th e leading edge and the cover b eg an advan ci ng upstream. App r oxi matel y 10-20 p er·cent o f the s lu sh ice submerged on con tact with the upstream edge and either adhered to the underside o f the cover o r conti nued downstream . Ice disc harge e stimates were substantially lowe r at Ta lkeetna after Novembe r 2 (F igure 4.1). The mo st dra- matic effect o f the ice co nsolid a tion at the confluence was flooding . The flow capacity of t he ice cho ked mai n cha nnel was greatly r educed . Water s pilled from underneath the cover, flowing late ra lly acro ss the ri v er channel towards the opposite (north) bank (Ph oto 4. 17). Wa ter was a ls o dive r t ed from upstream of the ic e jam , fl o wing i nto the new channel. These diverted flows c o mbined and entered the C hulitna ea st channel approximately 1 , 5 00 feet upstream of the origi nal confluence . The total esti mated discharge of the diverted fl o w was 700-1000 cfs , about 15-20 percent of t he total fl o w . Substantial chan nel erosion was ca used by these diverted fl ows, as subsequent depth meas uremen t t hrough the ic e located a iso lated channel abo u t 700 feet fro m the left bank . After the jam stabilized, the ice pack advanced slowly due to the increased gradient . The slush ic e could no lo nger acc u- m u late by simple juxtaposition , as the high flow v elo cities submerged the slush ice on co ntact with the leading edge. The ice cove r mo v ed u p st r eam by the staging pr·oces s , in whic h the ice cov er thickens and restr icts fl o w , causing i n c reased stages upstream of the ice fron t , T his lowe rs the upstream ve locity so that incoming ice ma y acc umulate agai nst t he leadi ng edge instead of being swept under th e ice cove r . 4 1 s6/ii15 On November 9 , 1982 the leading edge was beyond RM 106 (Photo 4 .1 8) and the ice advance appeared to have stalled. The upstream edge was located ad jacent to the head o f a flooded side channel. The ice cover was staging in order to overcome high velocities at the leading edge. However , with every ice pack consolidation and subsequent increase in stage , more water poured i nto the side c hannel , effectiv ely preventing a ny extensive backwater development upstream of the ice cover . The side channel had 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 o f slush 1ce to water volume, since o nly the surface layer of the mainstem flow was affected . Therefore , the c hanne; qu ic kly became ice-fill ed . The rate of ice advance a ve raged 1 .6 miles pe r day for thirteen days after passing Whiskers Creek. On Nov embe r 22 the leading edge was situated adjacent to Slo ugh 8A. The total estimated discharge at Gold Creek was 3,300 cfs , a decrease of 900 cfs s ince Nov ember 9. The ice cover had staged app roximate ly 4 feet and was overtopping the berm at the head of Slough SA. The estimated discharge throu gh Slough 8A was 138 cfs. Much slush ice was carried into the slough. Withi n 5 days this slough had developed an ice cover of consolidated slush from the mouth to the head near RM 126.5, w it h slush ice thicknesses of up to 5-6 feet (Photo 4. 19 ) and ice extending ove r the bank o f the island . Groundwater seeps a nd the dropping water level caused collapse of the ice cover and development of a long narrow lead . The ice cover was very slow in advancing through the shallo w section of river between Sloug hs 8A and 9. On December 2, a sudden rise in the water table at Slough 9 , recorded 42 s6/ii16 electronically in a ground water well , i ndicated the proximity of the lead ing edge (Fig ure 4.4). T he well was located adjacent to RM 129.5. The ice cover advanced a t a rate o f on ly 0.3 mile s per da y for t he previous 10 days, e v en thoug h high fraz i l s lush dis ch arges were o bserv ed at Gold C reek (Fi - gure 4 . 2). T his may reflect the consequence s of the stagi ng in t o Slough 8A . On December 9 the leading edge had reached RM 136, just downstrea m of the Go ld Creek 8 :-idge. The ice cove r advance s talled here for over 30 day s , as the ice needed to accumulate i n thickness b efore it co uld stage past this high -veloci ty chan n el const ri ction. Ic e d ischa rges estimated at Gold C reek steadi ly d ecreased throug h December, primarily because the upper river was freezing over , elimina t i n g the air/water interface need ed fo r frazil productio n. On January 14 , 1983, th e leading edge f ina lly crept past the Gold Creek Bridge (Photo 4.20) at a rate o f 0.05 miles per day. The es timate d disch arge o n January 14 at Gold Creek was 2 ,200 cfs , based on provisional USGS estima tes . Ice discharge o bservatio n s at Gold Creek for October 1982 throug h January 1983 are sum- marized i n Tables 4 .3 throug h 4 .6. The processes of ice cove r telescoping, sagging, o pen lead development and secondary ice cover progr·ession a re impor- tant characteristics through this reach. Telescoping occurs durin g co nsol idatio n o f the ice cove r . When the v eloc ity at fl oes drifting downstr ea m wi ll the surface, and accumulate a rate proportional t o the co n - the cha nnel width . Th is accu- mu latio n z o ne can be extremely long , general l y being gov - the lead i ng edge is lo w , ice c o ntact the edge , rem a in o n u pstream by juxta position at cen tration o f slush ice and to erned by the local channel g radient , amount of staging and e x tent o f the resulting backwater (F ig ure 4.3 and Tab le 4 .8 ). 43 s6/ii 17 This bui ldup will continue until a c ritical velocity is en co un- tered , causing the leading edge to become unstable w i th ice floes submerging under the ice cover. The pressure on a thin ice cover increa ses as ice mass builds up and high er veloci ties are reached in conjunction with upstream advance. At an undetermined c ritical press u re , the ice cover becomes unstable and fails . This sets o ff a chain reaction, and withi n seconds the entire ice s heet is moving downst r ea m . Several miles of ice cover below the leading edge can be affected by this consolidation. This process results in ice cove r stabi- lization due to a shortening of the ice cover , substantial thickening as the ice is com pressed , a sta ge increase , and t elescoping. The telescoping occu rs o nl y during each con- solidation . As the ice compresses downstream, tremendo us pressures are exerted on the ice cover below the acc umu la t ion zone. Here the ice mass will shift to re l ieve t he stresses exerted o n it by the upstream cove r , often becoming thicke r in the proces s . This will tend to further const r ict the flow, re s ul ting in an increase in stage. As the stage increases, the entire ice cover lifts . Any additional pressures within the ice cover ca n then be relieved by lateral expansion of the ice acro ss t he river channel (Photo 4.21). This p rocess of latera l telescoping ca n cont inue unti l the ice cover has e ither expanded bank to bank or else has encountered some o ther obstruction (such as gravel islands) on wh ic h the ic e becomes stranded. The ice cover over wate r -filled chan n els continues to floa t during ice cover progression . However, because of constan t contact with high-flowing wate r , the ice cover erodes rapidly in areas , sagging and eventually collapsi n g. In s o me reaches these ope n leads c an extend for severa l hundr·ed yards . 44 s6/; i 18 Table 4 .9 summarizes data on ope n leads photographed be - tween RM 85 and RM 151 o n March 2 , 1983. A s'!condary ice cover generally accu mulates in the open leads , often com- pletely closing the o p e n water by the end o f March. The process is similar to the in itia l progression except o n a small- er scale. Slush ice begins accumulatin g against the down- stream end of the leads and progresses upstream (Photo 4. 22). Generally it takes sever al weeks to effect a complete closure. Ice cover sagging, collapse, and open lead development (Photo 4 .21) usually occur w1thin days after a slush 1ce co ver stabilizes. A s teady decrease in flow discharge gradual ly lowers the water surface elevation along the enti re river . Also , the staging p r·ocess which had rai sed the water surface within the thalweg c hannel tends to seek an equi l ibrium level with the lower water table by percolating through the gravels of the surrounding terraces . Percolation o f river water o ut of the thalweg channel and the subsequent charg ing of the surrounding water table 1s currently under study. This process is being documented by recording the relationship between mainstem fluctuations in (Figure 4.4). water su dace elevations and relative stage groundwater wells located near Slough 9 Examination of aerial p h otog r·ap hs of the sloughs taken during the ice cove r ad vance up the ma instem revealed an increase in the wetted surface area in sloug hs wh1ch were not overtopped by staging at the upper end . This increase is attribu ted to a rise in the water table. Many of the 5 loug hs have groundwate r seeps whic h persis t thr·ough the winter . This gro un dwater is r·elatively warm , with winter t emperatures of 1°-3°C(R&M, 1982). This is sufficiently warm to prevent a stable ice c ove r from for·ming i n thes e areas not filled wit h slush ice. This relatively warm 45 s6/i i19 flow will develop ice along the margins , constricting the surface area to a nar row lead . The leads rarely freeze ove r , o ften extending for thousands of feet downstream (Table 4 . 9). Open water was obse r ved all winter in the following sloughs in this reach : Slough 7 Slough 8A Slough 9 Slough 10 Slough 11 Slough 8A was the o n ly slough breached by slush in this rea ch and co nsequently was the only one to develop a contin- uous ice cover . However, the thermal influe nce of gro und- water quickly eroded throu gh the frozen slush ice cover , and an open lead remained for the duratio n o f winter . The 1982 -1983 freeze -up c haracteristics on the Sus itna Ri v er between Talkeetna and Gold Creek a re summarized as follows: 1 . Frazil ice plumes appearing as early as September , but more commonly in early October . 2 . V elocities between 3-5 ft/sec. 3. Oischa rges at Go ld Creek ran ging from 4 , 900 cfs o n November 1 to 1 ,500 cfs by the e nd of March. (USG S esti mates ) . 4 . Ice o rid ge initiating the ice cover progression from the Susitna/Chulitna confluence. 46 s6/ii20 4 .3 .3 5 . Gradually decreasing rate of ice advance from 3 .5 mi les per day near the confluence to 0.05 m ile s per day at Gold Creek. 6 . Flow diversions into side channels and Slough 8 A . 7. Surface ice constrictions by border ice growth . 8 . Staging , commonly from 4 -6 feet . 9 . Ice pack cons0 lidation through telescoping o f 1ce cove r laterally acros s c hannel. 10. Sagging ice cover . 11 . Open leads and secondary ice c ove rs. 12 . Berm breached at Slough 8A. 13. Staging effects on the local water table. 14. Thermal i nfl ux by groundwater seepage prevents ice cover formation in sloughs that are not breached and inundated with slush. Go ld Creek to Devi l Canyon The reach from Go ld Creek to Dev il Canyon freezes ove r gradually, with comp lete ice cover occur r i ng much later than on the ri ve r below it . The delay can be expla ined by the relatively high ve locities e ncountered due t o the s teep grad i - ent an d si ng le channel , and to the absence o f a continuous 47 s6/ii21 ice pack progression past Gold Creek , due to the upper rive r having already frozen ove r . The most sig n ificant features of freeze-up between Gold Creek and Devi l Canyon are wide border ice layers, ice build-up on rocks and formation of ice covers ove r eddies. Ice dams have been ide ntified at several locations below Portage Creek (Photo 4. 23). Generally, these dam s f o rm whe n the rocks to which the frazi l ice adheres are located near the water su r- face. Whe n air temperatures are cold (less than -10°C), the ice-covered rocks will continue accumulati ng add itional la yers of anchor ice until they break the water surfac e. The ice-covered rocks effectively increase the water turbulence , stimu lat i ng frazil production a nd accelerati ng ice formation. The ice dams are often at sites constricted by border ice. This creates a backwater area b y restricting the streamfl o w, subsequently c a using extensive overflow onto the border ice (Photo 4 .24). The overflow bypasses the ice sills and re- enters the channel at a point further downstream. Within the backwater area , slush ice accumulates in a thin laye r from bank to bank and eventually free zes . Since the ice formation process in th is reach is primarily due to border ice growth , the processes described for the Talkeetna to Gold Creek reach do not occu r . There is only minimal staging. Sloughs and side-channels are not breached at the upper end , and remain o pen all winter due to ground- water inflow, although ice ca used by overflow 1s evi de nt. Open leads exist in the main channel , bu t are primarily in hig h-veloci ty areas between ice bridges. 48 s 6 /i i22 To summarize , the following are the signific ant freez e-up characteristics of the river reach between Go ld Cre ek and Devil Canyon . 1 . Steeper gradient , high velocities , single channel . 2 . Minimal conti nuous ice cover pro gression, usually onl y f o rmation o f local ice covers separated by o pen leads . Results in late freeze-over , generally i n March . 3. Extenr.ive b o rder ice growth , with very w ide la yers o f shore-fast i ce c onstricti ng the channel . 4 . Anchor ice dams c rea t ing local backwater areas which f o rm ice cov ers and ca use ove rflow . 5 . Ice cov ers ov er eddies which f o rm behind large boulders i n streamflo w . 6 . S o me teles coping , a lthough u sual ly not w idespread . 7 . Minimal staging . No sloughs breached , no diverted flow into s ide channels. 8. Few leads o pen i ng a f ter initia l 1ce c o ver . s agg i ng . Minimal ice 9 . Thermal in flu x by groundwater seeps k eeps sl o u g hs open all winter . 49 s6/ii23 4 .3 .4 Dev il Can yon (to Dev il Creek) Ice processes in Devil Canyon ( RM 150 to RM 151 . 5) create the thickest ice along the Susitna River , with measured thicknesses of up to 23 feet (R&M , 1981c ). The canyon has a narrow , confined chann~l with h igh flow v eloc ities and ex- treme turbulence , making d i rect observatio ns diff ic u lt . Consequently , in 1982 a time-lapse camera , on loan from the Geophys ical Institute, University of Alas k a , was mo unted on the s o uth rim of the canyon (Photo 4. 25) to d o cument the processes causing these great ice thicknesses . The t ime -lapse camera ;:>rovided d ocumentation that the ice form a tion through Devil Can yo n is primarily a staging pro- c ess . La rge v o lumes of slu s h ice enter the can y on , and additional frazil ice is g enerate d i n the c an y on . The slush ice jams up in th e lowe r c an yon (P hoto 4 . 26), and the ice cover pro gresses up the can yon thro ugh large staging pro- cesses . Howe v er , the slush ice has little strength , and the center o f the ice c over rapidly c o ll a pses after the downstream jam disappears and the water drains from beneath the ice. The slush ice bonds to the canyon walls , increasing in thick- ness eac h t ime the staging pro cess occurs . The ice c o ver f o rms and erodes sev eral t imes during the winter . The following chronolo gical sequence of events was com pi led fro m examination o f the film . The descript ions will b e g in o n then taper to week l y and monthly descriptions as fewer changes were observed . Air temperatures (mean da ily °C ) were obtained from the meteorological record of the Devil C a n yo n w eather .. ~"'t io n . Streamflows are provisio nal estimates fro m the Go ld Creek Station and are subject to re vision b y the U .S. Geologic al Survey. Ice thicknesses are estimates f rom the f ilm reco rd . 50 s6/ii2 4 October 18 , 1982 Air temperature -5.0°C , discharge 6, 720 cfs . The c hannel appeared open with n o ice bridges and n o constrictio ns . 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 c hannel was partially o bscured. It appeared to be comp letely filled with slush ice with no o pen wabr visible. Staging of at least 3 -4 feet was ev;:lent. The channel r emai n ed ic .. ' covered throughout the day and the snow ended about 2 p .m . October 21 -Ai r temperature -9 .5°C, d ischarge 6 ,500 cfs . No s ignificant cha nges as the c hannel remained ic e covered all day w ith no open leads appearing. The weather was clear and sunny with swaying trees ind icating high winds. October 22 Air temperature -9 .6 °C, disc har·ge 6,200 cfs. The ice cover began to sag in the center o f the channel and submerged . The flooding ice cover r c>;:>ld ly eroded away . Ice along the s ides of the now ope n lead co ntinued to c alve off in t o the open water a n d mel t. October 23 -Air temperature -9.8°C , disch arge 6,000 cfs . It snowed heavily early i n the morn i ng , tapering off <1round 10 a.m. Open le ads were clearly visible i n the hi gh-velocity reac hes . Water sa tura ted ice remained i n some a rea s o f lowe r velocity where erosional forces were not as severe . Little c hange was notice d during th e day. October 24 -Air temperature -10.S°C , discharge 5 ,900 cfs. Large volumes o f frazil were fl owing 1n the open cha nnel . An ice cover had aga in formed over the downstream portion of the ope n water lead . T h e upper portion remained ope n where 5 1 s6/ii25 apparently the water velocities were sufficiently high to prev ent further ice cover progress io n at the prev ailin g ice discharge. During the day , the ice cover over the lower rea ch rapidly deter iorated by sag gi ng and eros io n . The floating ice cover was !"low sagg in g so far down tnat it sheared ve rti cally from the shore -fast ice and floated within the open lead (Photo 27). This subjected the fragmented ic e cover to the full v eloc ity of the water, quickly erod ing the ice away. The fl o ating ice seemed to ride ve ry lo w i n the water , at times submerg i ng comp letely . T h is is probably due to the high p o rosi ty ot the s lush ic e wh ich i nitiall y formed the cover. October 25 -Air temperature -12.8°C, discharge 5, 700 cfs. There were no apparent c han ges, as part of the channel was still partially covered , with the remainder being choked with fl oa t i ng water -saturated ice. Ice shelves o n the banks were approx imately 3 -4 feet thick. October 26 -Air temperature -15.4 °C, discha r ge 5,600 cfs. The images of the canyon were obscured by hea vy fog , but the channel seemed t o be ice covered with no open leads d isce rnible. October 27 -Air temperature -19.1°C, discharge 5,400 cfs . There were no apparent changes. The ice cover ramained intact and no water was visible. October 28 -Air temperature -13.2°C , d i scharge 5 ,300 cfs . Overnight , an op en lead developed in the upstream rapids sed ion. No f urther· chan ges were noted on this day . October 29 -Air tempe r ature -13 .3°C , discharge 5 ,200 cfs . Fog again partia l ly o bscu red the images . The open lead at 52 s6/i i26 the upstream end of the reach expanded in width and length. It appeared to be open for its entire wetted width and no overhanging ic e shelves remained. This open water r·each extended upstream ou t 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 o ther . October 30 -Air temperature -1 9 .1°C , discharge 5,100 cfs. The first hour of da yligh t 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 collap sed and formed a narrow channel. The channel then widen ed considerably , with the downstream end located j ust above the south river bend. The upstream end was not visible. However , the upstream reach through the canyon is generally open because of ext reme turbulence and high v ::- locities. Octobe r 31 -Air tem;:>e rat ure -1 5.9°C, discharge 4 ,900 cfs. The channel constriction of October 31 closed again, separat- ing 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 ba nk . November 1 -Ai r temperature -4.5°C, discharge 4,800 cfs. The first exposure of the day revealed o ne long ope n lead running almost the entire length of the visible ca n yon. The border ice shelves were the only ice remarn ing within this reach of the canyon . These appeared to have thicknesses exceeding 10 feet in some places , parti cula rly at the upstream 53 s6/ii27 channel constriction. This is also usually the first ar·ea to bridge ove r . November 2 -Air temperature -5 .1°C , discharge 4 , 700 cfs. 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. Severa l advances of 20-30 feet were visi ble 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 adva nced about 100 feet overnight. The cover appeared to be thin , and did not come c lose to the top ele- vation of the shore ice. A lthough much ice was evidently flowing, it all seemed to be submerging underneath the exist- ing cover and not accumulating against the leading edge. Thi s indicates that the ice cove r was thickening at some point downstream. No appreciable upstream advance occurred on this day . November 4 -Air temperature -2.9°C, discha rge 4,500 cfs. The ice cover had not advanced since the previous day, but has instead t hic ken ed and staged substa ntiall y. In the lo wer reach, the diffe rence in elevation between the top o f the shore ice and the ice cover in the c h anne l was no less than 2 feet. November 9 -Ai r temperature -7.1°C , discharge 4 ,100 cfs . Little change was apparent in the ice regi me despite a high vo lume of flowing ice. November 14 -A i r temperature -6.2°C , discharge 3 ,800 cfs . The p ast 5 days showed littl e cha n ge in the shape or size o f 54 s6/ii28 the open lead except for minor advances of 10-20 feet at the lead i ng edge. These subsequently consolidated , relocati ng the ice fro nt to its origina l position. On this day the ice cover finally closed the lower canyon reach . The upper lead remained open , but a ve ry high volume of slush ice co uld be seen flow i ng within the lead. This sudden increase i n s lush ice concentration was probably related to the rapid ice cover formation in the lower canyon. A correlation between snowfal l on November 14 and ice discharge can be seen, and is illus - trated in Figure 4.2. November 15-21 -Discharges dropped from 3, 700 cfs down to 3,400 cfs. Ice covers formed re peatedly over the lowe r canyon reach but seemed to be extremely unstable. The covers typically lasted only a few days, with destruction genera lly o :curring c o in c idently with a decrease in ice dis- charge. The durati o n o f ice cover deterioration was variable and probably depended on ve loc ity as well as climatic con- ditions . December -January -Discharges fell from 3,0 00 cfs down to 2,000 cfs . No new processes were observed during th is 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 b o rder ice const riction and ex- tended beyond the south river bend. This cover did , howev- er, eventually develop cracks . A sag appeared, the ice finally collapsed, and open water showed through . The final exposu res , in F ebruary, clearly showed the ice co v er begin - ning to fai l along its entire length. This seems to indicate tha t the ice covers within this narrow and turbulent river reach are i nh erently unstable. 55 s6/ii29 There were a total of 6 ice cove r advances on the lower reach and 3 on the upper . This difference is due primarily to a steeper gradient , higher velocities and turbulence in the upper section. Only during extreme ice discharges did the upper reach f o rm an ice cove r . The initial ice cover d e- veloped in Octobe r over both reaches , but rapidly eroded away , le aving on ly remnant shore ice. The seco nd major ice cover event occurred in December , with the final ice cover forming in January. All of the major ice advances seemed to be related to heavy snowfalls. A storm i n January left an ice cover on the lower reach which appeared t o be stable. The low discharges in January cou ld explain the longevity of this ice cover. Devil Canyon and the reach between Devil Creek (RM 161) and the Devil Canyon dam site (RM151) have the firs t areas on the Susitna to form ice bridges and develop an extensive ice cover. Ice covers of one mile 1n length were observed t" form about two miles below th e Devil Creek c o nfluence as early as October 12 , despite relatively warm air temperatures. The ice format ion process at this point is belie ved to be similar to that in Devil Canyon. To summarize the h ighlights of freeze-u p 1n Devil Can yo n : 1. Na rrow, confined channel with high flow velocities and turbulence . 2 . Earl y formation of ice bridges and loos ely packed s lush ice covers. 3. Formato v n and erosion of ice covers several times during the winter. 5 6 s6/ii30 4.3.5 4 . Inherently unstable tee covers, eventual collapse long bef ore breakup. 5. Extreme staging and ice thicknesses up to 23 ft . Devil Ca n yo n to Watana This s ection o f the river has n o t been th o r·o ughly studied . Ho wever , SO!'Jle general comments on the freeze-up processes affectin g t his reach can be made. These are based mostl y on ice format ions observed during breakup a fter the snow had melted o ff of the ice cover. An accumula ti on of border ice layers is primarily res po n si ble fo r the ice cover d •'velop ment (P h o to 4 . 27). The border ice o ften constricts the open wa te r chan nel to less than 30 feet . The slush ice then j a ms in between the s hore -fast ice and freezes , for·ming an unbroken , uniform ice cover acro ss t he r i,:er channel. However , since thi s p r ocess does not occur si mul taneously ove r the entire reach , a v ery discon tinuo us ice cove r resu lt s. Open leads gener ally abound u ntil e arly March when the comb inat ion o f snowfall and ove rfl o w c lo ses mos t of the openings. Characteristics of freeze-up between Devil Ca n yo n and Watana are summarized as follow s : 1. E xt remely wide acc umulations o f bord e r ice la ye rs , resu lting in gradual filli ng o f the narrow open channel with sl ush whic h freeze s and forms a contin u ous ice cover . 2. Extensi v e overflo w and flooded sno w . 57 s6/ii31 4.3 .6 3 . Minimal staging or telescoping. 4. L ow discharges , resulting in sha llo w water and modera te v e locities . 5. Mini mal ice sagging, few leads open ing after initial freeze-up. 6 . Extensive anchor ice with h ig h sediment concentrations . Ice Cove r at the Peak o f Development The ice cov er o n the Su s i l na Ri ve r is extremely dynamic . F rom the moment th a t the initia l cover forms , it is either thicken i n g o r erod ing . Slush ice will adhere t o th e unders ide of an ice cover in areas o f l o w ve locity , with cold tempera- t u res subsequentl y bonding this new layer to the surface i ce . Table 4. 7 l ist s Susitna i ce cove r thicknesses measured be- tween Watana and the Chulitna confluence. These mea sure- ments repres e n t the cover at ma xim um development i n 1983. If the ice cover could eve r be considered stable , i t would be at t he h e ;g ht of its maturity in March . During th i s period o f the winter , snowfalls become less frequent and very little frazil slush is ge nerated . The only air-water interfaces are at the numerous open leads whi c h pe r sis t over turbulent reaches o r groundwate r seeps . These are usually o f short length with Ins u ff icient heat exchan ge ta ki ng p lace to g e n e r- ate significant amounts o f frazil ice . Tab le 4.9 presents the lo~ations and dimensions o f most annually recurrin g leads between S u,s hine a n d Devi l Canyon . 58 s6/ii32 Discharges i n March a r e ge nera ll y at the annu al minimum, reducing the flowing water t o a shallow and narrow t ha lweg c hannel, indicated by a depression in the 1ce cover. The depressio ns f o rm shortl y after ice cover f o rmation when the compacted slush ice is fl exi ble and porou s . Wa ter leve ls decrease through March, resu lting i n the floating ice c ove r grou nd ing o n the ri ve r botto m . Wate r gradually percolates o ut o f the cover . Alte rn ating layers o f bon d ed a nd unconso l - idated ice c r ystals form within the ice pack when the receding level of saturated slush freezes at ex t reme air temperatures. The resul t is the f ormation o f rig id la yers at random lev els , w i t h th e layers represen t ing t he frequency o f critica lly co ld periods . 59 s5/ii1 TABLE 4 .1 SUSITNA RIVER SU RFACE WATER TEMPERATURE PROFILE* SEPTEMBER 1982 -O C T O BER 1982 Water T emeeratu re °C Mean Seetember 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 C amp , 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 Temeerature °C Mean October 1 -17 , 198 2 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 LR X-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). 60 s 5/cc4 Date October 1982 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Nov ember 1982 1 2 3 4 5 6 7 8 9 10 11 12 T AB LE 4.2 SU SITNA RIVER AT TALKEETNA FREE ZEU P OBSERVATIONS ON T HE MAI NST EM Staff Discharge Gauge ( 1) @ Sunshine(2 ) 0o lce(3) if.!.L (cf s ) in C hannel 1.65 20 ,000 0 1.68 20 ,000 10 1 . 55 20 ,000 0 1.42 19 ,000 30 1. 25 18 ,000 30 1 .30 17 ,000 25 1 . 24 17 ,000 25 1.23 17 ,000 25 1. 20 17 ,000 20 1. 15 16 ,000 30 0 .98 16 ,0 00 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 ,0GJ GO 1. 52 12,000 50 11 ,000 40 11,000 50 3.60 (Top of ice after freez e up) 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 Ice Th icknes s (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 .3 0 3 .30 3.30 1 . Re lative e l ~;vations based on an arbitrary datum . Gage located near chan nel adj acent to T a l keetn a. 2 . Provisional data subject to revisio n by the U.S . Geo log ica l Survey, Water Resources Division , An c h orage , Alaska . 3 . Visual estimation based on o ne daily observat io n , usually at 9 a .m . 61 0'1 N s5/d d1 TAB LE 4 .3 SUS I TNA RIVER AT COLD CREEK FREEZE-UP OBSERVATIONS ON THE MAIN STE M Octo ber 1982 Co l d Creek Mea n Air Wat er I ce in Bord er 1 ce Snow 0 i scha rge ( 1 ) Tempera ture (2 ) Tempe r ature (3) Channe l ( 4) Thickness Depth Oa te (cfs l ( OC) ( OC) (%! ( f~ l Lf..U_ Wea J.he r Oct. 19 6900 -1 0 ,, 0.65 50 s lush 0.6 s now 20 6800 -5.0 0.80 40 s l us h 0.6 C l ouuy 2 1 6500 -5.6 1.00 60 slus h 0.6 Windy/Sunny 22 6200 -4 0 '~ 0.90 60 0. 3 0.6 Wi ndy/Sunny 2 3 6000 -9.2 0 .80 65 0 .3 0.6 Windy/Sunny 2 4 5900 -7.8 1 0 00 50 0 .3 0.6 Partly C l oudy 25 5700 -1 0.0 1 0 00 60 0.3 0.6 C l oudy 2 6 5600 -14 .4 0.50 60 0.3 0.6 C l oudy 27 5 110 0 -1 3.6 0.20 65 0.4 0.6 Sunny 28 5300 -7.8 0 .00 65 0.4 1.0 s now 2 9 5200 -6.9 0.00 70 0.5 1.5 Snow 30 2 100 -18 .3 0. 10 70 0. 7 10 5 Su nny 3 1 lt900 -17.8 0.00 70 0. 7 1. 5 Sunny 1 . Provisiona l dat a s ubJ eC t to revisio n by the U.S. Geolog i ca l Survey, Wat er Resources Di vosion, An chorage , A l aska. 2 . Average va lue of the uays minimum and ma x imum t e mpe rat ure. 3. Based on one in stan t a neou s measure ment , usually taken at 9 a.m. daily. 4. Vi s u a l es t i mate based on o ne in s tantaneou s ob servation , u s ually at 9 a.m. daily. s~/dd 2 TABLE 4.4 S USITNA R I VER AT GO LD C~EE K FREEZE -UP OBSERVATIO NS ON TH l MAINSTCM November 1982 Go ld Creek Nean Air Water I ce in Border Ice Snow Discharge ( 1 ) Te mp e rature ( 2) Temperat u re ( 3) r 1a nne I ( 4) lhi ckness Depth Uate __ Ccfsl ( oc ) (°C ) _l$.L_ __LL.U __ .Lf.!J_ we a !,her No v. 1 48CIO -2.2 0.00 70 0.9 1 . 5 Wind y/Cloudy 2 11700 1 . 1 0.10 20 0.9 1 . 5 Snow 3 4600 -6.9 0 .2 0 50 0.9 1.7 C loudy 4 11 ~00 -3.3 0.30 15 0.9 1. 8 C loudy 5 1111 00 -6. 1 0. 40 10 0.9 1. 8 C lou dy 6 4300 -1 6.9 0.30 50 0.9 1. 8 Sunny 7 11 300 -17.8 0.20 55 1 . 0 1. 8 Sunny 8 4 200 -7.5 0. 15 5~ 1 . 2 1 .8 Snow 9 4100 -5 .6 0. 15 5 5 1. 2 2.6 Cloudy 10 4000 -5.0 0.30 50 1 .2 2.5 Cloudy 1 1 4000 -1. 1 0 .20 50 1. 2 2.5 Snow 12 3901) -1.9 0.20 35 1. 3 3.3 C loudy 13 3800 -3 . 1 0.20 35 1.3 3 .3 S unny 14 38011 -1.9 0.20 30 1 . 5 3.4 C loudy 1~ 3700 -1 2.2 -40 1.5 3.4 Sunny 16 3600 -1 5.8 -60 1. 6 3. l j ~·•nny (j\ 17 3600 -1 5.0 -70 1.6 3.4 Su nny w 18 3500 -22.8 0. 30 70 1.6 3.3 S11n1o y 19 3500 -25.7 0.20 75 1. 7 3 .3 S unny 20 3400 -1 0 .0 0.30 70 1 . 6 3.3 S now ?1 3400 -6.4 o. 30 60 1. 6 4 . 1 S now 22 3300 -5.0 0.40 55 1. 6 11.1 Sunny 23 33011 -4.4 0. 30 4 5 1. 3 Ll . () S unny 2 11 3 200 -3. 1 0. 30 30 1 . 3 4.0 Sunny 25 32()0 -2 .8 0.50 40 1.2 3 .9 Sunny 26 3 100 -3 . 1 0 .40 50 1 .2 3.8 Sunny 27 3 100 -8.3 0 .11 0 50 1 . 2 3.8 Sunny 2R 3 100 -1 2.8 0.50 60 1 . 3 3 .8 Sunny 2 ':1 3000 -9.7 0.30 60 1.3 3.8 Snow 30 3000 -8.9 0.20 40 1. 3 3.8 Cloudy 1 . Provi s ional data s ullJ8CL to revision by Llle U.S. Geo l ogocal S urvey, WaLer Resources Oivi s 1o n, An c h orage , A l as ka. 2 . Average value of Lhe day s minimum and ma x imum Lemperature. 3. fla !.ed on une ins t antconeot•s measuremen L, usually taken at 9 a.m. da i ly. 4 . Vi s ual es timaLe lla sed o n one insta ntan eous ollse r vatio n, u s ua ll y at 9 a.m. da• ly. SJ/tld 3 TABLE 4.5 S US ITN A RI VE R AT CO LD CREfK FREEll-UP OBSE RVAT IONS ON TH E MAIN S I EM Decemb er 1982 Gold C r ee k Mea n Air Wa t er I ce i n Bord e r I ce Sn o w D i scha rge ( 1 ) Tem pe r a ture ( 2 ) Te mpera to re ( 3 ) Ch a n ne l ( 4) Th oc kne s s De p th Dat,c -l£.[~ ( OC) (°C } ('X,} __Lf!.l__ lil.L Weather Dec. 1 3000 -7.8 0 . 10 30 1 . J 3. I~ C l o udy ? 2900 -1 6.9 0 .10 55 1.3 3 .3 C I Olt d y 3 2900 -1 6.9 0.00 70 1 . 3 3 .3 Wi ndy/Sunny IJ 2900 -1 0.0 0 . 10 75 1 . 3 3.3 C I o wl y 5 281\0 -8.3 0.20 I') 1 . 3 3.3 C l o utl y 6 2800 -1 . 7 0.20 6 5 1 . 3 3.0 Sunny I 281lll 2.5 11. 30 11 0 1.3 3 .0 Wondy/C i oudy 8 2 700 3.6 0 .20 15 1 .1 3 .8 Snow 9 2"100 -1.9 0 .20 25 1 .1 3.9 Cloudy 10 27 00 -1 6. 1 0 . 10 60 1.2 3 .9 Sun ny 1 1 2600 -6. 1 o.on 40 1.3 3.9 Su nny 12 2600 -3. 1 0.00 60 1.3 3 .8 Clo udy 1 3 2600 -1.7 0. 10 110 1 . 3 3.8 Su nny )II 2 600 -').0 0.20 25 1 .? 3.8 Sunny 1') 2600 -0.3 0 .20 10 1 . 2 3.8 Sunny 16 250U -3.3 0 . II) 10 -3.7 Sunny 17 2500 -6 .7 0.10 10 -3.7 Su nny 0"1 18 251)0 -1 0.6 0.00 50 -3 . 7 Su n ny "'" 19 2 11 00 -11 . 7 0.00 1~0 -3.7 Su nny ?n 21100 -I . 2 0.00 40 -3. 7 Su n ny 2 1 2 4 00 -2 1 . 1 0.00 50 0.5 3 . 1 Su n ny 22 2 11 00 -23. 1 0.00 50 0.5 3.7 Su nny 23 2 4 00 -1 5 .6 0 .00 30 0.5 3. 7 Sunny 2 11 2 1~0 0 -11.9 0 .00 30 0.5 3.6 S u nny 2J 2 300 -9.2 0.10 30 0.6 3.6 S unny 26 2300 -5.6 0 .1 0 30 0.6 3 .5 S unn y 2 1 2 4 00 -1.1 II . 10 35 0.6 3.5 Snow 2 8 2 1100 0 .6 ---5.0 S no w 29 2600 1 . 7 ll. 10 5 overfl ow 3. 1 Ra on JO 280(1 -0 .3 0. 10 25 overf l o w 3.2 Rain 3 1 2900 -0.10 5 1.3 3.2 Sunn y 1 . Prov i s i ona l d a t a s ubJeC t t o revis i o n b y t h e U.S . Geo l o g ica l Survey, Wa t er Resourc es Divi s oon , An c h o r age, AI aska. 2 . Avera g e va lue of the d ays mi nomum a nd ma x imum t e mpera tu r e . 3 . Based on une in s t a nt a ne ou s meas u reme nt u s uall y taken at 9 a .m . d a il y. II. Visu a l es to ma t e base d o ro o ne i ns tanta n eou s o b serva to o n, u s uall y a t 9 a.m. daol y. (j\ V' S~/lldl~ Di sc h arye ( 1) -~-e __ ( c f s l - J a n . 1 2 900 2 2 800 3 2 800 I I 2700 ~ ~~ 2100 6 2600 7 2~00 8 2500 9 2 ll 00 10 2 4 00 11 2 401) 12 23 00 13 2300 111 2200 * Go ld C r ee k Mea n Air TABLE 4.6 SUS ITNA R I VER AT GOLD CREEK FR EEZE-UP OBSERVATIONS ON Til E MAIN STEM J a nuary 1983 Wat er I ce in Temp e ratu re (2 ) Te mperature (3) Channe l ( 4) ( OC) ( °C l _il l -2.8 0.00 8 -2.8 0.00 10 -3.9 o.on 30 -5 .0 0.00 60 -1 3 .9 0 .1 0 6~ -1 9. 1 0 . 10 65 -o .ou 70 -25.3 0 .00 65 -22.2 0.00 60 -2 0.6 0.00 70 -1 6.7 0.00 85 -18 .6 0.00 90 -16.7 0.00 90 -13 . 1 0.00 100 Bord er Ice 1 hlt:kness ( ft l 1.3 1 . 3 1 . 3 1 .11 1.3 1 . 3 1 . 3 1. 3 1 .11 1 .11 1 . 4 I . 5 1.5 1 . 5 S n ow Depth Lf.1j_ 3.2 3.2 3.5 3.5 3.5 3.5 3.5 3.3 3.3 3.0 3.0 3 .0 3.0 3.0 Wea t.hcr Sunny Sunny Cloudy S unny S unny Su nny S unny S u nny S unny ll igh Wi nds Sunny Sunny Sunn y Su nny 1 . Prov i s ional data s u bJeC t t o r ev ision by t h e u.s . Geo l ogical Survey, Wate r Reso u rces D1vis1on, Anc h orage, A la ska . 2 . Average value of the days minimum and ma x 1mum te mperature . 3 . Based on one ins t ant ilneou s meas ure men t, usually t aken at 9 a.m. d a il y. 4. Vi s u a l es timate based on one i nsta ntaneous observat i on, usually at 9 a .m . d ai l y. Ch an ne l fr'o/en o ver. 0\ 0\ ::.~/ JJ 1 TABLE 4 o I 1983 SUS ITNA R I VER I CE THI CKNE SS MEAS URE MENTS Ma1n s t e m I ce Thicknesses (ft) Nurnb e r Water S urface --.!1l.!L ~ -.AY.!L of llol es [I eva t • on Lo b £lli!.£~.!L.__!2!U Wa tana 1 oll 3o6 2o 4 2 1 14 3608 Po rtage Cree k 1 0 I~ 3 oi l 2 05 5 83110 1 Go ld C r ee k 1 0 3 1o 9 1 o6 5 61\40 6 Cur r y 1o8 2 0 1 1.9 II ~2207 I ~X-3 2 o0 3 o9 2 o9 5 3 4 208 Aurt I 12 1.2..§.1 Wa tana 1 0 8 40 2 2 o8 19 14 36o 1 Pc>rt<tge Cree k 3on IL O 4 0 1 6 8 3 3o'.l Go ltl C r eek 1 0 8 2 09 2o3 6 682o9 Curry 1 0 3 3 o3 2 02 7 52 1 0 9 LHX-3 2 00 3o6 2o8 7 311 1 0 5 .. Average underice water ve l oc itY was measure d a t po1nt of mo s t flow and c onstitutes an average of the ver t1 ca 1 v ~l o c tty prof i l eo Avoraye * Under ice Water VC IO Ct t .Y 2 o6 2o ? 4 o2 (11 ...J S~/ff 1 TAI}LE 11 .8 R I VER STAGES AT FREEZEUP MEASURED FROI1 TOP OF ICE ALO NG BA NKS AT SELECTE D LOCATIO NS Open Wat.er E 1 eva L ion Ma x imum Doscharge USGS Co mp ut.e d App rox i rna te Top of Ice Corresponding Do sc hary e at R over DaL e of River Bank E l eva Lo on* LO S tage Gold C r oe k lliJJL Loca tion Freezeu o I fL l I ft l l c f s l I c f s 1118.9 f'or t.a ge Creek 12/23/82 843.0 839.5 27 .000 2 ,400 1ll l'. 3 Slough 2 1, 1-19 -158. 3 7 55.5 11 10.8 S l oug h 2 1 , LRX -511 -735.3 733.3 136 .6 Go l d Creek 1/14/83 687.0 685.3 16 ,000 2 ,2 00 135.3 s :oug h 11, Mout h 12/6/82 67 1 .5 --2,800 130.9 S l oug h 9 , Sh e om an 12/1/82 622.11 6 2 0.1 30 ,000 3,000 12 8.3 S l oug h 9 , MouLh 11 /29/82 -16.91 -3 ,000 :::7.0 S l ough 8, Head 11 /22/82 -519.3 -3,300 124.5 S l oug h 8 . LRX-2 8 11 /20/82 556.2 559.3 44,000 (aufe os ) 3,4 00 120. ( Cu rry, LRX-211 11/20/82 527 .0 52 1~. 6 28,000 3 ,400 116.7 Mc Ken z oe Cr e ek 11/18/82 -493.3 -3,500 11 3. ( La ne Creek 11/1 5/82 -I 6. 71 -3, IO U 106.2 LRX -11 11/9/82 -I 5. 3 1 -4 , 100 103.3 LR X-9 11/8/82 384. 1 383 .9 111,000 11,2 00 98.5 LR X-3 11 /5/82 346.4 345.5 -4 ,4 0() * Val ues on urac kets 1 1 rep r esent rela ti ve e l e vat i ons based on an assumed datum f rom a Lemporary benchmark all ja ..:e llt LO the so t e. S 16/ X 1 Location of Ups team End River Mi le # 85 .0 87 .1 87.6 89 .0 89 .5 91.0 ~2.3 93.7 94.0 95 .2 96 .9 97 .0 102 .0 102.9 103.5 104. 1 104.5 104.9 105 .9 106 .1 106 .4 106 .6 107.4 109.1 110 .3 110.5 110 .9 1 11.5 111 .7 111.9 112 .5 1 12 .9 113 .8 117.4 117 .9 119 .6 119.7 TABLE 4 .9 MAJOR ANNUALLY RECURRING OPEN LEADS BETWEEN S UNSHINE RM 83 AND DEVIL CANYON RM 151 LOCATION AND SPECIFICATIONS ON MARCH 2, 1983 T ype Chann el of Approx. Widest T~~e Lead ( 1) Length ( Ft) Point (Ft) Main stem Velocity 550 80 Slough Velocity 4 ,500 50 Main s tem V elocity 700 100 Main stem Velocity 1,200 100 Side Channel Vel oci ty 2 ,500 40 Main stem Velocity 1,400 60 Mainstem Velocity 1 '700 80 Main stem Veloci ty 1 ,300 110 Main stem Velocity 3 ,500 110 Main stem Thermal 3 ,500 20 Side Channel Velocity 2,400 100 Side Channel Velocity 5 ,600 150 Main stem Velocity 1 ' 100 30 Main stem V elocity 2,400 100 Mainstem Velocity 600 100 Main stem V elocity 1,850 100 Mainstem Velocity 280 70 Main stem Veloci ty 1 '700 110 Matnstem Velocity 900 150 Mainstem Veloci ty 1,050 100 Main stem Velocity 200 GO Mainstem Velocity 370 50 Mainstem Velocity 350 50 Main stem Velocity 200 50 Main stem Velocity 550 100 Mainstem Velocity 150 100 Main stem Ve locity 290 50 Main stem Velocity 450 50 Mainstem Velocity 1,600 100 Mainstem Velocity 500 90 Main stem Velocity 900 150 Main stem Ve l ocity 700 100 Main stem Ve l ocity 500 1 10 Main stem Ve l ocity 600 110 Main stem Thermal 780 60 Side Cha nn el Thermal 1 '260 120 Side Cha nnel Thermal 550 50 Mai nstem Velocity 350 50 68 Contin u ous or Discontinuous Continu ou s Discon t inuous Continuous Conti n uou s Continuou s Discontinuous Discontinuous Discontinuous Continuous Discontinuous Continuous Discon tinuous Continuou s Discontin uous Conti nuous Discontinuous Continuou s Continuou s Continuous Continuous Continuous Continuous Di scontinuous Continuous D iscontinuous Discontinuous Conti nuous D iscon tinu ou s Con tinuous Conti nuou s Continuous D 1scontinuou s C o ntinuous --on tinuous Continuous Disco ntinuous Cont i nuous Continuous s16/x2 TABLE 4 .9 (Continued) Location of Type C o ntinuous Upsteam End Channel of Approx. Widest o r River Mile # Type Lead ( 1) Length ( Ft) Poi nt ( Ft) Discontinuou s 120 .3 Mainstem Velocity 800 1UO Continuous 121 .1 Main stem Velocity 550 100 Contin uous 121 .8 Side C hannel Thermal 1 ,450 30 Disc o ntinuo ~J s 122.4 Slough (7) Thermal 1 ,850 60 Discontin u o us 122.5 Slough (7) The rm al 380 50 Continuous 122.9 Slough (7) Thermal 1 '950 80 Discon t inuou s 123. 1 Main stem Veloc ity 1 ,000 80 Continuous 123.9 Side Cha nnel Thermal 200 50 Continuo~s 124 .4 Side Channel Veloc ity 270 40 Continuous 124 .9 Main stem Thermal 600 90 Continuous 125.3 Slough (8) Thermal 3,500 50 Disco ntinuous 125.5 Main stem Veloci ty 2 ,140 100 Continuous 125.5 Slough (8) Thermal 800 500 Continuous 125.6 Mainstem Veloci t y 350 60 Continuous 125.9 Slough (8) Thermal 580 50 Continuous 126. 1 Slough (8) Thermal 500 30 Continuous 126.3 Slough (8) The rmal 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 S l ough (9) Thermal 5,060 100 Con tinuo us 128.5 Side Channel Thermal 1 '210 30 Di sconti n uou~ 128.8 Side Channel Thermal 380 20 Continuous 129.2 Slough Therm al 4 ,000 30 Discontin uous 130 .0 Main stem Velocity 600 90 Continuous 130.8 Side Channel Thermal 5 ,000 50 Dis co ntinuous 130.7 Main stem Veloci t y 150 50 Continuous 131 . 1 Main stem Velocity 490 90 Continuous 131.3 Main stem Veloc ity 800 100 Continuous 131.5 Side Chan nel Therma l 5,000 80 Discontinuous 131.3 Side Chan nel Thermal 900 90 Discontinuous 132.0 Main stem Veloci ty 150 20 Continuous 132. 1 Main stem Vel ocity 500 20 Discontinuous 132 .3 Main stem Velocity 400 80 Continuous 132.6 Main stem Velocity 1 ,350 80 Continuous 133.7 Slough Thermal 6,000 60 Continuous 133.7 Main stem Vel oc1ty 1 '11 0 100 Continuous 134 .3 Slough ( 10) Thermal 4 ,500 40 Continuous 134.0 Side Chan nel Thermal 1 ,200 50 Continuous 134.5 Side Channel Th erma l 850 100 Continuous 135.2 Mainstem Velocity 1 '580 90 Discontinuous 69 s 1 G/ x3 TABLE 4 .9 (Con t inued) Location of T ype Con t i nuous Upsteam End Channel of Approx. Widest or River Mile # T 1:e e L ea d (1) Length ( Ft) Poin t ( Ft ) D i sconti nuous 135.7 S loug h ( 11 ) Thermal 5 ,500 80 Conti nuo us 13 6.0 Mainstem Veloc i t y 230 80 Continuous 136 .3 Side Channel Th ermal 2,050 40 Conti nuous 136 .7 Main stem The rma l 1 ,620 80 Co ntinuous 137 . 1 Main stem Veloci ty 750 60 Co nti nuo us 137 .4 Side Channel Thermal 2,500 20 Disconti nuous 137 .8 S lough ( 16) Thermal 1 ,400 30 Disconti nuous 138 .2 Main stem Velocity 2 ,000 150 Conti nuo us 138.9 Main stem Thermal 2,100 150 Con tinuous 139 .0 Main ste m Veloci ty 780 20 Conti nuous 139 .1 Mai nstem Velocity 500 30 Conti n uou s 138 .4 Main stem V e locity 600 30 Continuous 140 .6 S i de C h a nnel Thermal 1 '900 100 D i scontin uou s Slough (20) Therma l 1 ' 100 20 Conti nuous 142 .0 Slcugh (21) Thermal 3 ,850 40 D iscontinuous 141.5 Mainstem V el oc i ty 850 40 Continuous 142 .0 Mainstem Veloc 1ty 950 50 Co nt i nuous 142 .6 Mainstem Velocity 1 ,600 150 Discontinuous 142.8 Main stem Velocity 850 150 Co nti nuous 143.6 Main stem Velocity 550 20 Discontinuous Mains tern Vel oci t y 280 20 Continuous 143.8 Main stem Vel oci t y 780 100 Continuous 143.9 Main stem Velocity 500 30 Co ntinuous 144 .5 Mainstem Veloci ty 900 100 Disconti nuous S lough (22) Therma l 250 20 Continuous 144 .6 Slough (2 2 ) Thermal 300 20 Continuous 145.5 Mains t ern Velocity 1 '150 100 Conti nuo us 146.9 Mai n stem Velocity 700 100 ,Conti nu o~s 147. 1 Main stem Velocity 850 80 Disconti nuous 147 .7 Ma in stem Veloci t y 150 40 Continuous 148 . 1 Main stem Ve locity 42(, 50 D i scontinuous 148 .5 Main stem Velocity 680 140 Continuous 149 0 Mai n stem Ve l ocity 400 60 Contintwu s 149 .5 Main stem Ve l ocity 500 80 Conti nuc us 150 .0 Main s tem Ve loci t y 350 20 Di sco ntinuous 150.2 Main stem Ve l oci t y 750 100 Conti nuous 151 .2 Mai nstem Ve locity 2 ,800 100 Discontinuous (1) Veloci ty i nd i cates lead kept open b y high -veloc ity fl ows . T hermal i nd icates le~d ke1=t op en by groundwater seepage . 70 -1 ..... on ao 62 ~(I) ~c :~ ~)) !z =~ .. !!! c ~ • c -~2 go .. "'" ~· co c .. ell ~ • ~ ~~ ~~\:::' ~ 1.:::: ' . 0 11 ~lRli "'"i ~ ~~ ~ t;.l~ "'"i~ ~~ Ill!.§ -0 0 - w a: ::;) .... ct a: w a. ~ w .... a: -ct >- ..J -c( 0 z < w ~ 10 8CE CONCENTRATIONS AT TALKEETNA RELATIVE TO MEAN DAILY AIR TEMPERATURES AT DENALI AND TALKEETNA AND DAILY TOTAL SNOWFALL AT TALKEETNA of ' ~~Talk••:• --w -10 I I -20 ( - -Ice concentration percentage of channel aurfaca coverage I --mean dally air temperature at Denali I (367 freezing degree daya In October) -mean dally air temperature at Talkeetna I (170 freezing degree daya In October) I -30 0 total snowfall at Talkeetna (mm) I I J 1-r -e e I !\ I e .... o '-I -40 -1- Q I ... -"?"' n e I e e Ql ~ I ,.. e I e 0 -50 I ''-.! I I I I I r. 10 210 f100 freeze-up~ ,~ I I ao T J I +so I l 1_40 I ~--~ ~ I T2o J e e I ~ • 0 OCTOBER NOVEMBER -?f. - z 0 -.... ct a: .... z w 0 z 0 0 w 0 ~~~~p ;s "(J, • on oO g2 ii Ul ~c '~ 0> ;z .... .m C• I c -~2 ~n .. "" -co c: -..J .. IV • ~ . It\) § ib ~ ~ .&.;:: Cs II ~!Rli ..... ~ ~~ ~~ §~ ,.,(§ -0 0 - w a: 10 0 ::) -10 t- <t a: w 0.. ::i w t- a: -ct -20 ~ -30 -< c z <( 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 c overage -mean dally air temperature at Devil Canyon 0 total anowfall at Gold Creek (mm) freeze -up '-... I ~'""' I I I I f I \I I ~ \ I \I \ e e EIO eiO .... 0 (I') .... I I I I r 1 I I I ~\ I I ' f gl, I Ill I N~ \ I Ill I I Ill I \,I Ill I ~ l11/ ~ II \ \ I I I e\ ~I I I ~\ IJ I I N \ I I I \ 1 l I \I \ I ~ v \ \ I l ~ Ice at I r lr-Gold Creek 1! I I 1 I 1~ I\ 11 t\ r\ lnlq iJ \, I I 1 \~ I I I I \ I I I J ( I I ' I I\\ I ( AV I I I I I I I w -40 .. ~ ~~ ~ J ~ Snowfall at Gold Creek \ I I \J II I I 0 10 oe e 10E e 0 10 ~ r -100 I ~ I Teo~ J I - z 0 +60 t- 1 ~ l ~ 1_40 I -f w 0 z 0 0 I w T2o o J I _50 ,,,, ''''I''' ,,,, ,, 11 , 1 ''" , ,, •1 , , 0 October 19 -January 17 ~ w "" -(Q c .. G ~ • (,.) ~~ ~~ <...~ 0 u ~ ""i U1Fi ~ ~2§ ~~ ~~ Ill § ~ " > .! Ill 1, .. c: Ill Gl E " > 0 .Q Ill .. " • - z 0 ... "' > w _, w 800 ~:>O C 400 200 N N .. u 0 "' N -u 0 ... > N 0 ,. z g) 0 I v N z ::t .. I i ; u 0 I ~ 2 .1 Mtld .....-7 ml /d----+- ------12 mild I TALKEETNA' Cll > 0 z ... > 0 z 1.t lftl/d 2 .2 mild • .. c • tO~ 0 N ~ N I~ > 0 z .. "'''" \OOLD CREEK "----IHERMAN .,ILOUOH I "--ILOUOH I '\_CURRY \ \CHUU TNA-IUIITNA CONfLUENCE RAD IOE AUX CREEK~ ~ ,r IIAC H CRUK ILOUOH '-auNSHN \ "MONTANA CREEK \. OOOIE CREEK ILOUOH SU81TNA-YEKTNA \ CONFLUEKCE \ 0~--~----.---_.----.---------~--------~--------~--------~------~~------~ 20 40 60 80 RIVER MILE 100 120 140 SUSITNA RIVER ICE LEADING EDGE PROGRESSION RATES (miles /day) RELATIVE TO THE THALWEG PROFILE FROM RIVER MILE 0 (Cook Inlet) TO RIVER MILE 155 160 ;DI~o !!~ ~ ~~ ~ • aO ~0 c;z ~(I) :c ~4 n> !z =~ .m , .. ·-;z ~0 •• .,. -co c -...! ... ,. . ~ • ~ (/)I c::: . ~ b< ~ ). loi:' Cs II ~fti'l ""i ~ ~~ §@0 ~~ "'(§ -.... Q) Q) .:=. 3.0 ct ~ I 0) _, _, 2.0 w ~ ~ w ~ 1.0 .... CJ) a: \ \ \ \ ' \ \ \ \ \_"' STAGE FLUCTUATIONS IN GROUND WATER WELL 9-1 A (River Mile 129.5) RELATIVE TO MAINSTEM DISCHARGE '-, \ \~"\ \" '\ ' "-...... ................ ........ _ --'--"'-- --USGS dlachargea at Gold Creek --water surfa c e elevatloo In ground water well 9-1A end data~_ .. ··· ... ·. - -r-1 2,000 I l 1_10,000 1 0 .... -1 2 I en Ta,ooo ~ J ~ I 5 +6,000 I en -c l ~ w w 1_4,000 5 I c /-1 ~ '---._'""'r I (!) T2,ooo J '-leading edge of Ice cover 1 progreaaea paat well loc ation UJ .... ct o ' I I I +-Lo 3: . OCTOBER NOVEMBER DECEMBER I MONTH !~~~~ ~~ r~ ? o n ·~ "0 ~2 :;(I) ~c ~~ D:i ;z , .... ,(1) c . D ~2 go ..... .,. -ca c ~ ~ Vl • ... • "' ~ &~(,.;: -1;: ~ ~~ .._ t'- 0 11 ~r.:;.-. '1~ ~~ <:@:e) ~~ Ill <§ TlME__LAPSE CAMERA . LOCATIO.H AT .. DE .. YLL. CANYON .PROP-OSED DAMSJT.._.e ___ J ~ \ . -;-. ! . ~ -~ . ·;-. .I -·, -: · · · . I : ! ... : i : I i i · : ~ """ • . . ' ' • • • • ' ' ' ' ' • • g •· ; ' ~ I ... r' . ~. ~ . ~: . ~ , . ~ ~--:· ~· ---; -:--r -.. ! -l : -, j ~ . J ; • . 1 L :_ -----~ :__ _ .. _. ~ ~-~ .;_ . -~ -----".. ~ ·---·----I L --" --~-~ l . . r--·---------------~ ---------n · •-~ ----I ---------T I , -l ...;::.:. -==-r I~ I'-J i T--r-· ! i 1 -:··--:-TT --: .. :-·r--I:-· -----+-~·_t ~·oo2!2U:u_:__l -· -. 1 ! .. ~-. .·· . 0 r.. -6..0 (. , "' 820 ~ 600 ....... I I ,--·:-·-~· .,. : ••. : • . / i . . ~. . i I . . . ...... ' • .. · .. :· I I --1 . ~~J . ~ Horizontal: 1• = 800' Vertical: 1• = 30' . -BOT T O M , { ---W4Ttloflt ~#IC.tr:'A G &' ! ~ Jf/MI ----· &Dt:~ O il u:• • -· --1 0P O' IG£ A T SUOR C _ _ WAT.,. .S <.HV 'ACI!! .~IZ.IWJZ ( _ ...... n:w"" or /Cl! 7 · 7 1-u V t.' PHOTO 4.1 Frazil ice discs collected from floating ice pan. PHOTO 4.2 S u sitna River at Go ld Creek on· October 16, 1982, looking downstream from the railroad bridge. Note the frazil s lu sh floes and shore ice development. ~ &M :::ONSULTANTS, IN:::. aNGI NaCRS OCOL.DCI!JT!i P'"-ANNe-IJ'tS S UAVC.VD.S SUSJTNA JOINT VENTURE 76 PHOTO 4.3 ·_, }_ -~ Shore ice constriction near Slough 9 on October 26 , 1982 . Flow i s from r ig ht to left . Note the successive layers of slush ice that have built up along the left bank. Slush ice is being compressed throug h the surface constriction , emerging on the left as r afts. PHOTO 4 .4 Slush ice accumulating by j u x ta position on October 29, 1982 at Sunshi ne . Flow is from left to rig ht . This area represents the l eading edge of an ice front that has just p assed the Park s Highway Bridge . Note t he fl ooded side cha n nel in th e upper photo . The ice pack has caused a loca l i ncrease in water level of about 2 feet . R&M CONSULTANTS, INC. •NOIN•a•a O&OLOO,aTa PLANN.Aa av•vavo•a 77 SUSI TNA J OINT VENTURE I Border ice growth . low-velocity region collisions by floating PHOTO 4.5 The smooth areas are black ice or snow ice formed in the along the shore . The layers of ice are caused when ice p a n s deposit frazil ice along the edge . PHOTO 4.6 Hummocked ice at river mile 103 , formed by the accumulation of slush , ice floes, and snow which progresses upstream during freeze-up . R&M CCNSUL.TANTS, INC. eNGIN···· OaOLDDI•Ta •'-ANNe•• au .. vavo•a 78 SUSITNA JOINT VENTURE PHOTO 4.7 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 4.8 Anc hor ice dam formed at river mile 140 , between Indian River and Portage Creek. Ancho r ice has f o rmed on the rocks due to attachment of frazil ice . R&M CONSULTANTS, INC. .NOtNa .... a a•O\.OCitWTa ~ANN••• au"v •vo•a 79 SUSITNA JOINT VENTURE .. PHOTO 4 .9 Sample of ice taken du ri ng breakup at river mile 142. Den~e concentrations of anchor ice were observed through this reach during freeze-up . This ice had accumulated sediment by filtration and entrapment of saltating particles . -. -~ ·~ -:.: ::.; ,.. ··--s.J --. -. ---...... - PHOTO 4.10 Slush ice bridge at river mile 10 on October 26, 1982. Th is ice bridge is the key to upstream progression of the ice cover up the lower Susitna Ri v er . The bridge forms when large vo lumes of ice d ischarge are unable to pass through the river bend. R&M CONSULTANTS, INC. •Nau-.•••"• a•o~oa•aTa ~ANN8Aa au•vavo•• 80 SUS/TNA JOINT VENTURE •• s_zu ----... ·-.. P HOT O 4.11 Confluence of Montana Creek and Susitna Riv er , October 29, 1982 . T 1e ice cover progression caused staging of about 4 feet, demonstrated by the wa ter backed up at the tributary mouth . PHOTO 4 .12 Leading edge of ice cover at r ive r mile 95 on November 2, 1982 . fl-{]f)JW &J IE fBi!~~® SUSITNA JOINT VENTURE c:;&M =oNSLJLTAI\!TS, INC. .NOfNaeaa OCCLD0t8 T a PLANN.AS SuavevOA 8 81 • • I I I PHOTO 4.13 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 pass ed Talkeetna . By November 7, this areas was covered by 4 feet of ice . PHOTO 4.14 View of the mainstem, a djacent t o the t own of Talkeetna , on November 4 , 1982. The ice fro nt has prog ressed to w ith in 1 mile of this area , and caused the water lev el to inc r ease o ver 2 f eet. The s h ore ice i n the foreground has fri:lgmented and wi ll eventually was h awa y . R&M CONSULTANTS, INC:. aNOIN•••• aaoLooeeTa •~o..aNN•A• a u •vevo•• 82 ~ll f:'ITAIA ,,.. ..... -· ·-· ~. ·--:_ '- PHOTO 4.15 Susitna-Chulitna confluence, looking upstream on October 18, 1982. The slush ice was sti ll moving easily through this area . The Chulitna east channel is e ntering from the left. PHOTO 4.16 View of the Chulitna confluence with the Susitna mainstem, looking upstreaM on October 29, 1982 . The Chulitna west channel enters in the left fo reground, the east cha nnel comes in on the upper left, and the Susitna River flows diagonally f rom the center to the right margin . Note the slush ice accumulation at the east channel. R&M CONSULTANTS, INC. aNO•N•••• a•a~oa••T• •\..ANNa~~t a au•vavo•• 83 SUSJTNA JOINT VENTURE Susitna River confluence with view looki ng downstream on confluence has consoli dated subsequent flooding. About channel . PHOTO 4.17 the Chulitna east channel on November 2, 1982, the Susitna. The slush ice constriction at the and frozen , creating this jam and causing 1000 cfs is being diverted into the Chulitna east PHOTO 4.18 Looki ng downstream at leading edge at river mile 106 near Chase on November 9 , 1982. The ice cover was stagi ng to overcome high velocities at the leadi ng edge. However, water flowed into the side-channel at left , preventing extensive backwater development until the side-channel filled with ice. R&M CONSULTANTS, INC. 8NOtNae•• GaOL0018Te •LAN .... eA8 SUtltVAYO•s 84 SUS/TNA JOINT VENTURE ----------- PHOTO 4.19 Ice cover at Slough SA on March 14, 1983 . The steep-walled channel in the center is between consolidated slush ice . Staging had caused large volumes of slush ice to be swept into the slough, which developed slush ice thicknesses of 5-6 feet. PHOTO 4.20 Susitnd River at Gold Creek on January 13 , 1983 . constricted the water surface width to less than 50 ice cover progressed past Gold Creek on January 14 . R&M CONSULTANTS, INC. aHOIN..... 0•011..001aT8 Dl,.ANN.A8 SUIIIIIV8VO .. S 85 Shore ice development has feet under the bridge. The SUSITNA JOINT VENTURE PHOTO 4.21 Susitna River at river mile 106 on November 17 , 1982. Flow is from the upper right to lower left. Ice cove r has telescoped to cover the river channel frorr. bank to bank . Note the sagging ice cover over the narrow winter channel anc the open leads created by turbulent flow. PHOTO 4 .22 Open leads on February 2 , 198 3 at rive r mile 103 .5 , vi e w looking d ow nstream . Note the slush ice cover developing in th e foreground . [J{Jj)jW u IEI:Jffil~~® SUSITNA JOINT VENTURE R&M CONSULTANTS, INC. eNO•N•••• aao~oat•T• •l..ANN••• auAv•vo"• 86 PHOTO 4 .23 Anchor ice dam or sill at river mile 140 on December 15 , 1982. These dams form when the r ocks to wh ich the frazil ice adheres are near the water surface . The ice-covered rocks will continue accumulating additional layers of anchor ice until they break the surface. PHOTO 4.24 Ove rflow onto border ice caused by an anchor ice dam . Fl ow is normally from upper left to lower right. The backwater effect of the anchor ice dam has caused some water to be d iverted to the left o n this photo. ~&M CONSULTANTS, INC. •NOIN.aA8 QeOl..OCISTS Pt..AN,.,.AS S UftVr;VOA S 87 SUSITNA JOINT VENTU.q£ ' ) .. ~ . I ./· PHOTO 4.25 Time lapse camera mounted on the south rim of Devil Cany0n near the proposed damsite. This camera filmed the ice cover development in the canyon from October 21 , 1982 until February 7 , 1983. PHOTO 4.26 Ice bridge in Devil Ca n yon on October 21 , 1982. Th is closure represents the first ice cover on the Susitna above Talkeetna. Flow is from left to right. Th e initial constriction by shore ice is still evident. The channel has a shallo w gradient , with a gravel bar o n th e right bank and a deep narrow thalweg along the left bank. R&M CONSULTANTS, INC. .NOINae•a OaOL00$8T e .. LANN.RS au•v•vo•• 88 SUS/TNA JOINT VENTURE PHOTC 4 .27 Ice cover in Devil Canyon at river mil e 151 on October 26, 1982. t hickness along the shore is about 4 feet and will eventual ly thi cken to feet . Fl o w is from lowe r left to upper right. PHOTO 4 .28 The ice cover 15 Extensive shore ice development near the confluence of Devil C reek . Fl o w is from left to right . Sho r e ice had built o ut in successive layers to constrict the channel unt il sl-ush ice could n o lo ng er fl o w through . R&M C:CNSUI'-TANTS, INC. IIN OI,_..... a •OLOOtaTa P \.ANN.Aa S UAVa..,OIII S 89 SUSITNA JOINT VENTURE s6/jj 1 5 .0 SUSITNA RIVER BREAKUP PROCESSES Destruction of a r1 ve r ice cover progresses from a gradual deterio ration of the ic e to a dramatic d isintegrat io n which is often accompani ed by ice jams , fl ooding, and erosion. The duration of breakup is primarily dependent on the intensity d solar radiation , ai r tempe rature , an d the amo u n t of rain - fall. An ice cover will rapidly break apart at high flows . Ice debris accumulates at flow constriction s and c an become grounded . The final ph ases o f brea kup are cha racter i zed by long open reaches separated by massiv e ice j ams . A la rge ja m releasing upst ream will usually carry away the remain i ng down s tream debris leaving the river channel virtually ice free . 5 .1 Pre-Breakup Period Breakup processes on the Susitna River a r e similar to those described for other n o rthern ri ve rs , with a pre-breakup period , a drive, and a wash (Michel , 1971). The pre-breakup period o cc urs as s nowmelt begins due to increased solar radia t io n in early April. This process generally begins at the lower elevations near the mouth of the Su si tna River, working its way n orth. By late Ap ri l , the snow has gene ra lly d isappeared from the rive r south of Talkeetna and has started to melt along the r iver a bove Talkeetna . Snow o n the ri v ~r ice generally disap pears before that a long th e ban ks, ei ther due to overflow or because the snowpack is simpl y thinner on the river due t o exposure to w i nds. Overf low takes place because the rigid and impermeab le ice cove r fails to r espond to water level fluctuations (Table 5 .1 ). Where th e ice is continuous a nd unbroke n , stan ding water commonly appears i n the sags and depres s ion s . Th is water substant:ally reduce s the ;•lbedo o f the ice s urface. Wi thin d a y s , a n open water lead develo ps in these depressions . With water levels steadily rising, the chan n el p eri meter 90 s6/jj2 expands , initiating undercutting of the stranded ice . This causes portions of the ice cover to hang over the open lead . When the critical shear stress is exceeded , portions of the ice.. cover collapse by either hinging at t h e p oin t where it con tacts the rive r bottom or else by shearing v ertically f rom the main ic e body . The ice fragments then drift downstream to accumulate with other f loes against the solid ice cov er at the d o wnstream edge of the lead (Photo 5 .1). By this process, open leads gradually become wider and lon ger . The high velocity reaches in which most leads form are more common above Talkeetna because the river channel is relati v ely narrow , lac k s a wide flood plain , and has a steeper grad ient . Downstream fro m Talkeetna, the broad and shallow river channel has a lower gradient, tend i ng to reduce v elocities by d is tri buting the flow o ver a wider area. Here open leads occur less f requently, with extens ive overflow being the first indil-dtor o f r i sing water levels. On April 7, 1983 , an area of overflow near the Pa rks Highway Bridge covered the ice sheet with ove r 6 inc hes of fl ow ing water (P hoto 5 . 2). Solid and contin uou s ice covers can fragment en masse when the pressure created by the rising water level can no longer be con- tained . This was especially true o n the lower river downstream o f Talkeetna. The shattered ice cover, howeve r, may rema in in place for severa l days if the ice downstream remains i nt;:,ct. By the end of Apr i l , 1983 , the Susitna R:ver was laced with long, narrow open leads . Floes that had fr7.~gmented from the ic e had accumulated into small ice jams. The configuration o f these small ice jams o ften resembled a U o r V-shaped wedge, the apex of the wedge corresponding to the highest velocities in the flow distribution . The cons ta nt pressure e x erted by these wedge-shaped ice jams effectively lengthens and widens many open leads, 1·edu ci ng the p o tential f o r major ice jams at these points. 91 s6/jj3 5 . 2 Breakup Drive The drive , or the actual downstream breakup of the ice cover , o ccurs when the discharge is high enol.!gh to break and move the ice sheet . The intensity and duration is dependent on meteorological conditions during the pre-breakup period. Both weak and strong ice drives have been observed on the Susitna River during the last 3 years . In 1981, there was a mi nimal snowpack and only light precipitation during spring . Air temperatures were warmer than normal in early spring, but returned to normal in April , resulting in slow melting of what snow there was . Consequently, there was not a sufficien t increase in flow to develop strong f o rces on the ice cover, and the ice tended to slowly d isintegrate in place . Although some ice jams did occur during the drive , they did not tend to last long , and the breakup was generally m ild. Conditions were rev ersed i n 1982 . A heavy snowpack remaining i n late April and temperatures slightly cooler than normal prevented weakening of the ice . The ice remained sufficiently strong to cau se several severe jams. Near RM 128 bebw Sherman , a dry jam formed which diverted most of the flow out of the mainstem into side chan- nels . Closer to Talkeetna , a jam f o rmed at RM 107 that lasted for 3 days , jamming ice for o v er a mile and damaging sections of the Alaska Railroad track. Jam s ites gen erally have similar chan nel configuratio ns , consi s ting of a broad c hanne l with gravel islands o r bars , and a narrow , deep thalweg confined along one of the banks . Sharp bends i n the river are also good jam sites . The presence of sloughs on a river reach may indicate the locations of frequently recurring ic e jams . Many of the s lo ughs o n the S usitna River between Curry and Devil Canyon were c a rved t h r o u g h terrace pl ai ns by some e xtreme flood. Summer floods , although frequent ly flowing th ro ugh sloughs , do not gene ra lly result in water levels high enough to ov ertop the r:ver ban k. 92 s6/jj4 During b r eakup , however , ice jams commonly cause rapid , local stage increases that continue rising until either the jam releases or the sloughs are flooced . While the jam holds, channel capacity is greatly reduced, and flow and large amounts of ice are diverted in to the trees and side-channels. The ice has tremendous erosive force, and can rapidly remove large sections of bank. Old ice scars up to 10 feet above the bank level have been noted along side-channels near this reach . It appears that these sloughs are an indicator of frequent ice jams on the adjacent mainstem , influencing the stability and longevity of these jams by relieving the stage increases and subsequent water pressures acting against the ice . In May of 1976 dur i ng 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 5 .3 is a photog r ap~, taken from the Gold C reek railroad bridge on May 7 , 1976 , showing a substa ntial volume of water flowing through Slough 11 . The ma instem and bypass chan nel are towards the right of the photo and appear to be completely ice choked. Local residents have indicated that this event created most of Slough 11 . Several ice jams of smalle r magnitude since 1976 have also breached the berm at the channel head and enlarged the s lough to its present configura- tion. The follow i ng chan nels between Devil Canyon and Talkeetna, are regularly infl u enced by ice-ind uced flooding duri ng 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 8A and 8 Slough 7 93 s6/jj5 In general , the f in al destructi o n of the ice cover is accomplished by a s e ries of ice jams wh ich break 1n succession and are added t o the nex t jam . This mass o f ice continues buildi ng as it move s down- stream . Upst rea m from this accumu latio n , the river channel i s com- monl y ic e free except for stranded ice floes and some drift ing ice c o mi ng from above Devil C an yon. Ice studie s during the 1983 Susitna Ri ver breakup were primarily ori e nted towards acq u i ring ice jam profi les on the river reach between Tal k eetna and Devil Canyon as well as quantitative data on ice thick- nesses, staging , and i low velocities (Fi gure 5 .1 and Tables 5 .1 to 5 .4). Bel ow Talkeetna , the use of loca l observers and aerial recon- na is sa n ce flights resulted in information on the sequence of brea k up in the lower Susitna R ive r . Measurem ents were initia lly takeP tw ice da i ly at specific sites above Talkeetna known to be affected by ice jams . Water surface elev a- tions , ice thi cknes s es , an d ice cover erosion rates were measured through b o re holes. Velocities in the mainstem abo';e and below ice jams were successfully measured by suspendi ng an electronic sensor with 30 feet of wire cabl e fro m a heli copter and obtaining a spot reading at 2 feet below the wate r surface. The water depth both above and b elow jams was a lso often measured by r ead i ng the depth d irectly from metal flags attached to the cable which was k ept vert ical wi th a 50 lb . lead weight . Wit h the exception of water depth , these d ata are presented i n T a ble 5 .1 . Residents at Susitna Station , the Deshka Ri v er coi1f luen c e , and Gold Creek p r o v ided measurements of water levels and ice thick nesses as well as qual itative desc ri ptions o f the seq uence of events lead ing up to ice-out . Weekly aerial reconn ai ssance flights were cond ucted in order to document the interrelationship betwee n river reaches . Tables 5 .1 t o 5.4 at the end of th is sectio n present all pertinent information. The follow ing de- sc r iption is a chronological sequence o f breakup even ts . Breakup o n 94 s6/jj 6 the lower Susitna is f i rst d e s cribed , f ollowed by t h e d escri p tio n o f brea k up events above T alk eetna fro m A p r i l 27 to Ma y 10 , 1983 . The major streams flow i ng d i rectl y i nto the lo wer Sus it n a Riv er we r e c o ntributi ng substantial disc harg es by April 27 , 1983 . The ice was i n varying stages o f decay o n these tributaries , with Ka s hwitna C r e e k retaining a virtually intact ice c over , and Montana C reek , Sh e ep Creek , and Will o w Creek breaking up rap idl y . By A pril 28 , t h ere was an o pen c hannel for mo st o f t he reach b e t ween Ta lk·!etna and the Parks Highway Bridge . Observ ation during an ae rial r ~co nna i ssance on Ap r il 29 d o cumented a rapidly d i sinte grati ng main s t ,~m ice cove r from Talkeetna down t o the Mo n tana Creek co nflu ence . Further downstream , the mainstem ice cover was ex tensively flooded but remained i ntact . Above t h e Parks Highway Bridge the ice cover had shattered into large ic e sheets i n several areas . these fra g ments h o wever , prevented the ice from Sunshine , an ice cov ered reach was fl ooded by The large s i ze o f flowing o ut . At about 0 . 5 feet o f overflow and y e t r e ma ined intact . No ic e jams had occurred . Observers at Susitna Station r epo r ted ice begi nning to move down - stream on May 2 w ith flowing ice conti nu i ng to pass fo r several da y s (Table 5 .2). Desh k a River resi den ts o b s erved the fi rst ice mo v ing o n May 4 and the steady ice flows ending on Ma y 10 (Table 5 .3). No significant j ams were note d. This indica tes an ups tream prog r essio n o f ice brea k up wh 1c h c onfi rmed the aeri al o bserv ations o n th e r iver below Montana Creek. The largest ice jam observ ed on the lower r iv er o ccurred on May 3 near the confl uen c e w ith Mo ntana Creek at RM 77 . Here an e x tensi v e acc umulation of drifting ice debr is h ad fa i led t o pass around a ri v er bend and jammed (Photo 5.4). The Montana Creek confluen c e was f looded but n o damage o r s ig n if icant impact by ice or water was noted . 95 s6/jj7 On May 4 , 1983 , two relati v ely small ice jams formed at RM 85 .5 and RM 89 . The j am keys were small b ut even the minimal stagi ng that resulted caused extensive flooding of the surrounding gravel and sand flood plain. Many logs were set adrift that had previously been stranded after high summer flows. On April 27 , 1983 , daily observations and data acquisition began upstream of Talkeetna. By th is time, the river had opened in some areas by the downstream progression of small ice jams (Photo 5 .1). These minor ice floe accumulations r emained on the water surface, often breaking down any intact ice cover obstructing their passage . As described earlier , this process is ini tiated in open leads wh ich gradually become longer and wider u ntil extensive reac hes of the channel are essentially ice free . These sma ll ice jams may be impor- tant in preventing the occurren ce 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 constricted. On April 27, extensive channel enlargements and small ice jams were steadily progressing downstream near the following locations: Portage Creek, RM 148.8 Jack Long 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 also developed near Lane Creek at RM 113 .5 and was apparently grounded. Flooded shore ice surrounding the j am indicated that some water had backed up . A noticeable increase in turbidity occurred on this day. 96 s6/jj8 On May 1 , the ice jam key at Lane Creek had shifted down to RM 113 .3 and was still accumulating ice floes at the upstream en d . The source of the floes was limited to fragmen ting shore ice and no sign ifica nt accumulat io n would occur here unt i l ice jams further up- stream released . The ice jam near Slough 2 1 had increased in size and was ra isi ng the water level along the upstream edge . This backwater extended approximately 300 feet upstream. Figure 5.1 -;hows a relative stage increase at this measurement site of over 3 feet in 24 hours , i llust r ating the water profile before and after this ice jam occurred. By May 2 , 1983, several large ice jams had developed. The small ice jam at Gold Creek had broken through the retaining sol id ice s heet , forming a continuous open channel from RM 139 near Indian Ri v er 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 141. A large jam had developed at RM 141 . 5, leaving an open water area between \ e two jams. The upstream ice jam was apparently created when a massive ice sheet snapped loose from shore-fu st ice and slowly pivoted out into the main stem flow, maintaining contact with the c hannel bottom at the downstream left bank corner . The ice sheet was ap- proximately 300 feet in diameter and probably between 3 and 4 feet thick. The upstream end p ivoted around until it contacted the right bank of the mainstem . The ice sheet was then in a very stal ~ position , jammed against the steep right bank and grounded in shal- low water along a gravel island on the left bank . Several small ice jams upstream had released and were accumulating against this ice sheet , extending the jam for about o ne-half mile . The water level r o se, with an estimated 2,000 cfs flowing around the upstream end of the g ravel island at RM 142 into a side chan nel. Th e entrance berm to Slough 21 at cross section H9 was also overtopped . Although the estimated discharge at Gold Creek was less than 6 ,000 cfs based on a staff gage reading, the normal summer flows required to breach this 97 s6/jj9 berm exceeded 20,000 cfs. The entrance channel at cross section A5 was breached, with abou t 150 cfs being diverted into the lower p ortion of Slough 21. Many ice floes also dr ifted through this narrow access channel and were grounded in the slough as the flo w was distributed over a wider area . This illustrates the extreme wate r level changes caused b y ice jams . By May 4 , 1983 , stable ice jams had developed and were gradually growing i n size at the f ollowing locations between Talkeetna and Devil Canyo n: Lane Creek at RM 113 .2 Curry at RM 120.5 and RM 119 .5 Slough 7 at RM 122 Slough 9 at RM 129 Sherman Creek at RM 131 .4 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 open and ice free with the exception of some remnant shore ice . From C urry upstream to the ice jam adjacent to Slough 7 some p ortions of the ice cover remained , but wet~e 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 cove r had many open leads and large areas o f fl ooded snow . Between the remaining ice jams at Sherman, Slough 11 and Slough 2 1 , the mainstem was essentially C"?en. The jam at S lough 21 was still receiving ice floes from the dis i nte - grating ice cover above Devil Canyon. As ice floes accumulated against the upstream edge of the jam , the fl oa ting layer became increasingly unstable. At some critical pressure within this cover, 98 s6/jj 10 the shear r esistance between floes was exceeded, r es ulting in a chain reaction of collisions that rapid ly caused the entire cover to fail . At this point, several hundred feet of ice cover consolidated simulta- neously. These consolidation phases occurred frequen tly duri ng a 4 hou r observat io n period at Slough 21 on May 4 . The frequ e ncy was dependent on the volu me of i n coming ice f loes . Wi th each consolida- tion , a surge wave resulted . During one partic ular consolidation of the entire half-mile ice jam , a surge wave broke loose all the shorefast ice along the left bank and pushed it o nto an adjacent gravel island . These blo cks of shore ice were up to 4 feet thick and 30 feet wide . The zone affected was almost 100 feet long , with the event la sting o nly a few seconds. This process is essentia lly the same as telescop ing during freeze -up except that the ice is in massi v e rigid blocks instead of fine frazil slush , and is thus capab le of erod- ing substantial volu mes of material in a very short time (Photos 5.5 , 5. 6). The ease with which these ice blocks were shoved over the river bank indica tes the tremendous pressures that b uil d within maj or ice jams . During all of the obse rved consolidations at Slough 21, the large ice sheet forming the key of the jam never appeared to move o r shift . The surge waves would occasionally overtop the ice sheet , sending smaller ice fragments rushing over the surface o f the sheet. Towards the end of the day , the ice sheet began to deform . Solar radiation , erosion and shear stresses were rapidly deteriorating this massive ice block . Final observations sh owed 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 . Taking into account the travel time , this indicates that the jam had probably released 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 s udden influx o f ice displaced the mainstem wate r and caused a 99 s6/jj 11 rapid rise in water levels. The stage increased sufficiently to breach berms and fl ood the side channel below Slough 11 adjacent to mainstem ri v er mile 135. The jam key at this site consisted of shorefast ice constricting the mainstem flow to a narrow channel of no more than 50 feet . Large ice floes , mostly from the ori ginal jam at Gold Creek, had lodged tightly in this bottleneck. Pressures appeared to be exerted laterally against the shore-fast ice which inherently is res istant to movement due to the hig h friction coefficie nt of the contacting river bed substrata. 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 main stem. It was at first thought that when the ice broke at Sl o ugh 11 on May 6 (Photo 5 . 7), 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 spu n out into the mainstem. One triangular ice sheet about 100 feet w ide wedged tightly between two extended sheets of shore-fast ice (Photo 5 .8). Ice floes continuing to accumulate against the upstream edge of this wedge exerted tremendous pressures o n the o bstruction (Photo 5. 9). A pressure ridge rising at least 10 feet above the ice formed along the contact surfaces of the wedge (Photo 5.10) .. Th is 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 (P h o to 5 .11). Flooding quickly 100 s6/jj 12 occurred on the side channels adja cent to the mainstem and some ice drifted away from the main cha nnel. The volu me 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 i ncre ase d in size, any additional hydrostatic pressure was relieved by diverting water into the side cha nnels. The entire sequence of events lasted only about 10 to 15 minutes. The water level rose over 1 foot during this time span . Consolidations occ urred periodically for the rest of the day but the jam key was never observed to shift . Other maj or ice jams keys on May 6 were located at : Watana Oamsite Sherman Creek at RM 131.5 Slough 9 at RM 129 Slough 8 near Skull Creek at RM 124.5 Slough 7 at RM 122 Curry at RM 120 .5 (Photo 5.12) Lane Creek at RM 113 A small and unstable ice jam at RM 126 near Slough 8 had consolidated and the resulting surge started a rapid disintegration of the remaining 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 flooded by a jam at RM 129 near the upstream channel entrance . The Slough 7 ice jam received some additio nal floes when the jam at Slough 8 released. This resulted in a rise in water level and flooding at RM 123 . At 6:30 p .m . on May 6, a moving mass of ice debris that stretched continuously from RM 136 to RM 138 , with lesser concentrations 101 s 6/jjl3 extendi ng for many more miles upstream , was observed approaching the Shetlllan ice jam . However , the consequences of this on the Sherman jam •vere not immediately observed. The condition of the floes indicated t hat this ice origi nated from above Devil Canyon. The well -rounded floes appeared to be no larger than 1 foot i n diameter and were p r esumably 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 ma instem enti rel y clear of an ice cover for many miles. Stranded ice f loes and fragments littered the river banks up to the confluence of Fog Creek . In several short reaches f rom here upstream to Watana, the ice cover r e mained intact. A large jam had developed near the proposed Wata,a damsite and extended approximately 1 mile (Photo 5. 13). On May 7, the following ice jams persisted : Key Location Watana Damsite Sherman , RM 131 .5 Slough 7, RM 122 Slough 6A, RM 11 2.5 (formerly Lane Creek jam) Length 1 mile 3 .5miles 1 mile 2 miles Downstream from the jam at Slough 6A, the rive r retained an inter- mittent ice cove r that was severely decayed a nd flooded. Below the Chulitna confluence , the mainstem was ice free an d no ice jams were observed. The reaches between the remaining ice jams were generally wide open. The Curry jam had release d overn igh t and traveled all the way t o the Lane Creek jam . Here , the sudden increase in ice mass shov ed the entire ice jam downstream about 1 mile where it again encountered a solid but decayed ice cover. 102 s6/jj 14 At about 10:30 p.m. on May 8, the ice jam at Sherman released (Photo 5 .14), 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 S lough 7 and Slough 6A . In addition , the last solid ice cover between Slough 6A at RM 112 and the Susitna-Chulitna confluence at RM 98 .5 was destroyed and re- p1aced i.."'Y one long , massive ice jam (Photo 5 .15). This jam extended continuously from RM 99.5 to RM 104 and then was interrupted by an open water section up to RM 107. At this poi nt a second ice jam resumed upstream to RM 109.5. This blockage was late r measured t o be over 16 feet thick in some sections but more commonly was about 13 feet th ick . 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 o n the river banks, lea ving ice fl oes deep in the fores t (Photo 5. 16). When the ice jams released, the ice floes pi led 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 shea r stresses were relieved (Photo 5. 17). The main body of the ice jam flowed downstream leaving stranded ice deposits w ith smooth vertica l walls at the edge of water. These shear walls at RM 108.5 were 16 feet h ig h (Photo 5.18). 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, thP o nly remaining ice in the main stem was on the upper river above Watana. Here an ice jam about 1. 5 miles long had devel- oped near Jay Creek. 103 s6/j jl5 Ice floe s continued to drift d o w nstream for several weeks after the f i nal ice jam at Chase rel eased. As increasing d ischarges gradually raised the water level , ice f loes 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 intact near Whiskers Creek and probably would n o t be washed away u ntil a h i gh summer flow. The ice break up of 1983 occurred over a longer time span than in previous years , according to historical informatio n and local resi- dents . This was primarily due to the lack of precipitation during the c ritical period when the ice cove r had decayed and co uld have been easi ly and quickly destroyed by a sudden, area-wide stage increase. During a yea r with more precipitation in late Apri l , ice jams of great- er magnitude ma y form and cause substantially more flooding and subsequent damage by erosi o n and ice scouring. Sev e r al important aspects related to 1ce jams were obs erved this year and are summarized here : 1. Ice jams generally o cc ur in a reas of si milar channel configura- tion, that is , shallow rea c hes with a narrow confined thalweg channel along o ne bank . 2. Ice jams commonly occur adjacent to side channels or sloughs . 3. Sloughs act as bypass channels during extreme mainstem stages, often relieving the hydro static pressure from ice jams and con- trolling the water le v el in the main channel. Ice jam flooding probably formed the majority of the sloug hs between Curry and Gold Creek. 4 . Ice j ams commonly c rt~ate surge waves dur i '1g consolidation which hea ve ice laterally onto the overban k. 104 s6/jj16 5. Large ice sh eets can break loose from shore-fast ice and wedge across the main stem c hannel , creating extremely s table jams that generall y only release when the ice deca y s . 105 s5 /gg 1 TABLE 5.1 WATER STAG E AND R IVER ICE THI CKN ESS MEASUREMENTS AT SELECTED MAINSTEM LO CA TIONS Water Ice Surface Top of Ice T hicknes s Ele v ation 1 Elevation 1 Velocity3 (ft) (ft) (ft) ft/sec Aeril 271 1983 Gold C reek Di scharg e : 2 Observed = 4300 cfs USGS = 2700 cfs Portag e Creek 832 .54 5 .2 Slough 21 I LR>:-57 749 .69 755 .5 2 .1 Slough 21 I LRX · 54 3 . 1 732.2 1 733 .3 2 .6 Gold Creek 682 .04 4.6 Slough 11 I Mouth [1 .11] [3 .3] 4.3 Slough 91 Sherman 6 17 . 18 1.1 Sl oug h 9 1 Mouth 2 .2 [5 .74 ] [5.7] Aeril 28 1 1983 Gold Creek Discha r ge : Observed 2 = 4100 cfs USGS = 2900 cfs Portage C reek 3 .9 834 .22 (+1 .68) 83 7.0 Sloug h 21 I LR X -57 4 .2 753 .03 (•3 .3) 754 .7 (-0.8) Slough 21 1 LR X -54 3 .0 (-. 1 ) 732.32 ( +. 1) 733.3 Gold Creek 681 . 94 ( -. 1) Sl oug h 11 1 Mouth [ 1. 26] (+. 1 ) [2 .2] (-1.2) Slo u g h 9 1 Sh erman 617 . 16 620 .1 S l ough 9 1 Mo uth 2 . 1 (-. 1) (5.57] (-.2) [5 .8 ] Slough 8 1 Head 5.3 3.6 Sl o u gh 81 LRX-28 55 2 .39 Curry 3 . 1 522 .46 524 .8 Mc Ken zie Creek 487 .92 493 .3 Lane Creek 2 .9 [ 4. 0 1] [4 .8] 3 .6 LRX -1 1 [ 1. 22] (5 .3 ] LRX-9 379 .3 2 383 .9 LRX-3 3 .7 34 1.00 342.4 106 s5/gg2 TABLE 5 .1 (Continued) Water Ice Surface T o p of Ice Thickness Elevation 1 Elevation 1 Velocity3 (ft) (ft) (ft) ft/sec Ae ril 29 , 1983 Go ld Creek Discharge: 2 Observed = 4100 cfs USG S = 3100 cfs Portage Creek 2 .8 833.04 (-1 .18) 834 .0 (-3.0) Slough 21 , LRX-57 3.9 753 .10 754.5 (-.2) 2 .4 Slough 21 , LR X-54 2.9 (-. 1) 732 .32 733 .3 Gold Creek 681.94 Slough 11, Mou th 1 .3 [1. 23] [2 .5] Slough 9 , Sherman 617 .29 (•.1) 5.4 Slough 9 , Mo uth 2.0 [5 .80] (+.2) [5 .6] (-. 1) Slough 8, Head 5 .0 Slough 8 , LR X-28 552.51 (+.13) Curry 3.0 522.64 (•.18) 524.8 McKenzie Creek 488 . 05 ( + . 13 ) Lane Creek 2 .9 [4 .18 ] (•.17) [4 .8 ] LR X-9 380 . 63 ( + 1 . 31) Talkeetna Airstrip [0 .55] Aeril 30, 1983 Gold C reek Discha rge: 2 Obse rved = 4325 cfs USGS = 3300 cfs Portage Creek 2.5 (-.3) 833.09 833.9 (-.2) Slough 21, LR X-57 4 .0 ( +. 1) 753.74 (+.64) 754 .52 2.8 Slough 21 , LR X-54 2.9 731 .51 (-. 8 1) 733 .2 (-. 1) 1.5 Gold Creek 682.05 (•.11) 3.6 Slough 9 , Mouth 1 . 8 (-.2) [5 .82] [5 .5 ] (-. 1) Slough 8 , Head --5.7 Lane C r eek 2 .9 [3 . 90] (-.28) [4 .8 ] 5 .3 LRX-11 [1.81] (-.4) LRX-3 3.6 343.43 (+2 .46) 343 .0 ( +. 6) 107 s5/gg3 TABLE5 .1 (Continued) Wa ter Ice Surface Top of Ice Thickness Elevation 1 Elevation 1 Velocity3 (ft) (ft) (ft) ft/sec Ma•t 1, 1983 Gold Creek Discharge : 2 Observed = 4700 cfs USGS = 3600 cfs Portage Creek 2 .1 833 .27 (•.2) 833 .4 (•.4) Slough 21, LRX-57 3 .9 752 .54 (-. 6) 754.4 (-. 1) Slough 21, LRX-54 2 .9 733.09 (•1.6) 733 .4 (•.2) Gold Creek 682 .20 ( +. 15) Slough 8, Head 6.5 Curry 2 .9 (. 1) 523 .21 ( +. 6) 524 .6 (-. 1) Lane Creek 3 .0 [6 .85] (•2 .95) [6 .6] ( +1 . 8) Ma~ 2, 1983 Gold Creek Discharge : 2 Observed = 5750 cfs USGS = 3900 cfs Portage Creek 2.2 833.63 ( +. 36) 833 .7 (•.3) Slough 21, LRX-57 3 .9 753 .02 (+.48) 754.5 Slough 21 , LRX -54 2 .8 731 .74 (-1 .4) 733 .1 (-.2) Gold Creek 682 .62 ( +. 42) Slough 8 , Head 8 .1 Lane Creek 2 .9 [6 .37] (-.48) [6.5] (-. 1) Ma~ 3, 1983 Go ld Creek Discharge : 2 Observed = 6180 cfs USGS = 4200 cfs Slough 21, LRX -54 2.8 (-.1) 731.91 (•.17) 733 .1 (-.3) S lough 11 , Mo uth [4 .88] (+3.65) Slough 8 , Head 9.6 108 s5/gg4 May 4 , 1983 Gold Cree k Discharge : Observed2 = 6180 cfs US GS = 4500 cfs Gold Creek Slough 8, Head May 5, 1983 Gold Creek Discharge : 2 Observed = no data USGS = 4900 cfs Slough 9, H9 berm Slough 9 , Sherman May 6, 1983 Gold C reek Discharge : Observed2 = 10 ,920 cfs USGS = 5400 cfs Gold Creek TABLE 5.1 (Continued) Ice Th ickness (ft) (breached) Water Surface Elev ation 1 ( ft) 682.78 (+. 16) 606 .51 620 .89 (+3 .60) 684 .15 (+1.37) 109 Top of Ice Elevation 1 (ft) Velocity3 ft/ sec 9.2 s 5 /g g5 May 10, 1983 Gold Creek Discharge : Observed2 = 14 ,350 cfs USGS = 5800 cfs Gold Creek TABLE 5.1 (Co ntinued) Ice Thickness (ft) Water Surface Elevation 1 (ft) 684 .97 (•.82) Top of Ice Elevation 1 (ft) Velocity3 ftlsec 1 . Values in brackets [ ] represent relative elevations based on an arbitrary datum from a temporary bench mar k adjacent to the site. Values in parenthesis denote the increase (•) or decrease (-) since the prev io us measurement. 2 . Observed discharges were computed from the U.S.G.S. stage/discha rge curve and are based on staff gage readin gs. The second "US GS" va lue is the provisional estimated flow obtained f r o m the US Geo logical Survey . 3 . Veloc ities represent measurements o btained at one point on a sectio n at a depth of 2 feet near mid-channel. 110 ~5/cc3 TABLE 5 .2 SUSITNA RIVER AT SUSITNA STATION BREAKUP OBSERVA TIONS ON THE MAINSTEM Staff Mean Air Gauge 1 Temperature 2 Ice Thickness Date illL (°C) (ft) Weather Apri l 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 C l oudy 30 11 .45 3.6 1.9 Sunny May 1983 1 6.4 Sunny 2 5 .0 Ice began moving Cloudy 3 6 .9 Ice flowing Cloudy 4 5.6 Ice f l owing C l oudy 5 5.8 Ice flowi ng C l oudy 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 C l o udy 12 12.5 Open C l o udy 1 . Relative elevation based on an arbitrary datum. 2. Average of the maximum and minimum temperatures. 111 s5/cc1 TABLE 5.3 SUSITNA RIVER AT THE DESHKA RIVER CONFLUENCE BREAKUP OBSERVATIONS ON THE MAINSTEM Staff Mean Ai r Snow Gauge 1 Temperature 2 Ice Thickness Depth Dati~ (ft) ( oc) (ft) illL 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 Su nny 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 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 24 2.40 7 .2 Sunny 25 3.40 5.8 Sunny 26 3.40 6.7 Sunny 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 3 7.5 4 7.8 Ice began mov ing 5 6.9 Ice flowing 6 1.00 6.1 Ice flowing 7 1. 20 7.8 Ice flowing 3 1 . 20 9 .2 Ice flowing 9 1 . 20 9.7 Ice flowing 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 1. Relative elevation based o n an arbitrary datum. 2. Average of the daily maximum and min i mum temperatures. 112 s5/cc2 TA BLE 5 .4 SUSITNA RIVER AT GO LD C REEK BREAKUP OBSERVATIONS ON THE MAINSTEM O pen Staff Mean Air Chan n el Gauge (1 ) Discharge (2) Temperature (3) Width (4) Date illl_ (cfs ) (oC) (ft) Weather April 1983 17 1700 2 .8 16 Snowi ng 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 20 00 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 31 00 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 .20 4200 7 .2 Open Rain 4 3 .33 4500 8 .6 Open Sunny 5 4900 7 .2 Open Sunny 6 4 .70 5400 Open Su n ny 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 o n an arbitrary datum. 2. Prov isio nal data subject to revision by t he U.S. Geological Survey , Water Resources Div is ion , Anc h orage , AK . 3. Average of the daily maximum and minimu m temperatu r es . 4 . Visual estimation based o n one daily observation . 113 "' -co ...... c ...... .. ~ CD en • .... Ei Cl)l ~ 0 • ~~~ ~ ~ ~~ -~ Q) Q) --z 0 i= < > w _, w w 0 6 0 < 10 u. a: ::;) U) a: 5 w .... < ~ w 0 > i= < _, w a: «! .- "' .- .! e .. • ~ WATER SURFACE PROFILES ALONG 1600 FEET OF RIVER BANK ADJACENT TO SLOUGH 21 BEFORE AND DURING ICE JAM ~ May 2 , 1883 vertical drop 3 .01 f eet In 1800 feat channel Ia lea c overed ICE JAM May 3, 1883 vertical drop 5.28 feet In 1600 feet channel Ia Jammed by Ice 300 eoo 800 1200 1600"': DISTANCE ALONG RIVER BANK (feet) C\1 "' .- .! e .. e ~ PHOTO 5.1 The confluence of Deadhorse Creek (at Curry) on April 28, 1983. Flow on the mainstern is from right to left. Open lead on the right is enlarg i ng a n d fragments of ice are accumulating against the solid ice cover at the downstream end. ---.... PHOTO 5.2 Overflow above the Parks High way Bridge o n April 7, 1983, covering the ice s heet wiH. ove r 6 inches of water. R&M CONSUL-TANTS, INC. eNOtNa•ae o•DLDOISTS •LANN .... S suav•Yo•s 115 SUS!TNA JOINT VENTURE PHOTO 5.3 This photo was taken on May 7 , 1976 from the Gold Creek Bridge, looking downstream toward Slough 11. The mainstem is completely ice choked and much flow has been diverted to the left into Slough 11. PHOTO 5.4 Looking upstream at edge of ice jam (river mile 77 . 6) o n May 3, 1983 , near Montana Creek confluence . Ice jam key was near river mile 76. R&M CONSULTANTS, INC. •NOINea•a 0.0\..00IBTa .\,.ANNa•• SU.V5 vo•a 116 SUSITNA JOINT VENTURE PHOTO 5.5 When this ice jam adjacent to Slough 21 consolidated on May 4 , 1983 it :reated a surge wave that snapped loose the shore ice and heaved blocks onto a gravel is land. T he view is looki ng upstream along the south bank. This ice is about 4 feet thick and the area affected by the surge extended several hund r ec feet. PHOTO 5.6 This is a close-u !J view of the ice bl ocks shoved ove r the r1 ve r bank at Slough 21 on May 5 , 1983 . Note the debr is scoured by the ice . R&M CONSULTANTS, INC . • NOINa••• D.OLOOI.Ta !laLANN••• au•va¥0.8 117 SUSITNA JOINT VENTURE PHOTO 5. 7 This shows the release of an ice jam key adj acent to Slough 11. This jam was about 0 . 7 miles lo ng on May 6 , 1983. The pressure exerted on the shore-fast ice by this accumulation snapped loose these massive ice sheets . PHOTO 5 .8 A triangular ice sheet wedged t ig :1 tl y betwee n two ~x tend e d s h e e ts of shore-fast ice o n May 6 , 1983 . This ice jam at Sherman lasted fo r 2 day!.. R &M CClNSr J LTANTS, INC. .NQINeeAB Oe'DL.OOIB'T. Pt...NN•A• •uAVCVO ... S 118 SUSITNA J OINT VENTURE PHOTO 5.9 An aerial view of the ice jam near Sher·ma n at ri ver mile 131 .5 o n 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 j am that lasted for 2 days. -- 7 PHOTO 5 .10 This is a close-up view of the ice sheet that wed g ed near Sherman. Massive blocks of ice had fr·agmented and fo rme d ridges along the sh ear surfaces . R&M CONSULTANTS, INC. •~to•,..•••• o•a~.oa:eaT• •t.ANNe•• a u•vcvo•• 119 SUS/TNA JOINT VENTURE . _, ~· . ,.a;_ .... ,. .... ' . --· .... -~ . .. ' ·. . -_,. .. .. ...... -l · . ' . . ., .... . . . .... ~ . -·-~--. -...... ·....,...--.. -_....,. -· . . . . ~.........._ '-. : .•.. ....... -, ' . . ·~. I. I PHOTO 5.11 . ..... __ ....... : . .· ....... , ' ·- The ice jam at Sherman accumulated over 1. 5 miles of debri s. The subsequent increases in stage and pressure wit hi n the ice pack shoved floes onto th e forested is lands . This ofte n knocked trees down and caused ice scouring . ... · .. -~-· ,-:--. . ~. 'y .-.~ ~­~-- This photo shows a grad ua lly progressing sl owly d isinteg rated . PHOTO 5.12 large ice jam at C urry on May 6 , 1983. This jam was downstream as t he solid ice cover holding back the debris R&M CONSULTANTS, INC. 120 SUSJTNA JOINT VENTURE aNOtNaa•• a•o-..oataTa ~~~»-..ANN•A • au•vavo•• .. .. . .. . . ·_ .. _._ PHOTO 5.13 Ice jam at Watana damsite, May 6, 1983. Flow is from right to left. Ice jam at upper right is near the entrance to the diversion tunnel . PHOTO 5 .14 The ice sheets hold ing bzck the ice jam at Sherman g•·adually decayed and weakened. They are shown here on May 8, buckled and fractured just before they released. Flow is f rom right to left. R&M CONSULTANTS, INC. eNO•N•••• ••o~oate.,.. ~H..._._. au•v•..,o•• 121 SUSITNA JOINT VENTURE -...._ ~ .... --... '!:1'--.. - ~-;-. ,....._:-.. PHOTO 5.15 Looking downstream from river mile 102 .5 at ice jam key ed at r iver mile 98.5 . This jam formed the evening of May 8, 1983, and extended to river mile 104. It released the evening of May 9 , 1983. 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-fores t . R&M CONSULTANTS, INC. •NOtN••"• o eo""ooteTa •\..ANN••• au•vevo•• 122 SUSITNA JOINT VENTURE PHOTO 5.17 Ice debris piled onto the ri v er at river 'mile 101.5. The approxn;--=-tely 14 feet high. The water level attained duri ng indicated b >' a line separating the dark layer , with a concentration , trtJ a lighter and thinner lay er on the surface . PHOTO 5.18 shear wall is the ice jam is high sediment View of the shear wall a long accumulated ice debris stranded o n the right bank near ri ve r mile 110. Fl ow is from right to left. This photograph was taken o n May 10 , 1983 abo ut 8 hours after the ice jam released . The wall is abo ut 16 feet high. R &M CONSULTANTS, INC. .NGtNaa•a OaOL0018T8 DLANNeAS •u i•VeYOaa 123 SUSITNA JOINT VENTURE s 16/u 1 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 , v elocity , 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 pf processes by which particles , both in suspension and saltation, can be moved. Ice nucleation, suspended sediment filtration , and entrainment of larger particles in anchor ic e are some of the processes described in this section. The dramatic nature of breakup often intro- duces 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 f lushes sediments from side chan nels and sloug hs . Ice blocks are heaved onto river banks or scraped against unconsolidated depos itional sediments, remov in g soils which may become entrained in the turbulent flow and carried downstream. Laboratory in vestigations have determined that ice readily nucleates around supercooled particles . These particles may be i n 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 wh ich may form the nucleus of frazil ice crystals. The first occurrence of frazil is genera lly also marked by a reduction in turbidity. Visual observations seem to i ndi cate that the decrease 1n turbidity is proportional to the increase in fraz il ice discharge. The Sus :tna has often been observed to clea r up ove rnight during heavy slush flows. It is not certain whether this occurs because of the nucleation process or by filtration . As described in prev ,:o us sections, frazi l ice crystals tend to flocculate into clusters and adhere together as well as to other o bjects . When frazil 124 s16/u 2 floccules agglomerate they form loosely packed slush (Newbury , 1978). Water 1s able to pass through this slush but suspended sedi ments are filtered o ut . Sediment particles are therefore entrained in the accumulat- ing ice pack. Ice shavings from bore holes drilled through the ice often contain s i lt-size particles of sediment. Early flows of slush ice accumulate on the lower river below Susitna Station and progressively advance up - st ream . These early slush floes possibly filter high sedi ment concen- trations in October and retain them in suspensio n all winter. When frazil ice collects on rocks lying on the channel bottom , it is re- ferred to as anchor ice (Michel , 1971). Anchor ice is usually a temporary feature, commonly forming at night when air temperatures are colde!.t , and releasing during the day. Like slush ice , anchor ice is porous and often has a dark brown color from high sediment concentrations (Photo 4 .9). These sediment particles were either o n c e suspended and subsequently filtered out of the water or else were tran sported by saltation until they adhered on contact with the frazil. When a nchor 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 s lu sh is therefore an effective medium for sediment transport dur i ng freeze-up whether the process is nucleation , filtration or entrapment . An ice cover advancing upstream can cause a local ofte n flooding previously dry side channels and r ise in water levels , sloughs. Substantial volumes of slush ice may accompany this flooding. On December 15, 1982, Sl o ughs 8 and 8A were fl ooded when the ice pack increased in thickness on t he mainstem immediately adjacent to the s lough entrance·. These sloughs received a disproportionate vo lume of slus h ice relat ive to water vo l ume since the water breaching the berm constituted only the v ery top layer of ma i nstem f low . The ma jo r ity o f slush ice floats near the water surface despite o nly minima l buoy a ncy. The flow sp i lling over the slo ugh berms therefore carried a high concentration of ice. This slush ice and 125 s16/u3 entrained sediment rapidly accumulat ed into an ice cove r that progresse1..1 up the enti r e length of Slough SA. Side channels and sloughs t h at were breac h e d d uring freeze-u p an d filled w ith slush ice are not necessarily flooded du r ing breakup. If these sloughs a r e not inundated then t h e ice cov er begi n s to det e r iorate in place. The entrained sediment consolidates i n a la yer on the ice surface and effectively reduces the albedo, furt he r increasing the me lt rate . What finally remains is a layer of fine sil ~ up to !-inch thick covering the channel bottom and shoreline. If berms are breached during breakup , then ice fragments from the mai n channel are washed i nto the slough and usual ly become stranded in t h e shal low reach (Photo 6 . 1). These ice floes then simply melt in situ, depositing thei r sediment load in the side channel. T his occurred in May 1983 when the "AS " access cha nnel to Slough 21 flooded during a major main stem ice jam , and also near Rabideux S lough (Photo 6 . 2). 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 p r ovide the critical lifting force to suddenly shift the borde r ice. This occurred near Slough 21 on May 4 , 1983 .• Tons of i.;e were shov ed onto a gravel island (Photos 5.5, 5.6), entraining partic les up to boulder-size and producing ridges of cobbles, gravels and organics. By th is process of laterally shoving substrata materia l , ice can build up or destroy considerable berms and change the size of grave l b ars near ice Jam locati o ns . When the lateral pressure exerted by ice is comp l icated by simultaneous downstream movement such as during an ice jam r elease , the effects on the r iver banks can be devastating . Many cubic feet of bank ma t eria l was scoured away in minutes when massive jams r e leased near S lo ugh 21 , Sherman , and Chase (Photo 6 .3) in May 1983 . An interesting phenomenon observed during breakup was the effective filtering capability of ice jams and individua l ice b locks. Sediment-l ade n 126 s 1 6/u4 water flows through the many channels and interstices between the frag- ments in an ice jam . These interstices are usua lly filled with porous slush wh ic h removes suspended sediments from the water . Ice jams can concen- trate sediment in this manner and often become very dark in color. As discussed, Susitna River ice generaHy consists of alternating la yers o f rigid, impermeable clea r ice and p orou s, loosely packed , rounded crystals of metamo rp ho sed frazil ice. Water can percolate throug h the permeable layers, which strain o ut suspended sediment particles. Th is 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. 127 PHOTO 6.1 Ice floes stranded by Slough 21 after the ice drive. --~ _"")-,. -~ ... . .. -~-: ~ PHOTO 6 .2 Silt deposit left at Rab i deu x Slough by melting block of ice. mechanical pencil in foreground for scale . Note th e ~&M CONSULTANTS, INC. .NQtN .I!DB OEOL00111T'8 •\.AN""'.AII S UDVeVORS 128 SUS/TNA JOINT VENTURE PHOTO 6 .3 After the ice jam released near Chase, the ice severely scoured the r iver :>anks and carried away large trees . R&M CONSULTANTS, INC. .NIGtN···· OaOt..OOieT • P~ANN.AS SUIIIVaYo•a 1 29 SUSITNA JOINT VENTURE s16/z1 7.0 Environme ntal Effects Ice processes have been a major en vi ron mental force on the Susitna River , affecting channel morphCllogy, vegetation , and aquatic and terrestrial habitats . The impacts vary along the length of the river . The en vi ron- mental impacts of ice processes will be summa r ized in the follow ing p,,ra- graphs. This will be followed by a brief discussion of potential mod if ica- tions to the ice processes of the Susitna River caused by operation of the proposed hydroelectric development, and the subsequent changes in en- vironmental processes . Ice processes appear to be e major factor controll i ng morphology of the r iver between the Chulitna r:.onfluence and Portage Creek . Areas with frequent jams have numerous side-channels and sloughs. T h e size and configuration o f existing sloughs a p pear t o be dependent on the frequency of ice jamming in the adjacent main s tem . Major ice events probably f o r med the sloughs when ice floes surmounted the river banks . The size an d configuration of existing sloughs is depen - dent on the frequenc y of ice jamming in the adjacent mainstem . Ice floes can easily mo ve the bed material , substantially modifying the elevation of entrance berms to the sl o ughs. In May , 1983 , a surge wave overtopped a sha l low gravel bar that isolated a side channel near Gold Creek. The surge also created enough lift i ng force to shift large ice floes. These floes barely floated but were carried into the side channel by the onrush o f water , dragging against the bottom for several hundred feet , scouring troughs in the bed material . T his same process will also enlarge the sloughs . When staging is extreme in the mainstern and a large vo lume of water spills over the berms , then ice floes drift into the side channel. These ice floes scour the banks and mo v e bed mater ial , expanding the slough perimeter . T h is scouring action by ice c a n the r efore drastically alter the aquatic hab itat. 130 s16/z2 The erosive force of ice effects vegetation along the river. The frequency of major ice jam events is often indicated by the age or condition of vege- tation on the upstream end of islands in the mainstem. Islands that are annually subjected to large jams usually show a stand of ice-scarred ma- ture 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 origi.nal vegetation. Vegetation is prevented from re-establishing by ice jams that comp letely override these islands. Ice processes have several impacts on aquatic habitat . The sloughs may fill w ith slush ice, which then forms a ice cover up to 5 -6 feet thick. This would prolong colder than normal water temperatures in the slough. (It could also cause problems for any beavers with lodges in the s lough by filling pools with ice). Diversion of flow and ice into the sloughs may cause large changes in channel morphology. Large amounts of silt may be deposited in the system at breakup , migrating dow t1s ream during hig h flows in the summer and covering good spawning habitat . Ice processes do not appea r to play as important a role in the morphology of the Susitna River below the Chulitna confluence . This river reach below the confluence regularly experiences extensive flooding during summer storms. These seem to have significantly more effect on the riverine environment than processes associated with ice cover formation (R&M, 1982a, 1982c). This reach is characterized by a broad , multichan- nel configuration with dist ances 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 the thalweg is bordered by a1'l expanse of sand and gravel (R&M, 1982c). Although ice cover progression fre- quently increases the stage abo ut 2 -4 feet above normal October water levels, no significant overbank flooding takes place, although some sloughs and the mouths of some tributaries do receive s o me overflow. The ice 131 sl6/z3 cover below Talkeetna is usually confined to the thalweg , and surface profiles rarely approach the vegetation trim line along the banks. Operation of the Watana and Devil Canyon projects would significantly modify the ice regime of the river below Devil Canyon . Flow rates will be 2 -4 times greater than natural winter flow rates, with water temperatures of 2°-4°C immediately below the dams . The frazil ice generated i n the upper basin i n early winter will be trapped by the upper reservoir . Once Devi I Canyon Dam is built, the major rapids in the system will be flooded, further red ucing frazil ice generation. These major changes in the phys- ical system and in the hydrologic and thermal r egimes will combine to greatly delay ice for·mation below the project . Progression of the ice cover on the lower Sus 1tna is now due to rapid juxtaposition of ice floes from the upper nver , with the Sus itna River contributing 70-80 percent of the ice . Much of this ice will not be avail- able under post-project con ditions . Ice cover progression initiates when an ice bridge forms at about R M 9 at a sharp bend in the river. With the reduced volume of ice available under post-project conditions , formation of this bridge will be significantly delayed , or may not even form at all in some years . Consequently , ice cover on the lower Susitna will form at a later date than now occurs . Progression of ice up the river will also be much slower , due to the reduced ice discharge from the upper Susitna. Water temperature below the project will not decay to the freezing level for man y miles . It is more likely that an ice cover will form on the river above the Chulitna confluence when on ly the Watana project 1s opera ting , than when Devil Canyon is also on line. The ice cov er now progresses upstream from the Chulitna confluence when slush ice bridges a narrow channel at the confluence . One question now under study is the formation process of this bridge. In some years , this bridge does not appear to form until ice cov er has progres !.ed up the low er Susitna River to a point near the conf luence . However , it has also been observed to form indepen- dently when heavy ice discharges were unable to pass through the 132 s16/z4 channel, and when the lower Susitna ice cover was still far downstream . Formation of the bridge appears dependent on the rate of ice discharge from the Susitna above th is point , and o n the location and flows o f the various Chulitna River channels . It must still be determ i ned if sufficient ice will be generated under post-project conditions to cause this bridge to form and whether an ice cover will progress up the lower ri v er in time to help form this bridge. If ice does progress upstream of the Chulitna confluence, staging levels will probably be higher, as flow level s and v elocities will be greater than under natu rat cond itions . Breakup patterns will change on the river below the projec t . An ice cover may o r may n o t exist above the Chul itna confluence . The warm water released from the reservoirs, combined with the i ncr~ased air temperatures and solar radiation in s pring , w i ll cause the upstream end of the mainstem ice cover to decay earlier in the season. Flow levels will be significantly lower in May as the reservo ir stores flo w from u pstream . No ice will reach the river above the Chulitna confluence from above the reservoirs . The breakup processes now occurring above the Chulitn a confl uence will be effectively elim i nated. Below the Chul itna confluence , breakup impacts w ill probably also be reduced due to the lower breakup flows , although ice thicknesses may be increased due to the increased winter flow levels . The lower Susitna Rive r generally is ice-free before the final breakup dr ive reaches it from above the Chulitna c onfl uence . 133 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 . Vo l. 10 . pp. 369 -392 . Benson, Carl S . 1973. A Study of the Freezing Cycle in an Ala skan Stream . Fa i rbanks , 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 Meas urements of River Ice Jams. Water Resources Research , Vol. 14 , No . 4 (August). pp . 693-695 . . 1979 . Acce lerated 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 U niversity . 124 pp. Michel, Bernard. 1971. Winter Regime of Rivers and Lakes. U.S. Army Corps of Eng i neers, Cold Regions Research a!ld Engineering Laboratory , Hanover, New Hampshire. 130 pp . Newbury , Robert W. 1968 . The Nelson River: A Study of Subarctic River Proc.esses. University Mi c rofilms, Inc ., Ann Arbor, Michigan. 319 pp . 134 s16/y2 Osterkamp , Tom E . 1978. Frazil Ice Formation : A Review . Journal of the Hydraulics Division . Proceedings of the American Society of Civil Engi neers . September , pp . 1239-1255 . R&M Consultants , Inc. 1981a . Hydrographic Surveys Closeout Report . Anchorage, Ala ska . Alaska Power Authority . Susit na Hydroelectric Project . Report for Acres American, Inc . 1 vol. 1981 b . Ice Observations 1980-1981 , Anchorage, Alaska. Alaska Power Autho rity . Susitna Hydroelectric Project . Report for Acres Ameri can, Inc . 1 vol. 1981c . Preliminary Channel Geometry, Velocity and Water Level Data for the Susitna River at Devil Canyon. Anchorage, Alaska. Alaska Power Authori ty 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. 19 82b . Hydraulic and Ice Studies . Anchorage , Alaska . Alaska Power Authority . Susitna Hydroelectric Project. Report for Acres American, Inc . 1 vol. 1982c . Hydrographic Surveys Report. Anchorage, Alask.L Alaska Power Au+:hority. Susitna Hydroelectric Pr·oject. Report for Acres American, Inc. 1 vol. 1982d. Ice Observations 1981-82. Anchorage , Alaska . Alaska Power Authority . Susit na Hydroelectric Project . Report for Acres American, Inc. 1 vol . 135 s16/y3 1982e. Processed September 1982. Anchorage, Susitna Hydroelectric Project . 8 vol . Climatic Alaska. Data, October 1981 to Alaska Power Authority. Report for Acres American , Inc. 1982f. River Morphology. Anchorage, Alaska. Alaska Power Authority. Susitna Hydroelectric Project. Report for Acres American , Inc. 1 vol. 1982g. Sloug h 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. Wate r Resources Research , Vol. 15 , No .2 (Ap ril). pp . 469-475. U .S. Geological Survey . 1982. Water Resou rces Data , Alaska, Water Year 1981 . Anchorage , Alaska. Water Resources Division, U .S. Geological Survey. United States Department of the Interior . 136 s 16/y 4 APPENDIX A Month ly Meteo rological Summaries for Weather Stations at Denali, Watana, Devi l Canyon , Sherman and Talkeetna 137 C D N ~;3 U!... T ~.NT E > H Y D I~ DE!... E C T I ~ :1: C MON THLY SUMMARY FOR DENALI WE~THER ST~TIO N DAT~ TAKEN DURING Dece Mber > 1982 !lAX. TE!iP . ~EC C ( KIN. TtHP. DEC C MEAN ID!P. DEC C RES. WI!!D JHR. DEC RES . umo SPD. 11/S AVC. IHllD SP!'. 11/S llfiX. GUST DIR . DEC ~AX . GUST pI 1JAL !lE t,~ SPD. DIR . RH 11/S % :t:NC. MEAN DP DEG C PRECIP M ~ ~AY'S SOtAP. ENERC~ DAY WH/SQ~ -------------::-:i:"'l------------------------------------------------------ 1!1!11!1 Hfl!l l!lfH Ul 1!1!!1 !HI HI IU!! U!l U H!ll!! U U lf'UH 2 filii Hll!l tilt\ . !H HI! f!fl !I! Iff! HI !!! !HI!! HI!! H!!!!l!! 2 J -27 .2 -35 .4 -31.3 Uf fHI Ulf U l H!!l Uf !I H!fl :tllll 462 3 4 -24.3 -32.0 -28 .2 1!1 11!!1 !!!I !!I!! 11!!1 !I!! I!! 1!!1!1 !!!!I! ~60 ~ 5 -15 .4 -2e.1 -21.8 Ul lUI 1!111 !!H !!Uf !!1!1 I!!! Hll!ll Ulll 315 '5 6 -4.4 -21.9 -13.2 If!! HH H!!l !II Hll HI! !l! !!X !!I!! 1!!1!! 37 ~ 6 7 2.7 -7 .7 -2 .5 l'U liH!! Ulll! HI !!!1!!1 I!U H HIH Hit 312 7 8 .6 -5.0 -2.2 Ill! 11!!11 !!!!I !II !Ill II! *!! !!1!!1! Jl!!! 33~ S 9 -1 .0 -20 .7 -10.9 !!!! 111!1 11!111 Ill 11!1!! 11!!1 1!1 l ·lfl!! *!!t \28 9 10 -18 .o -27 .4 -23.0 !1!!1 Jl!lf 11!1 !!I!! UU U!! I!! Hll!l Wll 379 10 11 -9.8 -25 .9 -17 .3 Iff 1111! 1!!11 !I! 1111 1!!1 II 1111!! 1111 265 11 12 -7 .6 -!2.6 -10.1 ~!1!1 1!!1! 111!1 I ll !!1!!1 !!II I I 11!!1! 1!111 355 :2 13 -3 .4 -!0.9 -7 .2 !Ill f l fl !!1!!1 Ill !Ill ~II !I lf.fl!! ll!!ll 308 13 14 -5.5 -16.8 -11.2 II! Iff!! lllf 1!!!1 !11!1 !I! I!! 1!!1!1 !~I!! 303 1~ 15 -5 .2 -16.3 -10 .2 Ill Ulf U ll 1111 HI!! Ul !!!! II!H Ull 318 15 16 -12.9 -17.7 -15 .3 W!l !~II 1!1!1 1!1 ~~~~ !f!! ~~ ~!II! 1~!!1 299 !~ 17 -7 .8 -15 .3 -11.6 !1!1 ~~~~ 1~11! !!II fl!!l !!I! t f. ~1!!11 *Ill 24t 17 18 UUI IU!I!I !tit! fU !IU UH !1!1 UH U'! H !!!!!!!'! l!!~f ~I U!I !9 1~ H ilt 1!!1!!1 ui;~ U!! U!!l ~.:H IH lUI !IH ll!l H fl!! I~H I!!Hit 19 20 llfll 111!1 !!II~, tl!! llll '!f\1 til lll!l 1!!1 ~~ lfl!!l ~!!!!! X~l~l!! 2 ~ 21 l llfl Ifill ~~-~ HI !I!H H!l!! U!l !H!! f!!l I!! HHI flU ·l!f-Hfl 2! 22 IIIII !11!1 ~~ Ill 11!1 11!!1 !!I! ~~~~ 1!!1 ~~ ~1!11! ~!!I! ll!!l!!!! 22 23 f.l!lf !l!lfl ~ltif Ill ~!Ill ~Ill !I!! flf.l !!!I !!J !!1!!!1 ~1*1 fi*F~l 23 . -.; 24 !lltfl IIIII II!~ !II !1!!1!! 11!1 1!!1 !!1!!1 !I!! I!! !!1!!!!1 II!~ Jl!!!!l!! 2~ 25 26 27 28 29 30 31 MONTH l!UH H ill I!UU l!l!ll UUl! J!F'IIf 9JiH 2.7 !!l!l!f!! HI I! lllllf lilt! H!'tf HUll -35.4 UfH l~ . ·.' fllfl . I ~ lflH ... : .o HUI -to,. !HH itlu -14.4 HI Ill!! 11!!1 Ufl 1111 IIU 1!!1!! :t!!ll !!!I!! I GUST VEL. AT M~X. GUST VEL. ~T MAX. GUST VEL . AT MAX. GUST VEL. AT MAX. l!!l!! IHI uu !19!1 ~~!!,; HI!! li!!H HH GUS T MINUS GUST MINUS GUS T PLUS GUST PLUS lUI IU t !!U Ul !!II! IU l~U Ul ~.n'! a!! l!!H HI 1!!11 !!U li!!~!l l!lf!!l !!I!! I! HI!* XH!II Ul!!!f U!!l!! Ul!! Ulf ll!!l !U~J 2 IN TERV ~LS ??9 .0 HITER'.1 AL 9?9. C 1 INTERVnL 999.0 2 INTERVnLS 999.0 UHH 2~ :'!li!!~H 26 !lll!!ltt 27 !lll!f!! 28 H ·~~H 29 ~P:~l:!' 3Q *!X·!H 31 5 l~~ NOT~: RE L~TIVE HUMIDITY RE~DINGS ~RE UNRELinBLE WHE N WIND SPE~DS ~RE LE33 T H~N ONE METER PER S ECOND. SUCH REnDINCS H~V E NOT BEE~! INCLUDED IN THE J AIL~ 0!~ MOtHHL Y ME~N FOR RELt'ITIVE HUMIDITY r~ND DEW POH!T. x .. :o: x GEE t!OTES IH THE BACI < OF THIS REPORT X··Y.··X··~ 138 J I ; ·t ·-. ..-D t< U :;:: i ... ,;;: C T I ~ :t: C MON II-tt. t . SU MM 14" t FCR D1~N i-lt. I \IJ E1-H ··1E1~ S i A f IQrJ DA TA TAI(EN DL ~IN G january .. 1983 DAY MX. iEr.?. w; ~ rl itt . itn?. Dt:; C KES. WIND DIR . DtG .<t:S . ~tlrlD Si'D. :liS A'~G . lHND SPD . i\/S MAX . CUSi DIK. D:.G MAX. GUSi ? 'VAl nEAN SrD. DiR . RH ;;;s z :1: h!C . hi: AN DP PK EC:P DEG C nri ~A I 'S SO LAK chERG'f DAY wn/SQn ----------------~------------------------------------------------------- 1 2 3 4 5 6 i B 9 10 \1 12 13 14 15 16 17 18 1Y 20 21 22 23 24 25 26 27 28 2'? 30 31 .::::: ::::: ~~~ ::: a!t ttt ttlfl I**** Ill -:1 ... - ktSU fllilt ~; *** UOt UOt ••• ,~ HI fUU UtH *_*!!.' IH UtU Hltt ItO~ Hf UHI UIU i~ HI .. "f •·- UUI lltUt t_t~t~ . hi jfttf IIIII it~ Itt Ulltt UUII -25 .9 -32 .8 -26.3 -36 .6 -L7.o -32.'1 -14.7 -24.4 -8.3 -\8.2 -7.6 -H.B -5.8 -14.4 -6 .7 -13.6 -il.2 -19.1 -i2.6 -23 .3 -17.3 -24.7 -16.5 -2 7.5 -8.6 -2o .u -13.5 -24 .~ -9 .5 -2\.o -e.3 -1Y.4 -5.8 -14.2 -:2 .8 -~2.6 -a.o -23 .1 -o.5 -i ~.o tUU Uf -29.4 -32.2 -25.3 -19.6 -13.3 -11.2 -10.1 -10.2 -13.7 -18.0 -21.G -22.6 -14.3 -19.0 -15.6 -13.9 -LO .D -17 .il -15 .& -10.1 fU IH nt .... Uf 1 1111 *** Ut tit Ul HI ~u Iff !Ht Uf tltt HI Hit *** Ut .Hiillt .tttt ..... Hit Utt **** uu uu **** Utt .... uu lUI lith .... uu 11*1 Ulltt nu uu Hit UH II HI HU Off UH HH r.i:Jt1i H -5.2 -36 .\i -!7 .I u~ GUST ~E L. AI MAX . GuST VE L. AT nA ~. GUST ~EL . AT nA~. GJ~T VEL. AI nA~. HU UH lUI 111ft **** nu H it tllil Uti Uti Hill .. H lUI Ulll Uti HH IIU UH on uu O ff UH on HU .... uu -uu uti tU fill Ul HI Ull i ll Ill HI ... *** Itt Ut ... HI Ul Uf HI lH HI k)t Ill IU til ... IU fU "** ktft Uti Ill Uti *** kUII Ut till "ltl Hftl Ill lt•** Ut 1111 ... 1111 Ul uu fit till Ull uu Ifill 1111 Ul 11'.1 Ut fH Ill Uti fit IU IIU HI Rtll IIH Hll HI uu t i U Ul HI nu N t 1111 Ill lUI Uf HU Ill Ull Ill **** HI nn xu UU fH Ut II ** 77 75 ao n u .. H u .. lit ** 83 59 71 83 u II If H tt tun ..... II HI fUll ltfHt -32 .4 -35.1 -32 .5 IIUit filii HtU UHI IUU UIH HUt tllllt -2 ~.4 -2 1.9 -24.7 -1&.9 IUU ..... UHI ..... Hit uu lUll flit *"* ttl II lll* .... nn flit .... IIIII Uti tiff nu lUI HH ••u **** *"* lilt Ull It If HH fl~l ·~~ 74 -26 .9 ~·~· GuS T MINUS c INT ERVALS 999.0 GuST MINUS 1 INTERvAL ~99.0 GUST PLuS 1 I~TE~V AL 999.0 GUST PLUS 2 INTERVHLS 999.u UIHI 1 2 4 6 7 a ~~..... 10 Utili 11 12 UIHI 15 unu l b Ulttff 17 18 19 ...... ~0 UUtt ~~ Hlttf 24 HHtt 25 2il 27 28 IIHH ~:UfH 29 1-H fft 3 ~ UJ:Ut 3. HU..t~ Nuf E: ~ELATI~E ~JM I~IIY REhDINGS ARE UNRELIABLE WH EN WIND SPEEDS H~E LESS ~hAN O~E nETER ?ER S ECON D . 3WC H READ I~GS HAVE NOT BEEN INCL J DED IN TH E DAiLf uR M8N Tn L f MEAN F O~ RELAfi~E riUMIDITY AND DEW POiNT . ~~•• S EE ~DT E~ AI ~rlE BAC~ OF Trl iS REPORT k**~ 139 &. M CONSULTANTS > :t:Nc . MON THL Y SU MMAR Y FOR DENALI W£ATHER STATION DATA TAKEN DURING February 1 1983 RES . RES. 1\VG, MX. MX. DAY'S MX. tUM. lOt IIlii) III MD IIIND QJST GUST pI VIi. I£AM II£Ajt SOLAR DAY rot . IDI. mtP. III. SPI. SPO. DIR . SilD. DIR . RH DP PIECIP ~DAY GC DE~ C IG C DE~ IVS 11/S DEG IVS I DE~ C lilt IIVSQI\ 1 .7 -14 .2 -6.8 IH tHI IIH tH ltHI tH H HHt tHI HHH 1 2 -4.2 -11 .8 -8 .1 IH tHI ffH IH HH ... H ..... HH IHfH 2 3 -3.7 -tt. I -7.4 IH HH IIH IH IIH IH II HIH HII 241 3 4 -4.6 -11 .9 -8.3 HI .... ifH HI HH IH H IHH IHI 698 4 5 -4 .4 -14 .2 -9.3 IH tHI IIH Ill IIH IH H HHI Hit 813 5 6 -3.6 -11.6 -7.6 IH .... tfH ttl IIH tH II tHH HH 743 0 7 -3 .2 -B . 1 -S .7 Ill HH HH IH IIH Itt H ttHI IHI 851 7 8 -5.3 -9.9 -7.6 IH IIH IHI ... IHI IH H IHH IIH 578 8 9 -9 .2 -t4 .i -11.6 IH HH IIH Ill HH Ill II HIH IHI ne 9 11 -l\.9 -22 .4 -17.2 ... HH IIH IH IIH IH .. tHfl HH 873 11 1t -13 .7 -24 .9 -19.3 IH HH IIH IH IIH IH II ..... HH 1378 11 12 -15.7 -26.8 -21.3 IH tiH .ffH IH tiH IH It tHH IIH 948 12 l3 -22 .8 -31.8 -2&.4 IH IHI HH HI HH IH H IIIII "" 1S5S 13 14 -19 .2 -3t.o -2S.4 IH I H* HH IH tiH IH H Hilt IHt 17SB 14 15 -111 .7 -31.2 -24 .1 IH IHI HH IH IIH IH H ..... 1111 tns IS 1& -1 7.5 ·31.4 -24.5 IH *"' .... *" 1111 ... .. tHH Htl 1845 16 17 -11 .o -31.4 -24.5 Ill .... HH IH IHI IH .. IHH tHI \895 17 19 -14 .5 -31.0 -22 .8 HI IHt IIH IH HH IH II ..... IHt 1221 18 19 -4 .9 -19 .1 -12 .1 IH .... HH HI ltHI IH H II HI HII 1995 19 28 -8.3 -19.1 -13.7 HI HH IHI IH IIH IH H IHH HH 1663 21 21 -s.s -18.6 -12 .1 IH .... UH IH HH Ill H IHH IIH 1988 21 22 -5 .o -18 .1 -tt .o IH iHI I IH tH IIH IH H HHI IHt 2138 22 23 -8 3 -22.1 -1s.s HI HH HH HI HH IH :'"1 HHI IHI tern 23 24 -3.3 -12.5 -7.9 IH tiH IHI IH HH IH H tHH HH 1298 24 25 -8.3 -17 .6 -13.1 HI ltH IIH tH Hit IH H ..... .... 2881 25 26 -b.b -15.8 -11.2 HI HU IHI ... ltH IH ** HIH IIH 2170 26 27 -8.4 -17.2 -12.8 ... IHI .... . .. HH IH H HIH tHI 18b3 27 28 -3.8 -11.4 -7 .6 ... 1.8 ••• ltH ••• HI fl tHH IHI 1319 28 ltOMTH .7 -31 .6 -14.1 IH 8.1 1.8 tH 8.1 IH H litH Hit 30483 GU S T VEL . AT MA X. GUST MINUS 2 INTERVALS 999.0 GUST VEL. AT MA X. GUST MINUS 1 INTERVAL 999 .0 GU S T VEL . AT MA X. GUST PLUS 1 INTERVAL 999.0 GUS T VEL. AT MAX . GUST PLUS 2 INTERVALS 999 .0 NOT E : RE LA TIVE HUMID I TY REA DINGS ARE UNRELIABL E WHEN Wl i'J D SPEEDS ARE LESS THAN ONE METER PER SECOND . SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHL Y MEAN FOR RELATIVE HUMI DITY AND DEW POINT. 'JBt·lt·lt SEE NOTES AT THE BACK OF THIS REPORT «-*·)(-·)to 140 I~ J.')c M C D N ~:> U 1... T ANT ~:; ,. :I:NC • b u ~:~ .1. rNA H Y D l~ DEl... EC T I~ :t: C P I~D,T ECT • MONTHLY SUMMARY FOR DENALI WEATHER STATIO N DATA TAKEN DURING Mar ch , 1983 I RES . RES. AVG. 111\X , 111\X , DAY 'S MX . IUN. ItEM WIHD IHHD WIND GUST GUST P '~-IIEAH fi£AN SOLAR i DAY TEN . rntP . rot. Dill. SPD . SPD. DIR . SPD. DIR . ~H DP PRECIP EJOGY DAY DEGC DEG C IG C DEC IVS IVS DEC IVS I DEC C "" WK/SQit 1 -7.7 -18.4 -13.1 HI HH HH IH HH IH H IHII IHI 1321 1 • 2 -11 .5 -23 .2 -17.4 IH HH IIH tH 1111 IH II I Hit IHI 1515 2 3 -12.& -26.2 -19 .4 HI "" ltH tH IIH IH H Hill IHI 983 3 ~ -12.5 -19.7 -16.1 Ill HH HH tH .... tH H IIIII HH 1313 4 s -18.1 -20.0 -15.1 IH HH IIH tH 1111 IH H HtH IHI 1178 s Q -18 .1 -20.6 -15.4 IH HH HH ... IHI IH H ..... UH 1865 b 7 -9.4 -21 .9 -15.2 IH HH IHI tH HU tH H tHII "** 2158 7 8 -11.7 -2&.4 -19 .1 Ill lilt IHI Ill Hll HI II IIHI HU 2333 8 I 9 -18.7 -2b.7 -18.7 tH 1111 Hll tH HH tH II Hill IHI 3129 9 11 -8 .8 -14.3 -11.& 348 1.5 1.7 257 7.8 NHW II IHH IHI 2885 10 11 -1.7 -13.4 -7.& 174 2.4 3.3 106 8.9 SSE .. IIHI IHI 2713 11 ' 12 1.8 -12 .5 -5.4 12& .1 l.b 1bS 9.5 MMW II IHII tiff 2318 12 13 -.8 -1o.2 -8 .5 338 .7 1.2 333 3.8 MNil H Hill IHI 3193 13 1~ -4 .2 -17.1 -11.7 33& .4 .9 3~ 3.2 NHU If HtH HH 2890 14 15 -.9 -15.0 -8.1 172 .5 1.7 1&5 5.7 s H Hffl IHI 2573 15 I ta -:u -to.& -o .a 347 1.8 2.8 l4e 5.7 NNW If IIIII IHI 3133 ta 17 -5.1 -1&.0 -11.& 348 1.1 1.4 330 3.8 MMII H Hill IHI 30 ~8 17 18 -4 .9 -21 .& -13 .3 342 .8 1.3 350 3.8 NHW .. IIHI IHI 3330 18 19 -&.4 -19 .7 -13.1 335 .b 1.0 330 3.8 NNW H Hill IHI 3388 19 21 -3.4 -1&.4 -9.9 244 .1 l.S 1&8 7.& N II Hill IIH 3285 20 21 -.9 -15 .1 -8 .0 341 .7 1.1 180 3.8 M II lUff IHI 3578 21 22 -3 .3 -1b.b -10.8 344 .b 1.0 &Ub 2.5 NHW H HHI IIH 3703 22 23 -4.7 -18.0 -11.4 341 .8 1.0 335 3.2 NNW H IIIII IHI 3855 23 24 -3.9 -19.8 -11.9 343 .7 u 004 3.2 NHW 'I IIIII '"' 3178 24 25 .1 -14.3 -7.1 340 .9 1.3 358 4.4 NMII .. IHII IHI 3923 25 26 -3 .7 -17 .0 -18 .4 170 2.2 3.0 17& 10.8 s II ..... IIH 3808 2& 27 -3 .& -15 .9 -9.8 175 l.b 3.2 172 12.7 s If Hill Hit 3933 27 28 -&.3 -17.8 -12.1 348 1.3 1.7 127 5.7 IIHW .. IIIII IHI 3888 28 29 -l.b -28 .0 -18 .8 341 .B 1.3 344 3.8 NNW H IHH .... 4258 29 30 -2.1 -1 7.8 -10.0 345 .7 1.1 348 3.2 NM\1 II II HI HH 4333 30 31 -1.8 -1&.9 -9 .4 348 l.b 1.8 218 5.1 NNII II HIH IHI 3870 31 liOIITH 1.8 -2&.7 -ll.B 335 .4 l.b 172 12.7 HNII II Ifill l fll 90588 GUST VEL. AT MAX. GUST MINUS 2 INTERVAL S 9 .5 GUST VEL. AT MA X. GU ST MINUS 1 INT ERVAL 9 .5 GUST VEL . AT MA X. GUST PL US 1 INTERVAL 11 . 4 GUST VEL . AT MAX. GUST PLU S 2 INTERVAL S 1 1 . 4 f NOTE: RELATI VE HUM IDITY REA DINGS ARE UNRELI ABLE WHEN WIND S PEED S ARE LE SS THAN ONE ME TER PER SEC OND . SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTHL Y MEAN F OR RELATIVE HUMIDITY AND DEW POINT. SEE NOTES AT THE BACK OF THIS REP LlR T ·)(-·)(-·X. ·X· 141 l~ & M C DNSUL.T~•NTS _, :J:NC. MON THLY SUMMARY FO R DEN ALI WEATHER STA TI ON DATA TAKEN DURING Apr i 1 .. 1983 RES . RES . AVG . MAX . th\X . DAY'S MX. IHN. ltEAH WIND WIND WIND GUST GUST pI Vtt. tiEAH !lEAN SOLAR DAY TEttP. TElf. TEMP . Dll. SPD . SPD. DIR. SPD . DIR . RH DP PRECIP ElERCY DAY DEG C DEG C DEG C DEC tVS lt/S DEG lt/S I DEC C "" WtVSOfl 1 -1.1 -16.8 -9 .0 348 1.6 1.9 342 5.7 NtiV h *"** 8.1 4385 1 2 -.7 -1&.5 -8.6 339 1.2 t.b 3~ s. 1 MNW ** IIIII 1.0 4b83 2 3 3 .8 -14 .5 -5 .4 lSI 2.9 3.8 138 23 .5 s H HHI 0.0 4735 3 4 4.5 -4.4 .I 195 2.1 •. 1 154 20.3 IISW ** HHf 8.8 2448 4 s .8 -8 .8 -4 .1 166 4.1 4.5 152 13.3 SSE .. II HI 0. 0 4065 5 & 1.3 -10 .9 -4.8 186 .4 1.6 184 7.0 s ** IIIII 0.1 5048 6 7 .8 -13 .9 -6.6 335 .8 1.4 Ott 5.1 lltN II HHI 0.0 4655 7 8 .8 -16 .9 -8.1 341 1.6 1.5 34b 3.8 HNW .. IHII 0.8 4871 8 9 2.7 -11.7 -4 .5 339 .6 1.4 225 s. 1 NtN H UHf 1.0 4615 9 10 -6 .7 -18.6 -12.7 001 3.4 3 .5 006 6.3 H II ***** 8.8 5410 10 11 -4 .2 -22 .2 -13.2 188 1.5 3.2 141 1&.5 sw II I HII 0.0 3783 11 12 4.3 -5.0 -.4 168 3.1 3.8 140 15.2 SSE If *'*** o.a 4235 12 13 -.b -9 .9 -5.3 344 1.3 1.8 335 5.1 Htftl u ...... 9. 0 :i398 13 14 1.9 -2.9 -.5 191 4.1 5.8 177 12.7 s II IIIH ., ... 5098 14 15 2.1 -3 .0 -,5 161 3.9 4.3 155 12 .7 SS£ II HHI .2 4031 15 1b . 1 -4 .2 -2. t 351 4. 0 3.1 339 7.6 MHW H ..... 0.0 5368 16 17 4.b -8 .2 -1.8 241 .2 2.b 161 11.4 NttE II ..... 8.0 5551 17 18 2.4 -4.1 -.9 152 4.8 5.4 137 17 .8 SSE .. ***** 0.1 56Z8 18 19 3.1 -2 .2 .5 152 b.O 6.5 144 20 .3 SE H II HI 0. 0 5908 19 20 5 .7 -4 .1 .8 176 2.2 3.0 162 14 .0 s .. ..... 0.8 5815 20 21 4.2 -5 . D -.1 181 .9 l.b 159 7.6 s H IIIII 0.0 6893 21 22 5.8 -4.2 .4 181 3.3 3.5 lb7 11 .8 s .. *"** 0.1 6340 22 23 5.4 -1.8 1.8 191 1.7 2.0 ISS 7.6 s H ..... I. i 5171 23 24 5.7 -2 .4 1.7 340 2.1 2.5 339 8.9 NMW .. ..... 1 .0 6921 24 25 12 .5 -2 .5 5.0 329 .7 1.7 lbb 5.7 It H tUff 0.0 6805 25 26 6.4 -3.5 1.5 348 2.8 2.9 006 b.3 liN .. . ..... 0.0 &m 26 27 6.5 -3.3 1.6 359 2.7 2.8 019 5 .7 N •• ..... 1.0 6865 27 28 7.8 -4.7 t.b 326 .6 1.2 330 4.4 NHW .. ..... 0.0 sass 28 29 5.4 .2 2.9 359 2.2 2.3 351 6.3 H H t~HI .4 '\ItS 29 JO 4.4 -2.8 .8 3S3 3.8 3.9 339 8.9 N .. Hill 8.0 7128 30 ~n• 12 .5 -22.2 -2.3 166 .4 2.9 138 23.5 NNW .. ..... .8 154391 GU3 T VEL. AT MA X. GUST MINU S 2 INTERVALS 20.3 GUST VEL. AT MA X. GUST MINUS 1 INTERVAL 19.7 GUS T VEL. AT M~X. GUS T PLUS 1 INTERVAL 19 .7 GUS T VEL. AT MAX. GUS T PLUS 2 INTERVAL S 17 . 1 NOTE: RE LA TIVE HUMIDITY REAl>INGS ARE UNRE LIA BLE WHE N WI ND S PEEDS ARE LES S THAN ONE METER PER S ECOND . SUCH READINGS HAVE NOT BEEN INCL UDED IN THE DAILY OR MON TH LY MEAN FOR RELATIVE HU MIDIT Y AtlD DEW POIN T. l(-·X·'.<-·~ S EE 'NOTES AT THE BACK OF THIS REPOR T -)(--~~·')(> 1 42 1 -~ ·-o. :t: i'-J c . SUD T T NA H Y :0 1~ OF L EC ·r F~ T C P t:.c• 0 .. T E C T MON THLY S UMMARY FO R DFN ALI WFATHER STATION DA TA TAKE N DURING M~v . 1983 DAY ltAX. TEMP. DEG C 111~l . TEMP . DEG C b. I -5 .2 5.0 -.8 3 ***** 4 3.8 5 5.5 6 b.S 7 6.8 8 8.8 9 9.8 10 9 .2 11 10.2 12 7.4 13 I 1.3 14 9 .9 15 13 .7 tb e. 4 17 5.9 18 5. 7 19 °. 0 20 11.1 21 8. 5 22 8.7 23 8.5 24 9.6 25 13 .1 26 7.7 27 9.6 2R 13.9 29 16.1 30 21.4 31 15.0 MO NTH 21.4 Hllll -4 .5 -3 .0 -2 .4 -1.3 -I. 7 -2.8 -1.6 -2.5 1.0 2.5 1.8 1.0 ,4 1.2 -l.b 3.3 1.8 'l ') ....... .6 1.1 .1 2.4 0.0 3.4 5.0 7.7 ~.3 -5 .2 liE AN TEMP . OEG C RES. \liND DIR , DEG .5 206 2.1 218 Hill liH -.4 229 1.3 334 2.1 no !.8 348 3.6 346 3.5 229 3.8 203 3.9 312 3.9 2Q3 6.2 195 6.2 198 6.3 324 4, 7 192 3.2 2!Q 3.5 170 3. 7 321 7.2 283 5.2 263 5.5 186 4.b 143 5.4 04h b.b 343 5.1 185 4.8 297 8.7 G87 19.6 PS 14 .6 177 9.7 164 4.9 2qs RES. \II MD SPD. lt/S AVG . \liND SPD . ~IS 11AX. GUST DJR. OEG 1.0 1.7 183 .5 1.7 138 Hll .4 .8 .5 2.5 1.3 .6 1.6 1.1 1.2 1.2 1.4 1.0 2.4 C' • .J .3 ., ,, 2.0 2.4 1.5 1.8 .4 .7 ,8 .6 .4 3.5 1.2 3.1 .5 1.1 I .6 1.2 V3 1.5 1.3 2.7 2.2 1.8 1.5 2.2 1.9 2.9 1. 4 !.b t.b 3.5 3 . g 2.0 2.5 2.5 2.4 1. 9 ~ .1 1.9 4.0 2.4 4.2 2.2 *** 170 343 3?.7 J42 148 205 177 ?&2 181 228 137 171 175 26 4 159 264 ?33 263 164 143 110 298 223 140 122 160 177 130 tbO GI.J<H I,JI:::L.. GU ST '·JF.:L. Gl.l ~n '.JE L. G U ~T 'JF.:L . AT MAX, (~LIST M I NIJ!3 AT MA'x. GUST MINUS AT MAX. ~US T PLUS AT MAX. GUST PLUS MAX. GUST ? 'VAL MEAN SPD. DJR. RH !1/S % !lEAN DP DEG C PREf.IP i1" 8.3 ssw ** llllf 0.0 9.5 w ll ***** 1.2 lUI !Ill 4,4 Sl~ 5 .7 NNW 3.8 N 7 . 0 NNW 4.4 tlNII ~.4 ~~~ 7.6 5 6.3 NNW 8.3 ssw 5.7 ssw 7.0 s 5.7 ~NW s It. 4 7' 0 ssw 7.0 II 6.3 N 9.5 NNW 10.8 ~SII 8.3 SSE 12.7 SE 8.9 Nti\ol 7.6 N 9.5 s 7.6 NNII 11.4 £ 17 .1 ~~ It. 4 S 17.1 SSE 17.1 NNW n ***** U Ul*' U HHI H IHH U Hill Ill ***** U HIH H IIHI ** ***** ** ***** II 41HI U IHH .... **"* fi iUH ** *"'*** n ***** lll 'fHH n *"** H HUll llf liUH II Hill ** HHI H HIH ** ***** II fHH H l HH H HHI H UIH ·H ·HUll H Hill 2 T NTFR ~.'AI S INTERW~L ·1. INTFR 'JAL -:> [N T E R~)ALS ***' 0.0 0.0 0.0 u 0.0 0.0 0.0 u 0.0 u 0.0 u 2.0 1.B 0.0 ~.0 0.0 u .B 1.6 0.0 u 'l .... u Q,O u 0.0 u 7.6 1 fl . ;~ 1 0 . ~~ 1l. 4 7.6 DAY'S SOLAR FliERGY DAY WH/Sw" 67"!5 3'540 2 "**** 3 5198 4 7088 '5 5500 6 1,803 7 7570 8 6715 '1 7553 10 7473 ! 1 4560 12 5903 13 5303 14 6318 15 4553 16 3220 17 3905 IB 5898 19 5383 20 40313 21. 4783 22 4735 23 5093 2.1 6~23 ~5 3785 26 4803 27 4000 28 4430 20 5753 30 40 43 31 160899 N!JiE : f<EI...AiiVE HUM TD TTY ~~EADJNCS ARE UNR FI.. I AB i..E I..JI-11:::1··! I...JTND ~WI='F D S AI~ I;: I FSS Tlh~N ON~ MF.:TFR PF.:R ~~C!J ND. S UCH READINGS HAV[ N!JT BE EN IN~I...UDED IN THE DA I I_Y 0 1~ WJNTHI .. Y t1F.,~N Ff)l~ I?ELA TTVF HIJI1TTHTY ANJ) DFI.·' PnTNT. **** SEE NfJTF.S AT THF. BA CK n F THI S RE POR T **** 143 I~ &. M C CJ N S U L. T ANT B , :t: NC . S US :1 : T N A H Y D I ~ DE 1 ... E C T I~ :1: C P I~ Cl .T E C T 110NTHL Y SU MMAR Y FO R WATA NA WEATHER STATION DATA TAKEN DURING S ep teMbe r .· 1982 RES. RES. AUG . IIAX. !lAX. DAY 'S MX . IIlii. !lEAH \liND Iii MD \liND GUST GUST p I Wl. IlEAl! !lEAN SOLAR DAY TEMP . TEltP . TE!f. DIR . SPD . SPD. DIR . SPD . DIR . RH DP PRECIP OtER'Y DAY fiE(; C DEG C DEG C DEC 11/S 11/S DEC 11/S I DEC C Ill\ IIH/S~ 1 11 .1 2.& u 858 .7 1.4 145 5.1 N H ..... .2 349ti 1 2 11.3 t.2 6.3 250 .7 1.9 247 7.8 E .. HHI 2.2 3938 2 3 7.1 2.1 4.6 337 .4 1.1 251 5.7 N H Hilt 8.2 2098 3 . 4 11.5 .7 5.6 059 .8 138 4.4 u 4485 4 I 1.6 N H ..... 5 13 .6 2.9 8.3 179 5.6 5.8 894 14.D E H Hill .8 2191 5 l b 14.5 5.9 11 .2 078 2.8 3.5 182 ".2 E II tltlt 1.2 2930 & .j 7 9.9 5.1 7.5 269 2.8 2.9 ~ 7.8 \1 H tttU 4.4 2865 7 I 8 7.4 4.9 6.2 2b6 t.b 1.8 271 4.4 \1 H IIHI 2.2 1490 8 9 8.8 4.b b .? 089 1.7 2.1 087 8.3 E H fHII 4.b 2265 9 I 851 t.2 1.5 067 0.1 2220 18 ' 11 8.5 3.4 6.8 4.4 N H ltHH I 11 &.b .b 3.& 257 1.1 1.9 255 8.9 \1 H ..... 12.0 1b95 11 12 7.b -.6 3.5 881 2.4 2.8 07& 10.8 E H litH 2.6 3743 12 I 13 12.1 1.4 b.8 163 2.3 3.7 055 8.9 ENE H ..... 18.b 2195 13 14 7.8 5.2 b.5 079 1.7 2.a 073 7.0 OlE H tiiH 12 .& 1185 14 I 15 9 .1 &.& 7.9 854 3.5 3.!. 869 7.6 HE It It HI ?.b 542 15 lb ..... litH ..... IH IIH Hit IH IIH IH .. IHH UH ...... 1& 17 7.9 6.1 7.0 29o 1.1 1.3 330 3.2 IIHW It IIIU i.O 98 8 17 -18 11.4 b.O 8.7 078 2.1 3.2 Ill 8.9 E .. ..... 8.0 ms 18 19 8.1 2.& '5.4 2&9 1.1 1.S 2'51 5.7 \1 It ..... 4. 8 1411 19 29 i.3 2.4 4.9 353 .1 1.3 238 4.4 II .. . .... .6 21 45 2Q I I 21 18.2 2.1 11.2 Q79 2.4 3.9 188 11.4 E H Hilt l.b 1413 21 22 b.'S -1.1 2.7 296 1.2 1.9 248 7.& II H IIIII 1.1 2720 22 23 6.7 -4 .1 1.3 325 .8 1.7 226 '5 .1 II It ..... 1.0 3958 23 i 24 7.9 -5.b 1.2 m 2.2 2.3 175 7 .a E If ..... u 29&0 24 l I 25 11.2 -1.1 4.& 058 1.4 1.9 078 7.8 E H ..... u 2745 25 I 2& 5.2 .9 3.1 32& .& 1.5 145 5.1 IIHW If IIIII 2.8 1798 26 I 27 6.3 -2 .1 2.2 285 l.b 2.2 2&9 7.0 II It tHH .6 2755 27 28 3.1 -4 .3 -.6 17& 4.3 4.4 1183 9.5 ENE .. . .... 2.0 1598 28 II 29 4.7 .1 2.4 171 2.8 3.1 092 1.b liE H ..... 5.8 1731 29 30 2.9 -1.1 .9 274 .b 1.1 261 3.8 II It Hill 4.4 1508 30 ! ttOHTH 14.5 -5.6 5.1 162 .9 2.4 094 14.0 E Itt IHH 118 .8 67248 i I I GUS T VEL . AT MA X. GUST MINU S 2 INTERVALS 10.8 GU ST VEL. AT MAX . GUST MINUS 1 INTERVAL 9 .5 GUST VEL . AT MA X. GUST PLUS 1 INTER VAL 11 . 4 I GUS T VEL . AT MAX . GUST PLUS 2 INTERVALS 10.2 NOT r.: RELATIVE HUMID I TY READING S ARE UN RELIABLE WHEN WINO SPEED S ARE LESS THAN I ONE METER PER SECON D. SUCH READ INGS HAVE NOT BEEN INCLUDED IN TH E DAIL Y OR MONT HLY ME AN FO R RELATIVE HUM I DITY AND DEW POINT. ·~···~'k SEE NOTES AT THE BACK OF THIS REPORT lHt*·X· I I 144 I ·~ ~ M CONSULTANTS> :a:Nc. I SU~!) :t: TNA H Y l) I~ Cl E 1... t::: C T I~ :1: C F''l~ DSECT I MONTHLy SUMM ARy FOR WATANA WEATHER ST ATION DATA TAKEN DURING Oct ober , 1982 t ) RES. RES. AVG. MX. MX. DAY 'S I MX . IUN . I£M vum VIM> vnm GUST GUST P'Wt. HEM I£AH SOLAR DAY TDIP. TE!f . TDIP . DIR . SPD . SPD. DIR . SPD. DIR. RH w PRECIP BOGY DAY DEit C DEG C TGC KG IVS lt/S DE It !VS % DEC C "" WK/SQil 1 3.7 -2 .1 .a 218 '1 .& 271 3.8 S£ H HIH I .I 1831 1 2 2.2 -2 .0 .1 162 .9 1.1 111 4.4 " H IHH 1.1 2278 2 3 1.8 -2 .& -.4 152 2.2 2.4 131 &.3 liE H HIH . 4 1481 3 4 1.9 -3 .3 -.7 149 3.3 3.4 146 7.& liE H fHH 1.0 2891 4 5 -.1 -3.5 -1.8 141 4.1 4.1 ·~ 8.9 liE H HHf 1.0 2781, s 6 1.1 -3.5 -1.2 149 4.3 4.4 OM 8.3 ME If HIH ••• 2105 6 7 -.8 -3.8 -2.3 1119 3.3 3.8 173 8.9 EHE H HHf 1.0 985 7 8 -2.3 -5 .7 -4.1 261 3.8 3.5 265 8.9 II5W II ffiH ••• 2229 8 9 -1.2 -18.9 -&.1 276 1.4 1.6 257 4.4 v H IUU 1.0 1468 9 u -.9 -7.3 -4 .1 297 .& 1.1 2&& 3.8 v H HHI 1.1 1885 11 11 -1.9 -9 .9 -5.9 HI HH 3.5 HI HH HI H HHf .2 931 11 12 1.8 -4.2 -1.2 162 4.4 4.& I '](! 11.4 El£ H HHf .2 1181 12 13 -3.3 -1 8.1 -11 .7 152 1.5 2.0 829 8.3 N It "*" ••• 1435 13 14 -4.1 -14 .5 -9 .3 868 1.7 1.9 196 5.1 E H fHH 8.1 1513 14 15 -4 .1 -17 .2 -U.& 839 1.8 2.2 073 7.& M H HIH 1.1 2619 15 16 -3.2 -11.3 -7.3 167 5.1 5.1 186 11 .2 ENE H Hflt I .G 1821 16 17 -.s -7.& -4 .1 112 1.1 1.4 117 3.8 HI( H HID 1.8 1b41 17 18 -.3 -11.0 -5.7 83& 1.2 1.5 346 3.8 N " II HI 8.1 2111 18 19 5.1 -&.& -.8 0&5 1.2 1.5 037 3.8 E H IHH 1.0 1856 19 20 4.1 -4.7 -.3 852 2.3 2.7 126 8.9 ltHE If if*H 1.1 IUHI 21 21 -.1 -7.5 -3.8 144 4.7 4.9 136 8.9 liE H IIHI I. 0. *"*" 21 22 -3.3 -12.1 -7.7 852 5.9 6.0 159 18 .2 ME .. HIH 1.0 HIHI 22 23 -4.5 -1&. 0 -18.3 863 5.5 5.7 843 8.9 EHE H HIH 1.0 ftHII 23 24 -6 .4 -1&.8 -11.6 U&& 4.U 4.2 8~ 8.9 El£ •• II HI 1.1 IHHI 24 25 -4 .1 -14.11 -9.3 186 2.2 2.5 151 6.3 atE " IHII 1.8 ...... 25 26 -11.1 -22 .7 -1&.9 181 3.2 3.& Orl 8.9 E u · HHI ••• IIHH 26 27 -17.3 -21 .9 -22.& 154 2.7 2.9 .82 8.3 EHE H Hltl 1.8 1551 27 28 -16 .2 -21.2 -18.7 872 3.9 4.1 172 9.5 EME H "*" 3.1 731 28 29 -11.3 -22.3 -16 .3 312 .7 1.4 lU 3.2 IIHW H "*" .4 1515 29 30 -15 .1 -32 .8 -24.1 IIH IIIII l.b IH .... HI If fHH O.G 1488 38 31 -13.1 -24.3 -18.7 056 6.2 4.4 IS& 11.2 t( H fHH 1.0 1135 31 ~NTH s . 1 -3C..B -7 .& 850 2.7 3.e 119 11.4 E1IE II HHI 4.2 38729 GUS T VEL. AT MAX . GUST MINUS 2 INTERVALS 8.9 GUST VEL. AT MAX . GUST MINUS 1 INTERVAL 7 .6 GUST VEL. AT MAX . GUST PLUS 1 INTERVAL 8 .9 GUS T VEL. AT MAX. GUST PLU S 2 INTERVAL S 8.9 NOT E: RELATIVE HUMIDITY RE AD INGS AR E UNRELIABLE WHEN WIND SPEEDS ARE LESS THAN ONE METER PER SECOND . SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAIL Y OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. ·Xo ·.:<-*'* SEE NOT ES AT THE BACK OF THIS REPORT ~H~*·~ 145 ~:> U G :t: T N A H Y D I ~ U E 1... E C T I ~ :1: C P F~ U S 1::: C T MO NTHL Y SUMM ARY FOR WAT A~ WEATHER S TAfiON DA TA TAKEN DURIN G No ve Mber , 1 9 8 2 RES . 11AX. 11IH. HEAH WIND RES. AVG. IIIHD IIIHD SPD . SPD . 11/S 11/S DAY TEMP . TE)'!P. TEl1 P. DIR. DEG C DtG OEC C DEC C • 1 -3 .0 2 -1.4 3 -4.3 4 -4.3 5 -e. 4 b -11.3 7 -1:?.& 8 -11.2 9 -8.2 10 -8 .3 11 -s . 4 12 -1.6 13 -1.5 14 -4.2 IS -5 .8 16 -10.2 17 -ltd 18 -!4 .5 19 -16 .8 20 -13 .:, 21 -b . 0 22 -5 1 23 -2 .7 24 _, .& 25 -J.3 2& -5.8 27 ·3.8 28 -7 .:? 29 -:. ~ 3C -~. 9 t\ONTH -1.4 -14 .9 -10 .9 -13 .4 -9 .:? -15.7 -20 .5 -21.9 -1&.5 -18 .5 -16.7 -9 .5 -7.1 -&. 0 -10.2 -1 7.& -19.4 -22.7 -:!4 .5 -24 .7 -1 7.9 -IS .1 -\1 .2 -5 ,5 -4.2 -1 0.9 -1 \.b -14 .5 -1 6.6 -9.4 -!~.2 -24.7 -9.8 -6 .2 -8.9 -&.8 -12.1 -15.9 -\7.3 -13.9 -1 3.4 -12.5 -7.5 -4 .4 -3.8 -7.2 -11.7 -14 .8 -19.5 -1?.5 -:?0 .8 -t5.b -!0.9 -9 .2 -4.1 -2 .9 -7.1 -8.7 -9.2 -11.9 -8.2 -t I. 1 -!9.7 072 066 071 ObO 052 005 Ob 4 064 302 064 Db3 0&6 054 025 Ob5 07 5 077 Obb 070 091 Obi 056 356 058 07& 0&2 Ob6 07 1 oss C35 06 3 6.3 1.5 2.7 4.0 :?.3 1.2 3.6 4.3 .8 3.9 1.9 5 .9 3.2 1.2 1.5 1.7 :?.3 2.8 5.7 2.4 3.6 1.8 4.3 4.5 4.5 5.7 2.3 \.b 7 \ w o"t 3 .9 3. i 6.4 2.8 2.9 4. I :?.~ 1.4 7 ., ..... 4.8 1.:? 4.0 2. 0 &.0 3.6 1.3 1.7 I .8 2.3 3.0 5.8 2.5 3.S 2.0 4.4 4.5 4.& 5.7 2.4 1.7 3.5 4.1 3.3 GUST ~E L . AT MAX. GUST GUST VEL. AT MAX. GUST GUST VEL . AT MnX. GUST GUST VEL . AT MAX . GUST MAX . GUST pI VAl MEAN l'ltAN PIAX. GUST DIR. DEC SPD. DIR. ~H DP PR £CI P 073 064 076 068 057 0 4~ 064 064 288 067 075 082 086 009 089 073 073 391 074 071 052 051 059 092 OBI 067 DeS Ob O e:s 030 073 MINUS MINUS PL US P L US tt /S ! DEG C M~ 14.0 ENE 6.3 E 7.6 ENE 10.2 E~E 5.1 NE 4.4 E 9.5 ENE 11 .4 E.HE 5.7 WNW 9.5 ENE 7.6 ENE 12 .1 ENE 8.9 HE 3.2 H 4.4 ENE 5.7 ENE 4.4 E 8.3 [.'{[ 11 .4 ENE 7.6 E 7.6 NE 5. I E 7 .0 ENE 7 .a ~E 9.5 ENE 10.8 ENE 7. 0 ENE 4.4 E 7.6 NE !~ .2 ~!llE 14.~ ENE H U I H u ntH U HUf H! XH!!li !l! UHf n Hli!l* n ***" H U!lll H U UI U UIU l!f UIU 68 -9.1 73 -7.3 H I~H 68 -14 .9 72 -20 .4 63 -25 .1 47 -28.9 46 -28 .6 52 -::3.2 58 -16 .4 62 -14 .0 71 -8.5 !I H H!I 73 -11.6 66 -\3.9 73 -9.2 ill *l!!IU U Hif.Jf: 77 -!b .~ 62 -16 .5 2 INT E I~Vrt L S 1 [r!TER \Hd_ 1 T.NTER'.lf."'L 2 HlTERVALS u 0.9 0.0 o.o 0. 0 ~.0 0.0 0.0 u ') o.e 0.9 0.0 0.0 u 0 .~ 0.0 ~. J u e.~ OJ • 0.9 0 .I 0.0 0.1 0.~ 0 .o 9.9 u u ? .. , ., . -.. 11 . 4 1 3.3 12. 1 DAY'S S!JLAR t i!ERGY DAY WHi sml toa ~85 588 913 9~5 :~29 !515 C"')-w~.l 495 2 3 5 7 e 9 573 !0 641 1! ~0 !2 64 J 13 798 \~ 921 15 t 003 16 991 17 ! 003 18 7PS 19 ~05 20 52t 2! 459 22 43S 2 3 62~ 2 ~ s ·~ :J 55.1 26 518 27 558 28 385 29 21 573 ~IDTE : RELn TEVE HUM IDITY RE ADIN GS ARE UNRELIABLE WHEN WIND SPEEDS ~RE L~S 3 TH~N ONE METER PER SECOND. SUCH READINGS HAV E NOT BEE N INCLUDED IN THE ~~IL Y OR MONTHL Y MEnN FOR RELATIVE HUMID I TY AND DEW POIN T. ~*»* SE E NOTES AT THE BACK OF THIS REPORT **** 1 4 6 & M C D N ~:> U L. T i~ NT ~:> :• ,'\Or•T:-it 1 :.1U MMAKY FOR wA"i=~NA WEA Ti-t ER STATIGN DA fA TAkEN Du RI NG Dece Moer ~ 1 9 8 2 DAY IIAX. iEi"i. atr. c ,. nih. TEMr . DEi. C IIEAH Taw. fiEf. C itS. WIND DIR. DEG RES . WIND SrD . 11/5 AVG. WIIiD SPD . rii S i'IAX. GUST iliR . DEG riAX, GUST P'V AL MEAH SPD . Dii . ~ri titS 4 :J:NC. I'IEA!i DP PREC lil DEG C r!n IIAY 'S sow EriEiG'f ~AY IIH/Swn ----------------------------------------- 1 2 3 4 5 6 7 8 9 10 ll 12 13 14 \5 iii 17 IB 19 20 ~~ 22 23 24 25 j " ... o 27 28 2.9 30 31 hiiNi n -14.4 -17 ' l -17.7 -15. I -7.4 -5.3 -.? -1.0 -2.4 -a ,3 -7.o -5 .8 -3.3 -2 .9 -2.8 -4.5 -o.2 -7.3 -a.7 -8 .9 -1'!.& -14.4 -1 ~.3 -9 .4 -11.o -2.5 .4 2.i 2..o -1.6 -4 .1 2.i -19 .7 -23 .9 -24 .2 -24 .1 -15.o -1 6.8 -5 .9 -~.a - -17 .2 -18.4 -10.2 -9.2 -6.9 -10.8 -\D.o -11.& -1 2 .~ -15.1 -H .b -17 .5 -2U -2 2.7 -~u.iJ -lB . a -\&.1 -13.4 -3.G -.3 -3. i -11.6 -1~.5 -24.2 -17.1 -2&.5 ··21 .0 -19.6 -11.5 -8.1 -3.4 -2.9 -9 .8 -13.4 -8.9 -7.5 -5 .1 -b.9 -o .7 ·8.2 -9 .2 -11 .6 -11.7 -\3.2 -\8.4 -18 .& -1 7.2 -13.7 -14.9 -8.0 -1.7 -.3 -b.7 -8.3 -l il.4 032 070 065 Ob3 fl b1 057 082 679 059 07b 0&3 Obb 670 077 ubC! 665 uoa Obi 059 Ob6 077 075 1162 m, 073 062 083 078 088 Ob1 oaa 5.5 5.3 4.5 S.o b.b 6 .5 7 . I 3.6 .8 3 .4 o.o &.8 5.7 3.o 5.3 5.5 ;:l -~·J 3. I 5.7 4.2 . ") '·~ 4.2 5.5 3 .3 3 .1 &.o 5.i 4.1 3.4 .I 2.3 4.4 5.7 5 .4 4.8 5.& b.7 6.b 7.2 3.8 2. ~ 3.5 6.7 7. I b.O 3.8 5.4 s.o 2.4 3.1 5.7 4.4 2.3 4.4 5.6 3.4 3.3 6.7 5.8 4.2 3.7 1.9 2.5 4.i 025 071 07 4 063 062 u57 089 u79 279 060 Oo7 ij8 4 ~7i 091 iJi4 075 654 uo7 fl 55 •i 49 [J iJ9 u79 iJ &1 053 055 u78 098 il 80 075 2o5 u50 089 10.8 NNE 10 .2 EN£ 9.5 ENE 10.2 ENE 10 .2 ENE 12.1 rtE 14 .o E 12.1 ENE 7.0 EN£ 8.9 E 13 .3 ENE 14.0 ENE 12.1 ENE &.9 E 9. 5 EllE 12.1 ENE. 7.o t i.b ENE 10.2 EiiE 9.5 ENE S.i Ei'i E 9.5 Et.E 9.5 ERE 7.6 E -9.5 E II. 4 ENE 12 .7 c: 9 .5 E 10.2 E o.~ E 7.u EhE 14.6 EriE 6o 59 bO ou 72 b9 86 u It o6 66 69 u 70 7Q 70 i 5 H 69 65 83 74 o4 69 85 78 u ** u -i1 '9 -24 .8 -2il .3 -25.o -IS .l -1 3 .4 -8 .4 HU~ U:lltt -15 .5 -14.3 -12 .4 IUU -1 2.1 -9.2 -I!. 0 -10.5 HH• -15 .9 -l i.o -21.4 -22.4 -21.2 -18 .3 -1 7.5 -13.b UfH -HU11 UU~t kHd u~J:l -1o.7 Q,O 0.0 .2 0.0 u. 0 .a 2.8 .4 a. II 0.0 1.0 6.9 8.0 o.a 8.0 0.0 & • 0 o.u O.il u U J o.a u u O,ij 11.0 0.0 2.8 u o.o 9.0 7. u GUST V~L. AT ~AX. GUST MI~U ~ 2 I NTERVALS 10 .8 G~ST VEL. AT MAX. GUST M l ~~S 1 I~TER~AL 12.1 GU ST VE L. AT MAX. GUST PL~S INTERVAL 12.7 GUST ~EL. AT MA X . GU ST P LU S ~ l~TERVALS 10.8 44d 1 498 2 -'183 3 4o3 4 39~ 5 458 0 j5lj :io a a 12u 9 375 10 345 l l 366 12 IiS 13 358 14 383 IS 3au 16 355 17 3a 3 1a 35~ 19 41 0 20 -\o~ 2. 475 22 40 5 23 390 24 385 25 356 2o 31)3 27 290 28 .i48 29 313 j ~ 4uli 3i 12aoil NG TE : ~E LR TIV E HUMI DIT i RfADi NG S A~E UNRE L IABLE Wh EN ~I N D SPEE DS A~E LESS TnAN ONE METER PE R SECON D. SuCH REA DINGS HAVE NOT BEEN INCLU DED IN THE DALLY GR MG hTHLY MEA N FOR RE LA TIVE hUMID ITY AND DEW PO[NT . ••~» SE E ~GTES AT Th E BACK OF Trl iS REPO~T i*** 14 7 :t: N C . S U S :t: T N A H Y :0 I ~ D E L E C T I~ :1: C P I ~ 0 ,T E C T MONTrii .. ( SUM Mi4 Ri FO K wATANA \li EAi Ht:R STA T ION DATA TAKEN DuKING January) 1983 ( RES. Rt:S. AVG . IIAX. !lAX . vAY 'S !lAX. rH ri. ntAM iil HD "HiD Ill MD GUST cus T ? 'v ~ KEilll IIEA N Su LAK DAY iEi1P. TEMP. TEJIP . Dli . SrD . srn . DiR . SPD. DIR . ~H DP PREC i P ENt.KGY DAY ... l DEG C DEi; C fiEG C DEG IVS IVS DEC M/S % DEC l. 1111 1111/51:1~ / . r , ----'-·-------·-----------·------------_, -.J <. ~. 4-:---1 . u -5.7 ;;.1~9' Ob4 5.3 5.4 072 10.2 EN£ u IUh 6. 0 425 I 2 -4 .2 -7.1 -5.7 062 4.6 4.8 059 6.3 ENE tf fHH o.o 410 2 3 -o .b -11.5 -9.1 053 4.7 4.8 GSJ 8.3 ME 58 -17 .3 l.b 348 3 4 -1 0.o -25 .7 -18.2 076 3.1 3.3 080 7.0 E 51 -25 .7 0.8 495 4 5 -2iU -28 .o -24 .4 091 3.o 3.7 Otib 7.u E 55 -30 .9 Q.O 415 " ..1 0 -2 0.o -26.1 -23.4 951 o.O 6.2 a4o 11.4 liE 54 -28.11 o.o 435 II 7 -22.1 -27 .2 -24 .7 &52 5.9 b . 0 0112 12 .1 HE Sb -30.3 0.6 4{)8 7 6 -21 .a -28.b -25.2 07b 5.0 5 .3 ObO 10 .2 ENE 54 -32.8 u 515 8 9 -2 7.0 -34 .4 -39.7 088 2.9 3 .I 07 8 8.9 ESE 51 -37 .5 0.0 518 9 10 -27.5 -2 7.5 -27.5 ~93 4.5 4.5 693 7.0 E 55 -33.8 U H 240 10 11 -17.9 -2 £1.8 -19.4 ust 4.0 4.9 010 8 .9 t 28 -34 .4 0.0 240 11 12 -2 6.5 -25 .il -22 .8 0112 5.8 5.9 052 10.8 ENE 49 -32 .7 u 598 12 13 -21 .1 -25.2 -23 .2 ir iiS 7.2 7.3 059 13 .3 84£ 4i -32 .5 9.6 573 13 14 -14 .1 -24.6 -19 .4 Ob8 S.il 5 .2 Ob9 1\.4 tHE 49 -27.il 0.0 SuS 14 15 -4 .9 -20.9 -12.9 Oo9 3.9 4.1 0112 9.5 ENE bi -19.3 a.u 45ij 15 16 -o .1 -10 .2 -8.2 Olio 4.8 4.8 ObO 10.2 ENE b5 -13 .7 o.u 485 16 17 -5 .8 -12 .11 -9 .Z i44 z.o 2.3 ij b7 8.3 ~ 70 -13 .3 u 475 17 18 -4 .~ -b .9 -5.b 057 5.9 b.2 075 12.1 ENE b8 -1 0.4 u SoO 18 19 -b.il -liLY -6.5 Obo ~ ·"' 2.8 072 9.5 E.llE llfs -12 .9 1.2 4~ 19 2il -S.il -ta.s -9.3 047 5.5 5 .5 Qb1 8.9 NE b7 -14.2 0.0 5&5 20 21 -7.4 -15 .2 -11.3 047 5 .1 5 .2 OSb 8.3 liE 4& -19.4 u 726 :!1 22 -3.8 -17.2 -10.5 uib 3.o 3 .7 083 9.5 ENE 39 -22.7 O.Q 7&0 22 23 -b.O -1&.4 -11.2 075 3.11 3.7 070 8.3 E 31 -211.7 0.0 79& 23 -. '~ -a.~ -1 ~.7 -11.1 li b2 o.ir b.2 Gb3 i2 .l ENE 33 -24 .1 u 815 24 25 -8 .7 -14.& -11.7 u&s 7.4 7.5 Ob5 i 3.3 ~ 39 -23.8 u 75v 25 26 -b .7 -11.3 -9 .1) Gb9 7.4 7.b Ob5 14.& ENE 52 -1&.9 0.0 &48 2b 27 -o .b -13.6 -16.2 072 3 .1 3.3 075 9.5 ENE 64 -15.0 0.0 598 27 28 -·1.7 -1a .i -7.7 070 1.4 l.b 095 3 .8 E u ..... 0.0 b93 28 29 -8.1 -15.6 -12.0 073 2.2 2.4 097 5.7 E 75 -14.8 u &88 29 ,)~ -o.1 -i4.2 -lii. 2 J58 o.4 b.4 ~57 111 .2 EN£ 77 -12.o u 65J 3u 3\ -2.2 -o.1 -4 .6 0&3 .. . ,J,, 5.4 675 10 .a EHE bb -9.8 o.u no 31 rruliin .A ,~. -~4.4 -1 4 .I uo4 4.5 4.8 ObS 14.& ENE 53 -22.6 2.8 17675 cu::l r '· fi_. AT 1"1 (-) ;( • GUST M.i.N Li S -., .... INTE RVAL S 1 I . 4 GUS I '" t. i_ • AT n ?l .x.. GUST MINUS 1 I NTE RVAL 14. l) GJ E>T vEL. 1-\f nr~X. GuST p,_us 1 I NTERVAL 1 4. 0 Gu ST VE.L. AI rlA.-\. GUST PLUS 2 I NT ERVAL S ! 2. 1 NUi't:: f<ELAT:i>)t: HUM iii .;:!"( Rt::ADII'lGS ARE UNKEL I AB LE WHE N WI ND SP EE DS AI<£ LE SS TH AI'' Jr~E METER PER SE COND. ;:)uC.H R t:AD I I'!GS HAV E NO T BEE.r~ INC LUIJED 11'1 THE lJA 1 Lr uR ntJI'Y TrlLY M Et'o~N 1=-0R Rt:I_AfiVf.: HU MI-;)ITY AND DE w PO I N i. ;<; }: ·t.: 1< SEE ;~DTES f-lT T t-it:: BACK GF THIS REPORT ·Xo ·X·-Xo·~ 1 48 ·~ ~ M C 0 N S l .J 1... T A N T S > :a: NC. S l.J S :a: T N A H Y 1) I~ D E 1... E C T I~ :a: C PI~ Cl,TECT MONTHLY SUMMARY FOR WATANA WEATHER STATION \ DATA TAKEN DURING February , 1983 RES . RES. IWG. MX. MX . DAY'S MX. MIM. I£AM Iii MD lilt& li!lti GUST GUST P'VAL !'£AN ION stiLAR DAY TEMP . TEitP. T£MP. DIR. SPD. SPD. DIR. SPD. DIR . RH DP PRECIP EHERGY DAY KI:C KG C IG C DEG MIS M/S IIEG IVS % DEG C lilt liiVSQit .3 -u.2 -S.I 1119 4.8 5.1 lb9 13.3 ME 59 -u.s ••• 913 1 ' -1.7 -5.3 -3.5 1&3 5.3 5.5 871 11.8 a£ 77 -7.3 1.1 S"~ , .. 2 3 -2 .8 -5.7 -4.3 059 S.D 5.1 174 11 .8 ME b9 -9 .3 1.0 813 3 4 -2 .7 -o.3 -4.5 171 5.5 5.o 177 12.1 a£ il2 -11.8 1.1 83:. 4 5 -2.4 -9 .4 -5 .9 aoa 4.7 4.9 87t 14.1 EJtE ot -11.7 1.0 nas 5 0 -1.7 -10.7 -o.z IM 4.o 4.9 061 11.4 EHE 04 -9.3 ••• 1181 0 7 -4.4 -7 .4 -5.9 028 .9 2.5 D77 8.3 WHII 7o -8.8 1.0 931 7 8 -5.1 -13.5 -9 .3 341 1.2 1.4 290 3.2 M H ""* ••• 087 8 9 -7 .5 -15.9 -11.7 1&3 1.2 1.7 180 8.1 E o& -17.S 1 .~ 783 9 11 -11.1 -17 .4 -14.3 174 1.7 1.8 079 5.7 E 08 -18.1 1.8 7S1 10 11 -13.o -21.8 -17.2 87S 2.1 2.4 073 5.1 E 08 -22.4 1.0 828 11 12 -12.7 -22.9 -17.8 174 1.9 1.9 09o 5.1 E M -24 .(, ••• 935 12 13 -14.8 -25 .4 -2&.1 0&3 1.7 1.9 too 3.8 ENE 63 -27 .3 1.0 1912 13 14 -13.2 -25.4 -19.3 072 2.8 2.9 073 8.9 DE 59 -24 .7 ••• 1973 14 15 -11.4 -15 .1 -13.3 17o 7' 1 7.1 978 11.4 ElE 52 -21.1 0.0 1558 15 l b -12 .0 -15.3 -13.7 173 8.0 8.0 176 11.4 E'HE 47 -22 .4 8.1 1&31 16 17 -14.0 -19.4 -1o .7 177 o.o &.7 876 11.4 E1tE 45 -25.o 1.0 1085 17 18 -11 .9 -18.0 -14.5 p~ 7.1 7.2 105 11.4 Ei£ 50 ·21 .7 1.1 1245 18 19 -5.1 -t3.o -9.4 lSi 4.1 4.2 861 8.9 EME 73 -13.o 1.0 1691 19 21 -5.8 -12.9 -9 .1 lbb S.b 5.7 177 9.5 DE bl -14.3 u 1741 21 21 -4.1 -12 .3 -8.2 067 4.U 4.1 lbb 8.3 ENE sa -14.1 a.o 1845 21 22 -1.1 -11 .8 -o.s 803 3.8 4.0 005 9.5 a£ 65 -18 .9 1.0 1920 22 23 -3.7 -12 .3 -a.t 106 5.o 5.7 oot 11.4 Eli£ so -14.3 u 1908 23 24 -3 .4 -8.6 -o.o 858 2.9 3.2 168 15 .2 El£ 7S -9.8 l.i 1253 24 25 -3.& -14.4 -9.0 tot 3.7 3.1 tb2 6.9 I( 61 -12.3 1.0 2305 25 1 2b -4.8 -9 .0 -6.9 055 6.4 6.5 A6Q 18.8 ME 62 -12.6 1.8 2110 26 'lJ -3 .9 -12.8 -8.4 056 3.Q 3.1 OM 8.9 EME 61 -13.7 a.o ;em 27 28 -4.2 -9.2 -6.7 QS9 1.0 1.1 073 3.8 ENE bO -13.(, 0.8 1050 28 liOMTH .3 -25.4 -10.0 lOS 4.1 4 .3 @08 1S.2 EME o1 -15.6 0.0 38982 I J GUST VEL. AT MAX. GUST MINUS 2 INTERVALS 8 .3 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 8.9 I GUST VEL. AT MAX. GUST PLUS 1 INTERVAL 14.6 GUST VE L. AT MA X. GUST PLUS 2 INTERVALS 8.3 NOTE: RELATIVE HUMIDITY READINGS ARE UNRELIAB LE WHEN WIND SPEEDS ARE LESS THArl ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAILY OR HONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW PO I.H . *•X··X.·X. SEE NOTES AT THE BACK OF THIS REPORT -~·-*•* ) 1 149 1:.{ T i'-IC. ~:; l.J U :i: T N f.:·r H Y D I ~ D E L. E C:: T 1 ~ :&: C p 1 ~ U :r 1::: c ··, · rtur~ tt"1t 1 SLI MMAt< "( FOR i,.if-1TANI-1 WEriT11E F, STA T ION u AT H TAkfN DU ~lNG narch, 1 983 DAY 7 & 9 Iii i i 12 13 14 1i 18 19 20 2..2 2~ 24 26 28 29 30 31 MOri1H t\A},. TthF. u~~ : -2.b -8 .1 -1 i. 0 -1, ... -~ .b -o .5 -4.9 C' • -.~.o -i.& HH'I< HH* t.a u -1.3 -.i .o -.5 -.6 -1.0 -2 .8 -I.e -1.9 -2.5 -~.6 -2.4 -2.6 -u~ -2.u -1.£ -.5 9 1.8 riltl . iEh?. ii EG C -i~.o -17 .4 -21.j -20.2 -1o.4 -15 .4 -15.2 -17 .5 -2u.6 HUll tUH -1.8 -8.1 -tl .3 -8.4 -1.a -9.2 -7.1 -1U -7 .8 -9 .I -9.8 -11.7 -14 .9 -8.7 -8.9 -9.1 -13 .4 -lid -13.4 -10.i -21.3 r\EAit i Eh?. IJEG C -6.2 -12 .8 -1 t>.5 -lo.3 -12.1 -11. Q -10.1 -11.6 -14.2 UIU IUU 6.0 -4.0 -3.8 -4.6 -4.b -4.9 -4 .0 -6.6 -5 .3 -5.4 -5 .9 -7.1 -8.8 r • -.,.o -5 .8 -6.7 -?.i -6.1 -7 .0 -4.6 RES. IIIND OiR. DEl. un u34 u5 o 05 1 069 070 G53 074 on *** tU 042 054 052 043 H4 848 654 oou 059 054 054 032 058 058 055 ubi 048 &59 055 05i u57 ~ES. WI Nil sn . IVS 1.if I.e 4 u 3.3 3./ c -.J ,.) 2.o -~ .),_ 3.8 H H uu 3.6 4.1 ~ C' .... .~ 2.& . ' '-·~ 3.0 3.2 4.~ 3.3 4.~ 4-.2 2.4 3.~ 4.~ 5.4 b.o 3.3 3.6 2.7 2.8 3.5 AVG. II HID SFIJ . n t~ 1.2 2.0 4.4 3.8 3.6 5.3 2.7 3.2 3.9 H!ll uu 3.6 4.2 2.6 3. 0 2.3 3.2 ,),,) u 3.5 4.4 4.3 2.7 :; .1 4.4 5 .4 6.7 3.4 u 2.9 2.9 3.7 MAX. GUS T Di?.. EG u u~ YtlO 064 o;s 072 072 074 07 0 tfll IH 051 017 G66 036 o4a 011 u54 063 07 8 075 061 056 064 069 860 05:3 054 070 07 4 06i o7 u nA X. GUST pI V~l IIE.AN 11t.Atl 5?11. DiR . i!n iit .... ::: Ill ~ 4 . 4 tl ~. i tit.=: &.~ EhE a.3 m:. i .o Erlt. 10.2 HE 6.3 Etit i.b ENE 12 .": EliC: H H IH Hh IH 5.7 NE 6. 8 t itt 3.8 liE 6.8 HE 3.8 NC: b.2 NE 5.7 NE 5.7 NE b.3 [}l£ i. t> Er~~ b • .) NE. b.3 NE 6.3 NE ~.3 EIIE 10 .8 ttC:. 1 i. 4 E![ 7. 0 NE 8. 9 ENE 5 . ;· EKE t>.3 EriC. 12.1 EiiE lo 0 .> 00 bB 64 60 58 53 49 u tlt 53 50 56 6b o1 54 56 58 57 5j 52 50 5b 55 53 Si 54 58 bO b' 59 -1a .s -211.3 -1~.9 -lb.4 -15 .o -1t>.i -1~.5 -22.5 ***** un:.- -8.0 -i0.2 -1o.o -B.o -1 0.2 -12.1 -10 .8 -12.8 -1\.8 -12.i -1 2.9 -1 5.4 -13 .0 -13.1 -13 .5 -14 7 -13 .1 -1 3.0 -10.0 -14.0 rP.E CH M ttlt11: UH un flU lt'H .... H H .. , . H H uo lfH flU H it fit~ t nt **** H U flU "** **** H l!+- IIU tift **** U H tHf HU H llf ltH Ill* **** HU Gu ST VEL. AT MA X. Gu S T MINUS 2 I NTE RV AL S 8 .9 GUST VEL. AT MA X. GUS T MINUS 1 INTE RVA L l U.~ C.LJ'.:·T 'v'CL. ,.,, MA A . GLJS I PLL.lb It!TEI-.VAi_ B .S. C.,u2,. ·,-v:::.._. 1-t -i t-'1A1',. •.:,u~> -i P LU S 2 1 rH ER VA LS :; . ': i):,( ·; SOLAR 81E~GY DAY wri/Sun 1~3 u 245 u 2 274ll ~ m1 4 172:. ::: 2503 b ,&38 7 362:; 8 4227 9 ****** 10 ****** 1 i 39b0 12 291~ 13 co~5 14 1287 15 1o73 lo 3378 17 4926 18 24uC 19 4 10 2G 3471 2i 492 C 2.2 415? 23 3249 24 4i 12 25 39 63 26 422u 21 4320 28 4523 29 4ns 3D 450ii 31 900 91 :G .~: ~~L"1~0E nU .,I DITt ~~A DI N G S ARE UNRELIABL E WHEN WI ND SPEED S ARE LESS TH AN C.w: r _ i !:.• i' E~· SECOHl1. SUC h RE?;Dlr~GS H?,\.'E. rWl BEE!\: lr-!CLU[J[D It: THE l.Jti cL 1 L'• r~';··i··1L. r;r.::Hr~ l-OR ~:;::L ;~i.iVC. i-IUMIDI T'T 14 ND DEW POiNT. ... :.. ::. :. I .~I:::.~. ;, I T Hi:: :t.,., c:' 0 F 1 H j, :. REp 0 R T X:·)(; ·X:., 150 I~ &. M C 0 N ~:; U L T r.e N T ~:; .' :1: NC . MONTHLY SUMMARY FOR WATANA WEATHER ST ATION DATA TAKEN DURING Apr J.l. 1983 RES . RES. AVG . IIAX. l1t\X. DAY 'S MX. KIM. ltEAH III MD III MD III MD GUST GUST pI VAL ItEAM HEA.~ SOLAR DAY IDIP . TBIP. mw . DIR. SPD. SPD. DIR. SPD. DIR. iH DP PR ECIP EHERCY DAY DEC C DECC DEG C DEG K/S K/S DEG 11/S I DEG C "" liH/SQ" 1 1.8 -11 .9 -4.b 058 2.b 2.7 Db9 b.l EME 58 -9 .1 0.0 ~918 1 2 3.& -11.1 -3.8 ·~b 2.3 2.5 Ob8 7.1 ME 54 -11.6 8 0 SObS 2 3 .8 -11.3 -5 .3 •a a 3.9 4.1 171 13.3 ENE 59 -18 .s 0. 0 5138 3 ~ 1.7 -3 .9 -1.1 148 1.1 4 .9 274 14.& ENE bO -&.3 2.8 2143 4 5 1.0 -7.8 -3 .0 851 2.~ 2.8 073 8.3 ENE b3 -6.5 o.o 4013 s b .3 -19 .3 -5 .0 831 1.8 2. t U7 5.1 NtlE 58 -18 .9 8.0 5288 b 7 .b -10 .b -s .o 033 1.8 2. t 009 4.4 NNE 57 -1 t. 9 o.o 5383 7 8 2.2 -10 .4 -4 .1 051 .b 1.3 249 4 .~ NE 58 -11.6 0.0 ~303 8 9 2.& -10.7 -4 .1 322 .b t.b 278 5.7 H b9 -12 .1 .2 3473 9 li -4 .& -15.9 -10.3 028 1.9 2.1 022 s. t NE 54 -17 .7 0.0 5&53 tO 11 -8.2 -17.0 -12 .& Ob9 4.0 4 .I 078 10.8 ENE &3 -18.4 a.o 5&15 11 12 .4 -1.0 -.3 154 3.b 3 .7 069 5.7 EME 60 -o.9 0.0 10829 12 13 o.a O.Q 0.0 058 1.7 1.7 055 1.9 HE •• ..... 0. 0 7440 13 ~~ 5.1 a.a 2.6 033 1.2 1.4 035 3.2 NNE 46 -7.5 .2 13920 14 15 .I -3.2 -1.& 876 2.7 2.8 099 &.J ENE u IHll Q. 0 1271 15 16 1.~ -s .o -1.8 045 2.5 2.8 061 9.5 ENE 62 -b .O 0.0 4878 l b 17 6.8 -5 .8 .5 320 .9 1.7 245 7.0 IINW 53 -9 .9 o.a S&Oi 17 18 1.8 -4.2 -1.2 871 3.0 3.7 083 10.2 ENE 58 -7. t u ~oso 18 19 3.4 -3 .1 .2 057 3.0 3.9 079 11.~ ENE 47 -1o .a o.o 5:)71 19 20 3 .~ -4 .2 -.~ 067 2.9 3.2 OBI 8.9 ENE bO -7 .4 u.a 4740 20 21 3.7 -4.4 -.~ 0~4 2.4 2.7 080 7.8 rt£ 53 -&.3 0. 0 &108 21 22 &.5 -3.0 1.8 836 .9 1.7 &9~ 5.7 EHE 56 -~.8 a.o 5803 22 23 4.9 -2.1 1.4 302 .4 1.3 255 5.1 E 63 -2.7 0 . u SibS 23 24 8.3 -1.2 3.& 8~1 2. 0 2.2 076 &.3 HE 49 -4 .& 8.0 69&8 24 25 10 .1 1.3 5.7 052 2.b 3.0 86U 7.0 EN£ 51 -3 .4 0.0 7031 25 2o 8.9 -1.8 3.6 002 1.7 1.8 001 4.~ N 50 -3 .9 o.o 8238 2b ' 27 8.7 -2.2 3.3 336 l.b 2.0 2&5 &.3 N 49 -3.7 .2 6895 27 28 7.& -2 .8 2.4 344 .9 1.5 081 4 .~ N 57 -1.8 8.0 4610 28 29 b.4 .3 3.~ 275 .7 .9 219 3.2 II H UIH 0.0 4081 2) 30 7.7 -1.1 3.3 035 1.7 1.9 Otl 5.1 NNE 49 -8.3 0.0 7525 30 IIOKTH 18.1 -17.8 -1.1 045 1.7 2.5 27~ l~.b ENE 55 -8.2 ') . ... o 1717&4 GUST VEL . AT MA X. GUS T MINUS 2 I NTERVA LS 11 . 4 GUST VE L . AT MAX. GUST MINU S 1 INTERVAL 12./ GU ST VEL. Af MA'X. GUST PLUS l I NTE RVAL 14.6 GUST VEL. AT MAX. GUS T PL US ':> .... IN TERVALS 14 .U NOTF: RELATIVE HU MIDITY RE ADINGS ARE UNREL IAB LE WHE N WIND SPE::t:DS ARE LESS THA) ONE METER PER SECOND . SU CH REA DIN GS HAVE NOT BEEN IN CLUDED IN THE DA ILY OR MONThLY MEAN FOR RELATIVE HUMIDITY AND DEW POIN T. X··X· ·)(-l(· SEE NOTES AT THE BACK OF TH IS REPORT ·li;·X·~·* 151 1 •• , '< ·' •"':"":c M 1.:: 0 j" ... J ~:; 1 . ..1 1. .. T ,~:·, i'-J T ~:~ T i'-J C . MntHHLY S UMMARY :·no I,I ATANA l·JF A T I''.R S TAT HlN nArA TAKE N DURIN ~ M~u 1983 DAY tl!l~. TEi~P . DEG C 8.0 2 2 .1 3 3. 3 4 5. t 5 b. 0 b 7 . i 7 Ill. 0 a t t.t 9 9.4 I 0 i 0.2 It 11.6 !2 9.4 13 12.0 14 11.1 IS 11.1 16 9.6 18 6. 7 19 ? 8 20 ~**** 21 liHH 22 UliU 23 8.1 24 10.6 25 !~. 7 26 8.6 27 10.4 2R 15.6 29 17 . ~ ::0 20 .I 3: !2.1 HCltiTH 23. i HilL T(i'\P . DEG C -3.6 -.8 -!.6 -2 .1 -!.8 -3 .3 -2.4 -!. 4 -1.8 .1 -2.5 .3 2 •. ; 3.1 2.1 . 1 u .6 -" Hllllll >Hlll HHll 1.8 ~ ·' -1 .2 2.1 !.2 .:.o o.7 7 .6 5.8 -1 .6 t'EAN TEMP. ~~G C RES. II HID DT R. DEC 2.2 069 .7 .9 1.5 2.1 1.9 3.8 4.9 3.8 5.2 4.6 5.1 7.6 7 01 6.6 4.9 1.7 3.7 .t •. ~ HHI lUH "*** 5.0 5.7 5.9 5.4 s.a 10.1 12.2 13 ,Q 9.0 5.3 279 :n OM 037 un Oc3 010 332 314 015 063 049 270 },)p 08 4 262 ~7t. 261 )JI HI 29 4 055 2n 254 RES. 4l~D SPD . Ht !J AV G. lll ND SPD . 11/S /l AX. G1JST D!R. DEG 2.7 3.2 08 1 1.1 1.5 3.6 ') 7 • .... .J 2.0 ~.8 1.6 ! . 5 1.6 1.5 2.3 1.8 1.7 1.5 ~.1 ') < -I I.J ') ') ...... 1.8 HU HU 1.1) 1.8 1.9 1.3 1.5 2.6 :.5 1.3 2 .7 .7 2.1> 2 .. ; 1 ! 1.9 ~.0 ') , ....... 2.1 2.Q 2 .1 ? ., -•'- ~ •i 3.7 2 13 2.6 ? . ··" H f f I Hlf Uti 2.3 2.'5 2.9 2.0 1.9 3.4 4.0 3.2 3.0 2.6 262 2!4 070 P.t.7 1;6 000 00 3 316 '!'24 133 109 020 240 330 liH Hll Uf Of!O 099 2Y) 275 08 4 08 5 Q86 OQ2 ~57 27 '5 ~AX . G IJ~T P 't!~L MEA~ "-fA~ SPD . D T ~. FH DP '!'IS ~ DEG C 8 .9 ~NE 5( -6.1 S 7 WSW ). ~ US'4 7 .6 ENF 7 . 0 Nf: 7.6 ~!'if 1 . ~ :m~=: 4,4 N 5 .1 N 8.3 llN~ 6. 3 II 8.3 NNf 7 . 0 li N~ 7 0 ·~ 5 0 7 '41111 0 :s f llf 9 .3 1.1 7 ,6 UN ~ 2 ,? ~ HH liH Hfl H4 **" '** 7, ~ 1.J ?,b N Vi' ~ 10.2 us~ '5.7 (SE 3. 3 II F. o r c • l 10 .2 E 7 ' ') IJ 13.2 tl H H H rc .'.J 54 45 H litH H f H :au !I -3.9 -5 : -5 .3 -2.~ -3 -u -!. 8 t H'H· -5 -3 ~ HJH ~JH't UHf ·UHf -2 .9 -I.:.; UHf -.. : ' ' ,_. '- 6.5 *~** -2 0 0 CU~T VE L . ~T MAX. GU~;T liFL, AT r~AX . r;1 Jt~T VEl . ~ T i'1A X r;u 'n tH;:L , A T nAX. C IJ ST M fN 1.1f.) ? r ~urn MH J 1Jl:) 1 T NTF I~ lJA I ~:; fN I'ER ~)A L I .IJS T P I U'" f N T Ff·'lJAI G IJ ~=; T P L.l.! ~~; 2 I i'.JT F. R t) fH. ·; Pl!ECTP 1'111 0.9 /:..6 ') •'- u n.o u 0.0 ~ ~ o.n ,) . ~ 9.0 0.) 0.0 u ? ... I ? '. ~ HH &'f ¥4 Hfl . ~ .6 u 2.8 u 0.0 o.o n.o ?..b • c ' ...... '- 9. ·:.~ ·~ ,., I ... OAY'5 50i..AR PlfRGY DAY WH/SQII 6705 2233 ':,448 621B ;on c: J 7523 s 7'580 6753 8 '5 12 ~ ? 7320 13 7~33 I I 5755 12 5215 13 509S P 55 00 ! :i 55 25 }.~ 3960 17 4v63 !q ·~~5.3 ~~ HH4!1 20 H<·HH ":! UHU 22 1357 23 b990 ?.t 7223 ~5 4630 2t- 47 0t 27 t-90 5 28 442') ?9 .t b90 ;n 41 13 31 !~73 0 4 ti i)'TT : f~E I A r :•,JF ,11Jt1t r\rf'( 11 1 Anf,'f~!: ,Wf :1~11·1 1 "1 J ttf<l F 1.11:r·N w·:tJn '\l'r··-n•: r~1ll I: '";t) f iiAI'J ONF:~ MI:::T ER t 1 FI< ;;r~C:ON D . ':;1Jf:H IH::':AOI.N f ;!') I·IAVC r-.tr)T BEFN I N f:L_UI)r=:n I.N T HE: DAI I .Y f1P MnNT H I, Ml=-~1 1'• Flir: pr:-1 f:·Trur-H11Mrn r r y A •IT'I n1 ·1.1 rni ''T X ·lh( X· SEF Nil TF~c: A r r I II" r.:t\C I( flf' rt I f.) I<F I ' r)I~T :a·H 1 52 lx & i'-1 C Cl N ~:> U 1... TAN T ~:> , :t: NC. b U ~:> :1: T N A H Y D lx C) E 1. .. E C T lx :t: C P I ~ U :J t::: C T Mul'iTHLf SUMMAR'( FOR DEVIL CANYON WF.:AT HE R S T~TtON !.1 1-1 TA T A kEr~ DU R I 1~G SepteMber . 1982 RES. RES. ~IJG. tiAX . KAX . DAY 'S IIAX . IHN . KEAH \liND WIND \liND GUST GUST p I VAL HEAM tiEAH SOLAR DAY TEMP. TEMP . TBti'. i>IR. SPD . SPD . DIR. SPD . DIR. i!H DP PRECIP ENERGY DAY DEC C DEG C DEG C DEG IVS 11/S DEG 11/S l DEG C riH WH/SQK I 12 .7 4.5 8.o 258 . ~ .9 128 3.2 HHE 4o -3 .2 I . 9 2o78 1 2 II. I 4.3 7.7 Do2 .I !.I tot 3.8 ESE ~9 -2.9 3.4 2358 2 3 8.5 4.9 b.7 093 .3 .7 OOQ 3.2 NH£ 57 -2.2 9.0 to 5i ;) 4 11.2 3.8 7.5 8&9 .3 1.0 157 3.8 ESE 39 -o.o .2 2565 4 5 15 .4 3.1 9.3 09 o 2.4 2.1> 09& 9.5 E 27 -a .o Q,O 2105 5 & 15 .5 7 .I 11.3 040 .& 2. 8 020 8.3 NNE 27 -7.5 u 1&85 & 7 11.7 11.8 9 .3 284 .5 .9 300 4.4 WtlV 44 -2.& 4.o 2118 "! 8 9.2 o.3 7.~ 243 .2 .s 321 2.5 ssw « -3 .8 Q.i 888 8 9 10 .2 4,3 7.3 rn .I .8 291 3.8 SE 54 -1. ~ 7.8 13U 9 10 II. I 3.2 7.2 102 .4 .9 Oo2 2.5 ENE 4o -4 .5 .2 213a 10 11 s.a 2.2 u 07o . 0 .8 297 4.4 sw &2 -2.& 6.4 988 II 12 9.4 -1.4 4.8 107 .b .9 071 4.4 EME 39 -9.4 4.& 2923 12 13 8.9 3 .0 b.& 242 .s .8 2&0 3.2 WSW 57 -.7 31.0 133Q 13 14 8.9 &.4 7.7 \47 .I .& 041 2.5 II bl .9 14.8 IOIQ 14 15 15.5 &.4 11.0 2&& .2 u 341 6.3 IISII 47 -.3 21.8 2391 15 lb 9.i 3.5 b.& 259 1.5 1.9 281 7.& w ~b -7.4 &.8 2583 I& 17 7.2 1.0 4.4 101 .I .9 138 3.2 ESE 72 . I 4.4 1432 17 18 11.1 2.7 &.9 2bl .2 1.0 288 3.2 11511 79 2.9 u 1&28 18 19 8.3 4.3 o.3 158 .2 .7 274 3.2 SE 92 5.4 14.4 775 19 20 7.4 3.9 5.7 070 .I .8 2rr/ 3.8 EiiE 89 3.1 1.4 1213 20 21 11.4 3.2 7.3 188 .3 .9 314 5.1 ESE &7 -I. 7 .6 1285 21 22 o.o -.4 3.1 255 .I I. I 311 4.4 IIHII 78 -2.4 1.2 1530 22 23 8.1 -2 .8 2.7 212 .6 1.0 285 3.8 ssw 47 -10 .2 1.0 2788 23 24 8.& -2 .9 2.9 103 .4 1.1 128 3.2 EliE 75 -1.9 0.0 207~ 24 2S 9.9 -1.1 4.4 203 .2 .9 076 3.2 s 59 -3 .3 Q.O 1825 25 26 &.2 1.8 4.0 158 .I .7 318 3.8 11511 so -7.4 4.2 1120 2b 27 7.3 -1.2 3.1 198 .2 .9 247 3.2 s 2& -16.7 1.8 ISOS 27 28 &.1 -3 .1 1.5 129 .7 .9 1Q9 4.4 ESE 48 -10 .2 5.2 1m 28 29 b.9 1.2 4.1 136 .b .9 112 S.1 Sst 74 1.3 b.b 125Q 29 30 5.5 .b 3.1 321 .2 .7 323 2.5 KHW 47 -&.9 2.2 1190 30 ltOHTH IS.5 -3.1 b.G 139 .1 .7 09o 9.5 ES£ 52 -3.7 ISO.o 51505 GUST VEL . AT MAX . GUST MINUS 2 INTERVALS 5. 1 GUST VEL. AT MAX. GUST MINUS 1 INTERVAL 5.7 GUST VEL. AT MAX. GUS T PLU S INTERVAL 5. 1 GUST VEL . AT MA>.. GUST PLUS 2 INTERVHLS 7.b 1\jO iE : ~E LAT I VE HUMIDITY RE~DINGS ARE UNRELIABLE WHEN WI ND SP EE DS ;.R E LESS TiiA N ONE METER PER S ECOND. SUCH ~ .::ADI 1-I GS HAVE NOT BEE1~ INCLUDED IN THE OHIL r' LlR MONTHLY MEAN FOI< RELATIVE HUMIDITY AND DE W P OINT. AdtA"A· S EE rWTES AT THE BACK OF THIS REPORT ·I( .. Xo ·x-·X· 153 I~ & M C Cl N S U 1 ... T ANT ~:) ;; :J:NC. S l.J S :t: TN A H Y D I~ C) E 1... E C T I~ :t: C P I~ D ,T E C T MON THL Y SU MMARY FOR DEVIL CANYON WEATHER STATION DATA TAKEN DURING Oct o ber, 1 982 ~ RES . RES . AIJG . ItA)(. MX . DAY'S IIAX. IHN. I1EAH WIND WIND WIND CUST CUST p I VAL I'IEAH !'iAN !RA:! DAY TEitP. TEMP. TEMP . DIR. SPD. SPD . DIR. SPD . DIR. RH DP PREC IP EHERGY DAY DEC C DEG C DEG C DEG 1'1/S lt/S DEG 11/S % DEG C HI\ WH/SQII . 1 3.6 ,(, . 2.1 216 0 1 .7 278 2.5 WHW 70 -4.6 lHI 1123 1 2 5.5 -.7 J 2.4 8&9 .3 .8 324 3.8 SE 48 -13.7 "** 1088 2 3 4.7 ~t.5 ; 1.6 113 .6 t.a 117 8.3 HHE 66 -4 .8 HH 1725 3 4 4.1 -4 .2.:' -.1 133 1.0 1.2 117 4.4 SSE &7 -5.3 **** 1855 4 5 3.3 -2.8 ) .3 075 1.3 2.4 030 18 .2 ESE 5& -7.7 HH 1941 5 b 4.5 -&.1 . -.8 14& .9 1.2 02& 4.4 s 58 -8.2 '*** 1790 0 7 .9 -2.9 . -t.e 127 .5 1.1 139 3.8 ESE 48 -14.8 HH 475 7 8 -.5 -4.2. -2 .4 280 .3 t.O 255 4.4 WSW 43 -18.1 IHI 988 a 9 .3 -2.7 ' -1.2 292 ,(, .7 317 2.5 WNW 4 -37.2 HH 375 9 10 -1.3 -5.1 ; -3 .2 388 .9 1.0 323 3.8 HW 71 -11.8 IHf 383 10 11 0.0 -6.3 -3.2 120 .9 1.1 117 5.1 ESE 77 -7.5 IHI 378 11 12 1.8 -1.3 .3 223 .4 .7 314 3.8 sw 23 -25 .1 IHI 395 12 13 -.8 -5.1. -3.1 · 189 .3 .6 343 3.8 s &1 -1 4.7 IIH 428 13 14 -1.3 -9 .2 -5.3 117 1.1 1.1 129 3.2 ESE 78 -7 .2 **** &43 14 IS -3 .1 -13.2 -8.2 109 1.4 1.7 139 4.4 SE 85 -11.8 IIH bBl 15 to -1.8 -8.:) -5.2 103 1.2 1.3 078 3.8 E 82 -7.7 **** ~5 to 17 2.5 ~8 .2 -2.9 137 .6 .9 125 3.2 ssw 2& -29.6 *Ill 478 17 18 .7 -tO.& -5.1 101 .8 1.1 105 3.8 E 55 -17.0 IIlii &38 18 19 -.~ -5.5 -3 .2 058 .& .9 110 2.5 NNE 20 -33.8 IIH 355 19 20 -2.4 -11 .4 -6 .9 117 1.6 1.7 119 5.7 ESE 77 -9.7 IHI 773 20 21 -5.7 -13.3 -9.5 044 1.9 2.7 015 11.4 NNE 65 -14.7 fiH , 928 21 22 -4 .5 -14 .6 -9.6 134 1.3 1.5 116 &.3 ESE 60 -14.8 IHI 889 22 23 -7' 1 -1 2.5 -9 .8 1.'9 2.3 2.4 183 7.0 ESE .'d -1&.2 IIH 755 23 24 -8.0 -13.2 -11.6 189 2.0 2.1 ttl 5.1 ESE 59 -17.0 **** 878 24 25 -7.4 -18.1 -1 2.8 130 1.7 1.8 122 4.4 SE 70 -16.& IIH 788 25 26 -11.3 -19 .4 -15 .4 124 1.4 1.& 100 4.4 ESE 58 -22 .5 **** 720 26 27 -14 .8 -23.4 -19 .t 102 1.& 1.7 102 5.7 E o& -23.4 HH &63 27 28 -11.3 -15.1 -13.2 103 2.0 2.1 184 5. t E 82 -15.8 HH 438 28 29 -7 .4 -19 .2 -13.3 115 .9 1.2 141 4.4 SE 85 -16.2 ***' 631 29 38 -15.3 -22 .9 -19 . t 07& 1.8 1.9 073 4.4 ENE 81 -22.2 IHI 545 30 31 -9 ' 0 -22.7 -15.9 081 2. 0 2.1 06& 4.4 ENE 79 -28 01 HH 585 31 I'IONTH s .s .-23.4 -6.2 104 .9 1.4 015 11.4 ESE os -1 5.7 **** 25252 GUST VEL . AT MA X. GUST MINUS 2 IN TERVALS 9 .5 GUST VEL . AT MAX . GU S T MINUS 1 I NTERVAL 9 "'" ,..,} GUS T VEL. AT MAX. GUST PLUS 1 INTERVA L 10.8 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 11.4 . NOTE: REL ATI VE HUMIDITY READING S ARE UNRELIABLE WHEN WIND SPEEDS AR E LESS THAN ONE ME TE R PER SECO ND. SUCH READINGS HAVE NOT BEEN INCLUDED IN' THE DAILY OR MON:rHLY ME AN FOR RELATIVE HUMIDITY AN D DEW POINT. ·)(-·X ·X· ·X SEE NOTES AT THE BACI< OF THIS REPORT ·)(-·)(-·)(-·)(- 1 54 I ~ & M C UN~:;; U 1... T A NT S _,. :t: NC . S U ~:;; :1: T N A H Y D I~ C) E 1... E C T I~ :t: C P I~ 0 .:r E C T MO NTHLY SU MMARY FO R DEV.:.LL CANYON WEATH ER STATION DA TA TAKEN DURING NoveMber .· 1982 RES . RES. AVG. 111\X . IIAX. DAY'S IIAX . KIM . KEAH WIND wnm 1111111 GUST GUST pI VM. ltEAH KEAH SOLAR DAY mw. TEKP. TEMP . DIR . SPD . SPD. DIR . SPD . DIR . RH DP PRECIP EltERGY DAY 1 DEG C DEG C DEG C DES IVS K/S DEG K/S % DEG C "" lllt/SQII ----- 1 .2 -9.1 -4 .5 121 1.5 1.8 113 7.6 ES£ 73 -7 .5 IHI 653 1 2 -.& -9.6 -5.1 121 .6 .9 185 3.2 s 75 -S.B IHI 615 2 3 -2 .7 -12 .9 -7.8 11& .5 .9 178 3.8 filE 78 -14 .5 IHI «I 3 4 -.3 -5.~ -2.9 125 .9 1.1 178 &.3 ESE 75 -7.2 HH 5b8 4 5 -2.& -H .3 -8.5 135 .& .8 132 2.5 SE 89 -8 .7 IHI 685 5 6 -11.7 -18 .1 -14.9 082 1.6 1.7 182 4.4 88 -16.8 HH 423 & 7 -11.9 -18.5 -15.2 094 2.1 2.3 120 5.1 E iE 80 -18.1 IHI 423 7 8 -7.4 -13.6 -u.s 104 1.7 1.8 098 5.7 E iE 82 -11.3 IHI 348 8 9 '5,7 -8 .5 -7.1 194 .1 .5 120 2.5 11)11 13 -38 .1 till 318 9 18 -5.9 -13.7 -9.8 088 1.6 1.7 175 4.4 EX: 79 -10 .3 IHI 385 10 11 -3.& -6.5 -5 .1 100 1.3 1.4 117 3.8 E!'E 41 -24 .3 IHI 318 11 12 -.5 -&.8 -3.7 131 1.1 1.4 137 4.4 Sl 83 -4.3 fiH 493 12 13 -.7 -6 .5 -3 .& 121 1.1 1.3 11~ 4.4 tS£ 88 -4 .2 IHI 541 13 14 -3.2 -9.2 -&.2 876 .7 .9 189 3.8 EltE 28 -34.8 HH 401 14 15 -&.7 -15 .3 -11.1 193 1.6 1.6 D95 4.4 E 71 -13.1 Hlf 3b5 15 tb -13.0 -1&.8 -14.9 087 2.8 2.0 088 4.4 E 9~ -16.5 HH 351 1b 17 -15.7 -21.4 -18.6 088 2.3 2.4 097 5.1 E 87 -19.9 IHI 351 17 18 -15 .9 -22 .2 -19.1 192 2.2 2.3 898 4.4 E 78 -23.0 I I H 390 18 19 -15 .2 -21.4 -18.3 115 2.8 2.8 115 7.1 ES£ 63 -23 .2 IHI 418 19 20 -111.1 -15.3 -12 .7 115 2.9 3.1 123 &.3 ES£ 79 -15 .4 IHI 330 20 21 -5.8 -10.7 -8.3 093 1.5 1.7 125 4.4 ENE 85 -10.4 Hilt 393 21 22 -4 .6 -7 .5 -&.1 103 l.b 1.8 119 ~.1 EME 80 -8.9 Hlf 378 22 23 -.8 -b .O -3 .4 112 1.1 1.3 113 3.8 ESE 84 -4 .4 IHI 348 23 24 -I.Q -4.7 -2.9 13b 1.4 1.4 138 3.8 SE 91 -3 .4 II II 335 24 25 .s -&.7 -3.1 138 1.4 1.5 1 ~9 3.8 SE 79 -5.2 IHI 358 25 2& -4 .9 -7 .3 -6 .1 11& 2.4 2.4 119 5.7 ESE 76 -9.7 IHI 358 2& 27 -3 .8 -11 .8 -7.8 88b 1.5 1.6 11 4 4.4 E 88 -8.5 Hfl 3b3 27 28 -11.3 -14.7 -12 .5 988 2.7 2.7 070 4.4 E 95 -13 .8 IIH 308 28 29 -5.4 -10 .1 -7.8 897 1.1 1.2 131 3.8 EH£ 31 -15.5 IHI 258 29 30 -5 .8 -12 .0 -8.9 259 .4 .7 276 3.8 w b9 -12.2 Hff 273 30 ltOIITH .5 -22 .2 -8 .9 104 1.4 l.b 113 7.6 ESE n -tl.b **** 12060 GUST VEL . AT MA X. GUST MINUS 2 INTE RV ALS 5. 1 GUST VEL. AT MA X. GUST MINUS 1 INTERVAL 5 .7 GU ST t)EL. AT MAX. GUS T PL US 1 INTERVAL 5.7 GUST VEL . AT MA X. GUST PLUS 2 INT ER VAL S 3 .8 NOTE: RELA T IV E HUMIDITY READINGS ARE UNRELIA BLE WHE N WI ND SPEEDS ARE:. LESS THAN ONE MET ER PER SECO ND. SUCH READINGS HAVE NOT BE EN INCLUDED IN THE DAIL Y OR MONTHLY MEA N FOR REL AT IVE HUM I DITY AND DEW POINT. -~·)(-·~'.(· SEE NOTES AT THE BACK J F THIS RE PORT ·)(-·lf<*·~ 1 55 1 l x &. M C D N ~:> U L T AN T ~:> > :t:NC. ~:> U ~:> :t: T N A H Y D lx D E 1... E C T l x :t: C P lx U ,T E C T MO NTHL Y SUM MAP.Y FOR DEV IL CANYON WEATHER STATIO N DATA TAKEN DURING Dec eMber 1 1982 ( MAX. ~IN. MEAN DAY TE!f . TO'JI. TEI1P . DEC C DEC C DEC C RES. WIND DIR. DEC RES . WIND SPD. ~/S AVG . WIND SPD. ~/S MAX. GUST DIR . DEC ~AX. GUST P'VAL 11EAN SPD . DIR . RH ~IS % tt£AN DP PRECIP DE:G C !ill DAY'S S!l.AR OIERCY Di\Y WH/SQ" ----------- 1 -11.1 2 -15.1 3 -It. 9 4 -13.1 5 -4 .7 b -l.S 7 1.8 8 0.0 9 -.b 10 -4 .3 11 -4.8 12 -2.3 13 -.1 14 -. 9 15 .3 lb -.3 17 -2.6 18 -11.2 19 -b .b 20 -5.6 21 -15.4 22 -16 .0 23 -11.8 24 -8.0 -19 .9 -21.6 -2 1.4 -18.7 -13.1 -7.5 -1.9 -1.8 -14 .4 -19 .I -8.7 -6.9 -5.1 -9.0 -5 .5 -5.0 -19.5 -13.9 -13.8 -15 .3 -18.9 -20.6 -17.8 -16 .8 25 -7 .8 -1?..7 26 -.8 " .4 28 .9 29 1. 7 :!0 -.1 31 -b .b 11CHTH 1.9 -8.7 -2.9 -.4 -.3 -9.3 -10 .4 -21.6 GU ST GUST GUST GUST -15.5 117 -18.4 121 -16 .7 107 -15.9 108 -9.9 tea -4.5 122 -.1 107 -.9 . 134 -7.5 067 -11.7 110 -6.8 129 -4.6 130 -2 .6 145 -5. I 142 -2 .6 130 -2.7 134 -6.6 107 -12.1 089 -9.8 113 -u.s 124 -16.9 083 -18.3 075 -14.8 099 -12.4 105 -10.3 102 -4.8 130 .. o.J 1.5 1.2 2.3 1.3 1.7 2.3 .7 1.0 t.b ?.. 0 1.5 1.3 1.1 1.5 1.4 1.8 1.7 1.1 l.b 2.6 2.6 1.8 2.3 2.1 1.2 .8 280 1.7 133 1.6 !25 2.5 125 1.3 098 1.9 110 2. 4 107 1. 0 305 I. 7 277 1.9 141 2.1 108 1.6 124 1. 5 109 1.2 124 1.7 182 t.S tiS 1.9 117 1.8 on 1.3 122 1.8 123 2.6 071 2. 7 072 2.0 101 2.5 119 2.3 lib 1.4 101 -1.3 143 .3 145 .7 179 .8 .3 .b 1.0 098 .4 097 1.0 252 -4.7 *** Ufl un 1.4 -8.5 Ul -8.2 111 1JEL, AT VEL. AT VEL. AT VEL . AT MAX . MA X. MAX. MAX. nn n• flU fll 1. 7 107 GUST GUST GUST GUST MI NUS MI NU S PLUS P LUS 3.2 SE 92 -17.7 ***• 5.1 SE 96 -20.1 tltt 4.4 ESE 80 -18 .9 1111 6.3 ESE 75 -20.5 lt!t 4.4 E:SE 83 -10.3 ***' 7.0 sE en -7 .9 •*** 9.5 ESE 81 -2.7 tltt 5.1 SE 11 -36.5 '*** 5.1 ENE 93 -9.1 ttlt 6.3 ESE 96 -13.3 **** 6.3 ESE 77 -IC.1 **** 5.1 ESE 71 -7.2 !*II b.3 SSE 83 -5.0 *"* 4.4 SE 93 ·6.9 tl!t 5.7 ESE 73 -b . 1 nu 4.4 SE 74 -6.7 **** 4.4 ESE 92 -7.5 l tlt 4.4 E: 78 -13.0 4111 4.4 SE 86 -12 .3 *'*' 5.1 ESE 74 -13.5 Ill! 5.1 E 91 -17.7 *•** 5.7 ENE 87 -28 .5 **** 4.4 ESE 75 -18.1 ~ttt 5.7 ESE 90 -14.6 tt!t 6.3 ESE 81 -13.5 t t t t 4.4 ESE 80 -9.4 lttt 3.2 SSE 70 -9 .0 1111 1.9 SE 10 -28.4 l tll 3.2 SE 11 -27 .J ~**' 1111 1*1 5 -37.6 I ll! If. II HI \ -46, 0 HI!! 9.5 E:SE b9 -15.7 tttt 2 INT!::R W'I LS INTE R1 .. 1AL 1 INTERVAL 2 INTERVALS 7.0 6.3 0 c:- 0 • -.) 8.9 268 283 2 293 343 4 305 5 333 6 301 7 258 8 271 9 273 19 295 11 310 12 328 13 318 14 308 15 315 16 303 17 308 18 301 19 315 29 311 21 305 22 328 23 308 24 318 25 300 26 253 27 240 28 268 29 253 3C 251 31 914 3 NOTE: RELn TI VE HUMID1TY READINGS ARE UNRELIABLE WH EN WI ND SPEEDS ARE LESS THAN ONE MET ER PER SE COND . SUCH READINGS HAVE NO T BEE N INCLUDED I N THE DAI LY OR MON THLY ME AN FOR RELATIVE HUMIDITY AND DEW POI NT. **** SEE NO TES AT THE BAC K OF THIS REPORT **** 156 MONII-t l Y SU MMAK:Y FOR DE \~L CAN f OI'I wEATHER SI Afi ON DATA lAKEr! D~RI~G J anu ar~: 1 9 83 DAY liD. ID\~. DEG C 1 -1. i 2 -1.4 3 -4.2 4 -I !.3 5 -1 7.9 6 -lid ; -17.2 8 -22 .4 9 -23 .2 10 -2 0.2 11 -Hi.2 12 tfifl 13 IHH \4 Uht IS tun lo HUt 17 UUt 18 ..... 19 -5 .8 26 -5.5 21 -4 .4 2.2 -B.8 23 1.11 24 -3 .8 25 -S.B 2b -1 .9 27 -5.5 28 -3.9 2~ -~.4 30 -4 . u 31 i. 9 nGttin 1. 9 tllti. TEIIP. DEG C -7 .2 -4 .2 -11.7 -21.0 -24 .9 -21.1 -25 .4 -27.0 -26 .4 -2b.2 -31.11 ***** tHU tiUt dUt Ullf Uiiltf lflfl -7 .4 -12.3 -1 1.3 -18. ~ -i5.u -9.9 -9.9 -7.3 -l&.b -12 .2 -13.Y -9 .7 -5.3 -31 .o nEAH TEIV. DEG C -4 .2 -2.8 -8 .1 -16.2 -21.4 -18 .7 -21 .3 -24.7 -24.8 -23.2 -24 .9 tfltl nut dill tllll 11iH* tltli IIIII -b .b -9 .1 -7.9 -13.4 -6.7 -b.9 -7.9 -4.6 -8 .1 -8.1 -9.7 -b.9 -1.7 -12.0 RES. <liND Dix. DEG ttl 11 4 115 097 102 112 110 124 133 123 115 11H H:t ... tit ... !ttl ffl 102 119 128 084 12u 108 164 115 u99 109 u9i !21 137 112 ~ES . wiHD SrD. n/S uu 2.1 .9 1.3 1.5 2.4 2.5 1.2 2.3 2.2 1.7 .... tilt ttli .... **** .... 11111 .b 1.5 l.b 2.b 2.3 2.3 2.2 1.8 2.2 1.9 2. i 1.7 1.1 1.8 AVG. Iii liD SPD. IllS 11111 2.1 1.0 l.S 1.7 2.5 2.& 1.5 2.4 2.3 2.0 IHI Utlt 11111 lUI **** .... .... .9 l.b !.7 2.6 2.7 2.b 2.3 2.0 2.6 2.1 2.3 1.9 1.3 1.5 IIAX . GUST DIR. liEG ... 191 107 092 092 lOb 094 088 109 121 140 IH Ill fit til *** Ut ... 274 111 124 ~89 131 10 0 102 123 113 137 124 104 115 100 I'.AX. GUST pI VAL riEAri r!EAI'I S?O. OIR . RH DP PRECIP n/S 4 uEG C ~M .... tit 5.1 ESE 4.4 ES£ 4.4 ENE 4.4 E 8.9 ESE 8 . 9 ESE 5.1 ESE 5.7 SE 5 .7 SE &.3 E ....... flit tH .... Ill lUI Ut 1111 Ill tlttt !ttl uu ... 2.5 SE 5 .I ESE 4.4 SE 7. 0 E 8.3 Est 9.5 ESE 8.3 ESE 7.& ESE o. 3 EN£ 4.4 ESE 5.1 t: &.3 ESE 4.4 SE 9.5 ESE 82 . -'4 .8 lUI 78 -8.9 llil 71 -11.4 ltfl 67 -18 .& 1111 79 -25.0 .... 67 -22.5 lilt b7 -25.4 an 110 -29.1 .... 57 -30.4 .... 52 -29.7 filii b8 -32.1 •••• u Iiiii 1111 It lltltt Hll u tHtt un u ltllt "*' II IIIII 1111 -~ •titt 1*11 111 111111 flit 50 -lb.S ttlt 82 -10 .1 fill 54 -14 .4 f ttt 63 -19.?. 1111 37 -1 l •••• 33 -20.5 •••• o\2 -18.8 **** 59 -1 1.3 lflt 74 -12.3 •••• b1 -10.5 •••• Bi -1 1.8 t.tt• 62 -8.7 •••• 73 -4 .9 till 65 -17.3 111*11 ~USI VEL. AT MAX. GUST MIN US GUST vEL. AI MAX. G~SI MINUS GUST VEL. AT MAA. GUST PLUS GU ST VEL. AI MAX . GUST PLUS 2 INTERVALS 1 HH ERVAL 1 INTERV AL 2 I NTERVALS 7.6 8 .9 7.0 5 . 1 DAY 'S SOLAR ENt:~GY OAf llntSQn 205 2&8 253 278 278 290 34i 2 3 4 b 363 8 3113 9 365 10 311 11 ilttiU 12 HUfl \3 ...... 14 1111-tit 15 UHII to HUU 17 t UUI 18 269 19 358 21i 128 2! 418 22 5ijj 23 663 24 55Q 25 503 2& m 27 530 28 4·iu 29 533 3u 573 3! 9i35 ... ] ~8 f E: ~E i~TI V E ri~MIDIIY READINGS ARE UNREL IABLE WH EN ~IND SPEEDS A~E LESS Th~ ONE hEIER PER S ECOND . S UCH REA DI NG S HAVE NOT BEEN INCLUDED IN THE DA I L' uR riO~THLY MEA!'! FOR RE LATIVE NUMIDITY AND DEW POINT. lk•* 5E E NOTES AT ThE BACK OF THIS REPORT •••• 157 I~ ~ M C 0 N ~:; l.J 1... T A N T S > :J:NC. MONTHLY SUM MARY FO R DEVIL CANYON WEATHER STATION DATA TAKEN DURING February , 1983 RES. RES. AIJG. MX. MX. DAY 'S KAX. KIN . l£M wnm WIND WIND GUST GUST p I Vlt. HEAII t£Ait SOl.AI DAY T£liP . TEJIP . rnw. DIR . SPD. SPD. DIR . SPD . DIR. RH DP PRECIP EJDGY DAY lEG c DEC C DEbC *' IVS lt/S DEC IVS % DEC C "" Iii/Sill 1 3.3 -1.5 .9 133 1.6 1.7 112 5.7 ESE 67 -4.4 "** 595 1 2 1.5 -2.9 -.7 138 1.4 1.6 142 4.4 SE 78 -3.? HH &tl 2 3 .3 -3 .2 -t.S 135 1.5 1.6 115 7.1 ESE 73 -5.3 "** 615 3 4 1.1 -4.8 -1.5 i23 1.7 1.8 199 6.3 SE 69 -6.2 HH b20 4 5 1.1 -6.7 -2.8 119 1.8 2.1 195 7.6 ESE 64 -7 .3 "** 703 5 & 1.3 -9.4 -4 .1 145 .7 1.2 098 5.7 SSE 79 -5.2 HH ~ & 7 -2 .4 -7.5 -5.1 251 .3 .8 314 3.8 IISW 38 -22.6 "** 495 7 8 -3.8 -12.8 -8.3 122 .2 .6 193 3.8 ESE 50 -14.4 HH 448 8 9 -8 .9 -18 .5 -13.7 117 1.1 1.2 113 4.4 ESE 94 -16.2 **** 43.'\ 9 II -8 .4 -21 .1 -14.2 121 .8 1.1 12o 5.1 E 90 -1&.1 HH 58·1 11 11 -18.9 -21 .2 -15.6 191 1.8 1.9 117 4.4 E 84 -18.7 *"* 46S 11 12 -11.9 -22.8 -17.4 189 1.7 1.8 182 5.1 E 83 -21 .5 HH 558 12 13 -i+rS.. -24 .2 -19.4 887 2.1 2.4 116 5.1 El£ 78 -22.2 HH 583 13 14 -12.5 -19.8 -15.8 168 1.5 1.7 158 4.4 EJ£ 74 -19 .8 HH 721 14 15 -5.8 -19.3 -12.6 113 1.9 2.1 123 5.1 ESE 61 -19.2 HH 815 15 16 -6.2 -13.7 -11.1 115 2.3 2.4 199 5.1 ESE 47 -21.8 HH 843 16 17 -7.4 -15.1 -11.3 128 2.5 2.& 128 6.3 SE 45 -21.9 **** 898 17 18 -8.5 -14.7 -tt.6 liB 2.1 2.2 191 6.3 ESE 68 -to.8 HH &28 18 19 -2 .2 -13.1 -7.6 118 1.& 1.7 113 4.4 ESE n -9.6 HH 743 19 28 -1.6 -13.2 -7 .4 115 1.5 1.1 889 5.7 SE 71 -11 .1 HH 1883 28 21 .1 -9 .6 -4.8 195 1.5 1.6 196 5.1 E 67 -9.3 HH 1141 21 22 3.1 -11 .7 -3.8 126 1.4 1.7 114 5.1 SSE n -8.2 **** 1085 22 23 1.7 -8.8 -3.6 121 1.7 1.9 198 7.1 ESE 58 -18.1 **** 1158 23 24 -.8 -7.3 -4.1 109 1.9 1.9 088 5.1 ESE 78 -5.9 HH 9~~ 24 25 h.!}--12 .7 -5.5 122 1.2 1.6 893 7.6 E 47 -16.5 HH 1388. 25 26 .5 -4 .9 -2.2 125 1.7 1.8 111 6.3 ESE 67 -8.3 HH 13bl 26 ZJ 1.1 -9.8 -4.4 117 1.5 1.7 118 5.1 ESE &6 -u.a HH 1598 27 28 -1.1 -7 .1 -4. t 178 1.1 1.3 119 5.1 HE 58 -15.7 **** 1288 28 IIOHTH 3.3 -24.2 -7.5 112 1.4 1.7 895 7.6 ESE &9 -13.8 **** 22418 GUST VEL. AT MAX. GUST MINUS 2 I NTERVALS 3.8 GUST VEL. AT MAX . GUST MINU S 1 INTERVAL 6 .3 GUST VEL . AT MAX. GUST PLU S 1 INTERVAL 6.3 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 5 .7 NOT E: RELATIVE HUM I DITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LE SS TH AN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DA IL Y OR MONTHLY MEAN FOR RELATIVE HUMIDiTY AND DEW POINT . ·lfo ·)(o~·~· SEE NOTES AT THE BACK OF THIS REPORT ·iHHt·-)(o 158 lx ~ M C C) N S U L. T ANT ~:> > S US :J: TN A H Y D I~ 0 E L. E C T I~ :t: C P I~ D S E C T MONTHLY SUMMARY FOR DEVIL CANYON WEATHER STATI ON DATA TAKEN DURING Mar·ch 1 1983 RES. RES. AVG. IIAX. IIAX. DAl 'S KAX. 111M . I£AH III MD IIIND WIND CUCT GUST P ' Vrt. 11EAN I(AN WR DAY TElf. TEll'. TEIW . DIR. SPD. SPD. DIR . SPD. DIR . RH DP PRECIP ENERGY DAY DEGC DEG C DEG C DEG 11/S 11/S DEG 11/S % DEG C ttll WHISQ!t 1 -2.1 -6 .7 -4.4 156 .5 .7 869 2.5 liE 41 -23.3 IHI 813 1 2 -4 .4 -14 .1 -9.3 113. 1.9 2.0 113 5.7 ESE 71 -11 .9 **** 1605 2 3 -8.1 -16 .5 -12.3 188 2.6 2.S 110 7. D E 77 -15.8 IHI 162!1 3 4 -9.0 -16 .7 -12.9 108 2.6 2.9 097 7. 0 E 77 -15.3 **** t27S 4 5 ~.4 -12.1 -8 .3 199 2.2 2.3 121 5.1 ESE 72 -12 .2 *'*' 1893 5 0 -.8 -13 .5 -7.2 194 1.8 2.0 096 5.7 E 69 -12 .1 Hfl 1765 6 1 -1.0 -10.7 -5 .9 096 1.7 2.8 131 5.7 ENE 67 -12 .2 IHI 1828 7 8 . 1 -14.3 -1.1 987 2.1 2.3 984 5.1 EHE 58 -15 .6 **** 2069 a 9 -2.2 -17 .1 -9.1 086 2.3 2.S 898 6.3 ENE 55 -18 .3 ***' 2095 9 10 -6.4 -16.3 -11.4 089 1.7 1.8 105 5.1 EM£ 88 -12.6 IHI tl81 18 tt 1.5 -7 .3 -2 .9 113 1.6 1.8 192 5.7 ESE 88 -6.7 HH 1625 11 12 6.4 -1 .9 -.8 ua 1.1 1.3 130 5.1 E 74 -6.9 **** 1658 12 13 5.1 -9.2 -2.1 089 1.6 1.9 lOb 5.1 ENE 67 -8.3 **** 23711 13 14 2.6 -7 .8 -2.6 894 1..6 1.7 974 5.1 E 67 -7.5 **** 2088 14 15 3.4 -5.1 -.9 195 1.5 1.7 899 5.7 E 71 -5 .9 IIH 2123 15 to 3.5 -8.5 -2 .5 198 1.7 1.9 097 5.7 ESE 69 -7.4 **** 2675 16 17 2.8 -11.8 -4.5 111 1.1 1.4 196 4.4 ESE 67 -8.4 IHI 28711 17 18 2.6 -11.9 -4.7 111 1.6 1.9 114 5.1 E 75 -9.5 **** 2783 18 19 2.1 -13.4 -5.7 087 1.9 2.0 872 5.1 E 71 -11.7 IHI 2871 19 20 1.4 -7.8 -2.8 190 1.9 1.9 084 6.3 E ~; -8.9 **** 2913 20 21 2.7 -7 .5 -2.4 095 1.6 1.7 804 S.l E 56 -11.2 **** 3855 21 22 3.2 -18.6 -3.7 193 1.7 1.9 186 5.7 E 59 -11.2 **** 3050 22 23 1.3 -11.2 -5.0 188 1.7 1.9 875 5.1 E 59 -11.9 IIH 3108 23 24 .7 -11.0 -4 .7 086 L6 1.8 061 5.1 E 64 -9 .9 **** 2575 24 2S 2.2 -6.0 -1.9 130 1.4 1.6 117 5.7 ESE 59 -9.3 ***' 32SI 25 26 1.8 -5.7 -2 .8 115 2.1 2.4 892 8.3 ESE 54 -18.3 **** 3133 26 27 .5 -7.1 -3.3 117 2.1 2.3 108 7.8 ESE 52 -12.0 HH 3325 27 28 2.6 -8.0 -2 .7 107 1.7 1.8 068 5.7 ESE 55 -11.8 HH 3455 28 29 3.3 -11.5 -4.1 094 2.0 2.1 108 6.3 E 67 -9.9 IIH 3568 29 30 3.4 -1 t.8 -3.8 104 1.7 2.8 100 5.7 SE 65 -9.8 **** 3688 30 31 5.3 -7 .4 -1.1 102 1.6 1.9 183 s. 1 E 68 -&.6 ***' 32711 31 110NTH 6.4 -17.1 -4.9 899 1.7 1.9 892 8.3 E 00 -11.0 **** 74842 GU S T VEL. AT MA X. GUST MINUS 2 INTERVALS 5. 1 GUST VEL . AT MA X. GUST MINUS 1 TNTERVAL 6.3 GUST VEL. AT MAX . GUST PLUS 1 INTERVAL 7 .0 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 7.6 NOTE: RELATIVE HUMID ITY READINGS ARE UNRELIABLE WHEN WI ND SPEED S ARE LESS THAN ONE METER PER SECOND. SUCH READINGS HAVE NOT BEEN IN CLUDED IN THE DAILY OR MONTHLY MEAN FOR RELATIVE HUMIDITY AND DEW POINT. *·X·'JC··~ SEE NOTES AT THE BACK OF THIS REPORT **** 1 59 I~ & l'-1 CON S ULT A N T S ,. J: N C . MONTH LY SUMM ARY F OR DEV IL CA NY ON WEA THE R S TATION DATA TAKEN DURI NG Apr il .· 1983 RES . RES . AVG . MX . MX. DAY'S MAX. IHit ItEAM wnm WIND WIND GUST GUST P 'VAL HEAH ltEAH SOLM DAY IDIP . mtP . TOIP . DIR . SPD . SPD . DIR . SPD . DIR . RH DP PRECIP ENERGY DAY DE&C DE& C DE& C DE& IVS lt/S DEG IVS 1 DEG C "" WK/SOK I 5.9 -9 .1 -l.b 183 1.7 2.0 113 5.7 SE 71 -&.5 o.o 3718 I 2 o.7 -9.2 -1.3 081 1.7 2.1 870 &.3 EHE &4 -8.0 ••• 39&3 2 3 5.1 -9.0 -1.5 113 1.9 2.2 109 &.3 ESE 62 -7 .3 1.0 4168 3 4 4.6 -2 .5 1.1 123 !.3 2.5 281 10 .2 ESE &8 -4 .6 ••• 1&90 4 s 1.& -3 .1 -.8 084 .8 1.2 196 3.8 E 71 -8.1 .2 2505 5 & 3.5 -5.4 -1.8 128 1.1 1.6 127 5.1 SE 52 -14 .8 .2 4010 6 7 3.6 -5.4 -.9 12'. 1.4 1.8 110 4.4 ESE 67 -7.3 8. Q 4048 7 8 2.6 -5.9 -1.7 352 .5 1.4 328 4.4 1£ 69 -7 .6 8.1 2923 8 9 .5 -11 .8 -5.2 384 .4 1.3 323 5.1 NW 67 -11.7 .2 2888 9 to -1.2 -12 .3 -6.8 075 1.1 1.7 Ill 6.3 ESE :lo -12.7 1.1 4413 10 11 -4.5 -12 .3 -8.4 09& 1.2 t.S 161 b.3 E b8 -13 .3 1.0 2380 11 12 3.4 -5 .9 -1.3 188 .6 1.0 162 4.4 ESE 50 -14.4 3.4 2445 12 13 3.8 -3 .1 .4 105 .9 1.2 102 4.4 ESE 54 -12.5 4.0 3228 13 14 4.4 -2 .3 1.1 338 .s 1.4 329 b.3 IN so -14.0 .a 3470 14 15 3.4 -1.3 1.1 i 27 .4 .7 oos 3.2 N 29 -22.4 6.0 1971 15 16 5.1 -1.8 1.7 en .7 1.2 129 7.6 liME 58 -7 .8 3.2 31GB 16 17 4.b -5 .2 -.3 115 . 0 t.S 251 5.7 " 62 -8 .7 •. 0 lbbl 17 18 5.0 -2 .7 1.2 873 .9 1.3 854 7.1 ESE &7 -3 .& &.2 3.018 18 19 &.1 -1.7 2.2 103 .2 l.b 097 7.8 ES£ b1 -6.3 1.0 4625 19 20 6.8 -3 .1 1.9 097 1.2 l.b 054 7.6 E b3 -4.7 0.1 4503 28 21 7.& -3.3 c.2 894 1.4 1.7 108 5.1 ESE 59 -6.7 •. 0 5301 21 22 7.2 -.6 3.3 282 .3 1.2 287 3.8 IIHW 73 -3 .4 .4 3653 22 23 4.3 0.0 2.2 386 .4 .9 323 4.4 WHII 17 -27.5 3.0 2&81 23 24 12.1 .9 6.5 083 .5 1.3 047 5.7 EME so -4 .3 1 .0 5655 24 25 14.3 .. .J 7.4 152 .7 1.4 099 5.7 s 52 -1.1 0. I ~ 25 26 12.2 -l.b 5.3 245 .4 t.t 317 3.8 SSE 62 -2 .8 1.1 5618 26 27 11.1 -2 .3 4.4 175 .2 1.3 188 5.1 E 57 -4.2 1.0 5788 27 28 9.4 -1.4 4.0 358 .6 1.4 323 5.1 EHE 59 -8 .3 0.0 3845 28 29 6.9 .6 3.8 271 .3 .7 118 3.2 s 56 -18.11 . s.o 2918 29 30 \8 .5 -1.6 4.5 834 1.3 1.8 121 6.3 liME 41 -7.4 1.0 6235 30 IIONTH 14.3 -1 2.3 .8 091 .6 l.S 281 18 .2 ESE 59 -9.0 33.2 11382 1 GU S T VEL . AT MA X. GUST MI NU S 2 INTE RVA LS 5.7 GUST VEL. AT MAX. GUST MIN US 1 IN TERVA L 5 . 1 GUST VEL . AT M ~. GUST PLU S 1 INTERV AL 8.9 GUST VEL . AT MAX . GUST P LUS 2 INT ERV ALS 7.6 NO T!:.: RELAT I VE HUMIDITY REA DINGS ARE UNRELI ABL E WHE N WIND SPEED S ARE LE3 S THA N ONE METE R PER SECOND. SUCH READI NGS HAVE NOT BEEN INCL UD ED IN TH E DA I LY OR MO NTH LY MEA N FOR RELATIVE HUMIDIT Y AND DEW PO I NT. ·)(-·X·~·X· S EE NOTES AT TH E BACK OF THIS REPORT ·X"~** 160 r~ .'\c M C D N S U 1... T A N T ~;~ , T ~··I('~ . ~:> U ~:~ :1: T N A H Y D F~ 0 E 1... E C T F~ :t: C P t=.:: fJ .. ·.r F C T MONTHLY S UMMAR Y FOR nEVIL CANY ON WFATH FR S TATtON DATA TAKEN DURr~G M~u 1 983 NIJfF: ·'11<·1\'·X··X· DAY MAX. Tfl!P. CEG C IHN. T81P . DEG C !lEAN TEMP. DEG C PES . WIND DI R. DE G ~ES . ~IND SPD . 11 /S AVG . \11~1) SPD . 11/S 11AX. GU'>T DIR. DEG ~AX. GUST P'VAL MEAN SPD. DTR. RH 11/S 4 I£ A~ DP Pl1fCIP l)EG C r!K nAY'S SOLAR ENERGY DAY IJH/S911 -----·--·---------------'-·-----·-----·------------------·--·--·------ 1 1 I. 0 2 5 .1 3 4,9 4 7.7 5 9,4 6 9.7 7 t 1.3 8 13 .5 9 I!. 9 10 t 1.1 It 12 .8 12 to. 7 13 !3.2 14 12 .9 15 13.7 16 12.7 17 8.1 18 8.6 19 11.4 20 !4.5 21 ! 0. 7 22 11.3 23 10 .s 2.! 12, ~ 25 15.4 26 12.7 27 12 .7 2B :6.3 29 20 .1 30 1 Q. 7 31 11.9 140NTH 29 .1 -2.2 .3 -'] -.8 -.B -1.5 -2' 1 -.3 0.0 1.5 2.5 4.5 4 , t 2.2 .3 2.6 2.6 1.2 4.3 4.3 3.8 3. 0 .9 -,0 '] '] ....... 1.1 3.~ 5.1 P..S 6.5 -2.2 4.4 083 2.7 30 ~ 2.4 305 3.5 ~bb 4.3 oao 4 ,1 0'57 4. b 035 6.4 185 6.0 276 6.3 236 '5.8 219 6.6 076 8.9 291 8 .5 26 1 e. o 212 6.5 070 5.4 326 5 .6 283 ~.3 2~6 9.4 2?9 7.5 29 ~ 7.6 322 6.8 286 6.7 077 7.3 29 4 7.5 316 6.9 049 9.9 63 6 12 .6 99 4 14' t 105 9,2 2'5 1 6.8 00 4 .B .5 4 1.3 .6 1.4 1.4 .4 ., '"' .6 ,4 1.0 .2 .6 .b .4 .2 .5 .3 1.4 1.5 .6 .2 1.2 1.0 .6 .b .4 1.1 .3 .3 .2 1.5 091 .1 cS 8 .? 315 1. 7 023 1. b 089 2.0 020 1. 9 011, 1.5 2?7 1.3 31 ~ 1.1 273 1.3 307 1.6 127 1.2 286 1. 2 303 1.2 300 1.3 056 1.3 325 1.4 320 1. 4 ~~5 1. 9 309 1. 7 330 1.2 325 1.1 013 1. 8 084 1.7 296 1.4 295 1.4 002 1.6 1;10 1.6 OBS 1. 5 095 1. 0 252 t. 4 0?5 5.1 ENE 3.8 Nil 3.8 ~HW 6.3 ENE 0.3 ssw 7.6 ti~E 6.3 NNE 4.4 s 5.7 ssw 5.7 liSW 4.4 ssw 1. 8 IINF. 3.8 !-~Nil 4. 4 s 5.1 WNW b.3 f 5.1 NW 5.7 )lY ~.7 tSE 7. 0 ~~~ 6.3 1111 5.7 NW 5.1 sw 70 67 )6 67 59 5B /:,3 49 50 59 61 61 ~6 42 3i! 66 c-o .•..: 59 ?! n 71 o.3 ENE 59 7.6 WNW b3 6.3 WNII .~.3 [');: 5.7 s 7.0 ENE 3.9 LISW 4.4 i.JN\1 8.9 ~NW 31 70 ... ~J 57 65 90 62 -4.4 -18 ./ -3 .4 -3 .3 -4 .2 -1.4 -2 .2 -I. 4 -.1 -2.5 -2 .1 .. ) 2.1 3.5 'l -7 .9 -\7 .9 -1 .9 .b .9 l.tl -.7 1.? 3.8 3.0 4.8 '] •'- 6.6 ~.2 0.0 Q.O u u 0.0 n.o 0.0 n.o 0.0 3. 0 1).0 u '] ·) .... ~ "' . .: '~ 1). 0 0.3 1.4 1.2 'l .... '] ... 0. ~ n.o 6.6 . u 9.2 o.o 7,5 u -1 .2 25 .4 GlJ S T VF.L. AT MA X. GUST MTNU S 2 INTFI~\JA I S GUS T I.Jr.::L. AT MA"x. GU!=)T 11 Il\JI)S 1 f.NTEF?UAL a::' '7 _, . ' c ...., •. J., Gli S T UE.L. AT t'~r~X . GUST Pl. US 1 Ii\ITF R'J AI GUST 'WL. AT MAX. GUST PL U!1 2 rNTER \JA LS ,~-,I 3 ""') 1'7 l_. I .J i(ELAfl'JE H UMT JYJ:TY RF.ADINGS ARE UNRFLIABI E ,,J IW N I,.ITNT) Sr 'FI?'n.r~ ONE Mr.::TER PER SFCO ND . S UCH READ I NG S HAVE NOT BEEN IN CLUDED OR MONTHLY MEA N FOR RE LATIVE HUM IDITY A~D DF W POIN T. S E C NOT[S AT THF BACK OF THIS REPORT **** 161 5318 2308 2 1499 1 4658 4 4'i91 s 5:23 I, /)~2B : 6590 8 '}373 ? .:,m ~~ 612e 11 4b88 12 4571 11 44b0 I d .~~ao 15 3°93 ! 6 2798 17 ~253 !!?. "i0 4Q • c;· 6095 2 ~ 3125 :· .1111 2~ 4000 23 5280 2.1 1815 25 400 8 26 432'3 27 5090 29 ~790 ~9 3503 ~0 2165 "3 1 !43590 ~11~F 1 .1·· ~~~ THA IN THF~ I)AII ... Y J I I I ] T i'.! C . ~:; U ~:; :I: T N ,·~ H Y D 1:.:.: D E 1... C C T I ~ :1: C P H C) :.r L : C ·-r il o ' i " f I ' ~ :-I D u R I r! c s...: p t !? M ::J e '; DAY ., .. 3 4 5 b 7 8 9 10 11 12 13 14 IS 16 li 18 19 20 21 .,., ...... 23 24 25 26 27 28 29 30 IIDNTH 11'-X . T~P . DEG C lc.o 14.7 11.5 13.8 16 .7 15.3 H .3 11.9 12.9 12.6 7.9 11.9 8.7 IU 17 .0 12.1 8.2 12 . a 9.4 9.5 10.0 !U 11.8 9.9 11.1 8.1 9.9 7.3 9.4 7.2 17 .0 ~IN. T8iP . DEG C -0 ~ .. 3.7 5 . 0 1.8 3.1 5.2 7 .5 &.4 5 .& 4.8 -.6 -.4 4.4 7.1 7.3 5. 0 2.5 3.7 b.O .. .. .J,,J 5.1 -.9 -3 .3 -5 .1 -3 .0 2.2 -1.4 -3.0 2.& ') .. ... ,J -5.1 IIEAN TOO . DEG C 10.3 9 .2 8.3 7 .8 9 .9 10.3 10.9 9.2 9.3 9.7 3.7 5.7 b.& 8.9 12.2 8.6 5.4 7.9 7.7 7.5 7.e 4.7 4.3 2.4 4.i 4.3 ., ., ....... u 4. 9 7.1 RES. lli ND DIR . DEG 045 223 043 202 050 186 214 208 202 037 044 D48 037 047 2~& 223 053 033 20 4 153 1&9 243 054 m 129 64'? 058 063 07 4 \63 RES. WIND SPD. 11 /S ; .... .3 .2 .1 .9 .5 .9 .& . a .\ .1 .4 1 .2 .I 1.7 .4 .3 .1 .o .I ., . ... .5 . 3 .I .3 .2 c . .; .3 1.0 .1 AVG . WIND SPD . ~!S r ..; .& .4 .4 1.0 \.1 .9 .7 .3 .3 .6 .3 .8 1.9 • 4 .s .4 .3 .b .& .6 .. . .; .6 .. ,,J .7 .. . .; .9 1.1 .6 II AX . GUST D!~. D£G 186 220 043 187 947 135 .213 208 215 021 232 074 055 213 229 220 0!;5 212 224 243 21 7 214 005 239 2!e 093 207 103 2C8 198 220 MX. GUST P ' '.'AL !!~AN MEA ~I SPD . DIR. RH t·P HI S Z O~G C 3.2 Sil 2.5 t!E 2.5 ssu 5 .1 t<;£ &.3 SSII 4.4 SSiol 3.8 ssw 2.5 ESE 2.5 NE 5.1 ~ 2.5 NE 2.5 N!iE !. 9 N £ 5.1 Nt1E 1U SW 3 .2 t!~ 3.2 E 3. 8 .Sll I. 9 ENE 3.2 :I E 5 .7 .. sw 3.~ E 3.2 E 3 .8 ~ 2.5 HI~ 3.2 NNE 1. 9 NE U EtiE 5.1 ssw 10.~ EN£ "j.. ~w 27 ~0 lb 20 32 40 33 u u 51 4b 61 H 48 33 ~., t ~ 52 b2 53 H 0 H H H u n H H -4 .3 -7.5 -.6 -12.9 -9 . g -5.7 -3 .7 -4 .6 ***** JUH -3.2 -7.6 ., ***** u -7.8 -. i -1.4 .9 .1 thU •un HI 'Hi '**** H Hl ***** HIH ***** ***** IUH -3.0 GUS T VEL . AT MAX . GUST MIN US 2 INTERVnLS GU S T 1.1EL. ,; T MAX . GU S T Ml NUS 1 I r!TL"::R•H ,L GU S T VEL. AT M ~X . GUST PLUS 1 INTERVAL GU S T VEL . AT MA X . GUS T PL..U S 2 I NTERV ALS ?REC!? !1.~ u 0.3 u .2 .s i.b 3.6 'lO L ~.., .... 19.0 'lO 0 '-••'-' !1.2 9.4 lU 12.o &.0 3 .~ 5. 0 .2 0.1) 0.3 19 .4 &.2 5.4 7.4 s .~ 232.2 C" '1 ...J •• R o ..... 3.9 E .9 S!Jl,;R £E~~·t %~ !.JH /SC~ 25 3~ 2 124~ 3 22!:5 ~ ,c -~ . .,J .... .., 2&!5 7 1275 9 17 19 9 11 90 1: m.s 12 978 12 91C H 2C93 !5 23i3 ~~ 1192 1:- 1488 :s ::s i 9 1291 .: • 33~~ 23 2,!5 .:' ::::o~ ::s 1248 ::, 1m::::- 134 C ~c ! b05 "0 1 -:'E~ ..:v 57! 50 ::.:Ji:::.: :(d_, .. T [I,,.'E ~UM I DIT Y RE.;DI NCS ARE UNREL..H)BLE WH EN WIN'C· S~'::::;::;s t ,r;::_ • ... :·::.~ T:-:,-.. C".·C. ME::-:-EF: P E ::; S t::lOr'L . SU Ch RE.~D II'!C S Hll'.'E NOT Fl EE ~~ H .1C!_!JI:·E L' !IJ T :-E ().;:.! ... ( ·,·' t~l\j :1 T H ! ... Y :"IEt o~'! F D!~ RE L f'of~'~'( HUM rDIT'i' AriD DEW POU'1 f. ~~~ ~J !E S AT l HE B~C ~ OF THIS REP ORT »*»' 162 I~ & M c;: D N S U 1... T ANT ~:) ~ SU S :1: T NA H Y I> I~ ClELECT I~ :1: C PI~ Cl .T EC T MONT HLY SUMMARY FOR SHERMAN WE ATH ER STATION DA TA TAK EN DURING Oc tober , 1982 J RES. RES. AVG. IIAX . MX . DAY 'S 111\X' "IN . I£M II IN) III MD WINJ) GUST GUST P'VM. l£AM I£Aif SOLAR Dlf'l TEMP . TEttP , TDf . DIR. SPD . SPD . DIR . SPD. DIR. RH DP PRECIP EHERGY DAY DE'C DEG C OS C JG IVS "'s DEG "'s I DEG C "" llt/SGM 1 4.5 -.1 2.2 159 .2 .4 211 2.5 EliE H Hill HH 1318 1 2 7.& -1.8 3.3 164 .3 .4 349 2.5 ESE II IHH HII 2088 2 3 7.4 -1.8 2.8 1&7 .9 .7 151 4.4 EM£ H HUt Hit 2351 3 4 7.8 -5 .2 1.3 173 .8 .8 196 3.8 OE II Hilt .... 27l3 4 5 &.1 -5 .9 '1 1&3 1.6 1.7 147 7.& IE II '**" Hit 2751 5 6 5.6 -\.1 2.3 161 1.4 1.5 I?S 6.3 BE H IIHI '"* 19ll 6 7 1.8 -.8 .5 161 .8 1.1 162 4.4 BE II HUt HII 7SS 7 8 1.8 -1.6 '1 148 .4 1.1 127 3.2 OlE H I HII IHI 855 8 9 2.4 -2 .2 .1 216 1.1 .8 212 3.8 ssw H HIH Hit 763 9 1·: -.4 -3.5 -2.1 214 2.3 1.2 219 5.1 ssw It HIH HII 1821 11 H 2.1 -3 .3 -.7 861 1.1 1.1 843 5.7 BE H IHH IHI 7b5 11 12 2.8 .1 t.1 061 .4 .4 047 1.9 ME H Hill IHI 538 12 13 .s -5.2 -2 .4 031 .4 .6 214 3.2 ME H HHI IHI 345 13 14 1.3 -11.5 -5.1 179 1.0 .7 172 3.8 E •• IIHI IHI 623 14 15 1.2 ·14 .3 -&.& 148 .7 .& 028 2.5 £ H HUI HII 15U IS 16 -.8 -7 .5 -4.2 HI IHI .7 Ill IHI HI II IIHI 1111 29'3 16 17 5.1 -8.4 -1.7 126 .3 .4 126 1.9 IIIE H IIIH IHI m 17 18 2.4 -11.8 -4.3 153 .I .4 146 1.9 s H HHI IHI 1541 18 19 .8 -4 .2 -t.7 HI .... .3 IH '"* IH H Hill Hit 243 19 21 .1 -13.8 -6.6 IH till .6 IH IIH IH .. IHH HH 630 21 21 -2.8 -12 .8 -7 .8 167 2.3 2.2 184 7.6 ENE .. IIUI HH 893 21 22 -1.5 -10.6 -6.1 158 2.1 2.3 157 7.0 HE II HHI IIH 1485 22 23 -2.1 -1s .s ~.8 181 1.5 1.6 ass 6.3 E H IHH .... 1241 2l 24 -3 .4 -19 .4 -11.4 176 .6 .7 881 3.8 E H IHH HII 1323 24 25 -4.3 -21.5 -12.9 196 .2 .4 124 1.3 E H I HH HH 1193 25 26 -21.8 -24.6 -22.7 179 .5 .5 177 2.5 EHE If IHH HH lS3 211 " IHH HIH HHt tH HH tHI IH IHI HI H Hill IHI IHIH " 28 IIIH HHI HHf HI IHI HH HI HH HI II litH IHI IIIIH 28 29 litH litH ttHt tH IHI IIH tH IHI IH H HIH .... IIHH 29 30 Hill HHI HtH HI Hit HH IH Hit IH .. HIH . ... ...... 31 31 ..... IIIII IIHI IH IHI IHI Ill HH ... It HHI IHI Ill HI 31 ItO NtH 7.8 -24.6 -3 .5 068 .8 .5 147 7.6 ENE H IIIII Hll 38135 GU ST VEL . AT MA X. GU ST MINUS 2 INTERVALS 5. 1 GUST VEL . AT MA X. GUST MINUS 1 INTERVAL 5 . 1 GUST VEL. AT MAX . GUST PLUS 1 INTERVAL 5.7 GUST VEL . AT MA X. GUST PLUS 2 INTERVALS 5. 1 NOT E : RELATIVE HUMIDIT Y READINGS ARE UNRE LIABLE WHEN WIND SPEEDS ARE LE SS TH AN ONE METER PER SECOND . SUCH READI NGS HAVE NOT BEEN INCLUDED IN THE DAILY OR MONTH LY MEAN F OR RELATIVE HUMIDIT Y AND DEW POINT . *•)(-·)(-·.(-SEE NOT ES AT THE BACK OF THIS REPORT **** 163 ·~ & M CDNb l.JL T(~NTS, :1: NC . ~:> U S :1: T N A H Y l) I~ C) E L. E C T I~ :t: C P I ~ D ,T E C T MONTHLY SUMM ARY FOR SHE RMAN WEATHER STA TION DATh TAKEN DURING NoveMoer. 1982 DAY ltAX . TEKP . DEi: C ~ ltiit. mw . DEG C ltEAH TtJ\P . iiEG C ~ES . WIND DIR . DEG RES . WIND SPD . lt/S IWG. WIND SPD . lt/S IIAX . GUST DlR . DEG !tAX. GUST pI VAL ltEAH SP D. DIR . RH iVS I 11EAH DP PREC IP DtG C 1!t1 DAY'S SOLAR ENERGY DAY lllVSC lt ----------·--------------------- 1 litH 2 IIIH 3 tiHI 4 UIH 5 IIIH 6 ***** 7 Httl 8 11UH 9 ..... 10 "*** 11 HIH 12 0.0 13 -2.1 14 -1.8 15 -10.1 \b HHI 17 IUU 18 .... . 19 .. ... 20 111111 21 ..... 22 11111H 23 B.O 24 -.5 25 .8 2b -5.3 27 -7.5 28 -14.6 29 -4.9 30 -7.8 IIOIHH .8 UIH Hffl ..... IHHIII HIH litH I I HI IIIH litH litH HIH -3 .1 -7 .1 -1 0.6 -16 .9 IHff III II ..... IHH IIIII ..... IIIII -3 .2 -10 .7 -11 .9 -10 .5 -16.5 -20.1 -14 .3 -1 3.~ -2 0 .I GUS T GUST GUST GUST IHH fHH HHt HHI ..... ..... IHH HHt IHH HHf HHt -1.6 -4.6 -&.2 -u .s HHt HHI HHf ..... ..... l fiiH ffHI -l.b -5.& -5 .1 -7 .9 -12 .0 -17 .4 -9 .& -10.4 -7.9 VEL. VE L . VEL. VEL . Ill Ill Ill Ill Ill Ill ... Iff Ill Ill Ill Q81 035 Ill 192 HI Ill HI Ill Ill H4 Ill 038 873 056 ~48 075 0&8 Ill Ill 059 .... 1111 HH fill HH lUI HH 1111 l U I .... HH .9 .2 **** .1 1111 .... .... Uti .... .... U ll .6 .5 .7 .9 .b .3 **** 1111 .b AT AT AT AT MA X . MA X. MA X . MA X . 1111 IIH HH Hit .... .... .... .... .... .... .... .7 .3 .2 .2 **** .... Hit t ill .... IIIII 11HI .6 .5 .a .9 .b .3 8.0 '0 .4 GUS T GUS T GUST GU ST Ill HI Ill HI IH . .. Ill U l HI HI ... 078 352 Ill 992 HI IH ... ttl ... I H Ill 0&1 053 091 844 073 880 07 9 *** 061 MINU S MINUS PLU S P LUS HH HI lUI IH IIH Ill ....... 111 1 IH HH HI lUI ... I HI Ill Hit Ill .... IH HH Ill 3.2 E "!.9 EHE IIH HI 1.3 E .... Ill 1111 HI IIH HI 1111 IH lllf Ill IIH HI HH Ill 3.8 NNE 1.3 EHE 3.2 EN£ 3.2 HE 1. 9 El£ l. 9 EHE .b ... H it HI 3.8 ENE .. fl H .. H .. .. II .. .. .. 25 44 .. H .. H .. H .. .. .. 33 H 2& 34 38 22 37 28 32 111111 IIIII IIIII UHI ..... IIIII IIIII I IIIII Hilt IIIII HIH -1 9.7 -14 .3 IIIII IIHI IIIII Hill 111111 .. ... Hilt H ilt litH -t 5.U litH -22 .4 -25 .2 -20 .9 -33.3 -21 .9 -26.8 -22 .1 2 I NTERVA LS 1 IN TERVAL 1 IN TERVA L 2 INT ERVAL S till lilt II I I .... HH IIIII HII ltH 1111 I HI Ill• 1111 1111 HII 1111 l ilt lilt 1111 lilt .. .. 1111 Hit lilt 1111 1111 .... lin IHI IHI 1111 lilt '1 .3 1 '3 1. 3 1 '3 tttttl I 111111 2 1 11111 3 ...... 4 111111 5 111111 6 :tiltH i lltflt 8 llllfl 9 111111 10 ...... 11 178 12 278 13 233 14 171 15 ****** 1& IIHH 17 filtH 18 ...... 19 **"** 20 IIHII 21 ltflll 22 275 23 2&8 24 273 25 270 2b 245 27 2&8 28 19Q 29 lbO 30 2799 NOT E : RELATIVE HUM IDI TY ~EADINGS ARE UNRELIAB LE WHEN WI ND S PEEDS ARE LESS THAN ONE METER PER S EC OND. S UCH R EADI I~G S HAVE NOT BEE N INCLUD ED IN TH E DAI LY OR MONTHLY MEAN FOR RE LATI VE HUMIDI TY AND DEW POI NT. ***» SEE NO TE S AT THE BAC K OF THIS REPORT **** 164 I ~ & M c; D N ~:> U 1 ... T ANT S ,.. MONTHLY SUMMARY FOR SHE RMAN WEATHER S TATION DATA TAKEN DURING DeceMber> 1982 ( RES . RES. AVC . HAX. IIAX . DAY 'S IIAX. 111M. HEAK' WIND WIND WIND GUST GUST p I VAL MEAN MEAN SOLAR DAY TE!IP . TEtiP . IDIP. DIR . SPD. SPD. DIR. SPD . DIR. RH DP PRECIP ENERG Y DAY DEC C DEG C DEC C DtG lt/S 11/S DEG 11/S % DEG C Mit WH /SQII ----·-------·--------·-·------------·------ -12 .1 -18.0 -15.1 071 .7 .6 106 3.2 NE u I IIU UH 203 2 -16.9 -21.9 -19.4 047 1.2 1.3 029 4.4 NNE H *'*** !IU! 220 2 3 -14.5 -24.5 -19.5 864 t.O 1.0 030 3.2 ENE II Hilt I Uti 227 3 4 -13.4 -18.2 -15.8 044 1.2 1.2 050 3.8 HE lilt Hill HH !03 4 5 -2 .3 -14 .0 -8.2 057 1.5 1.6 083 4.4 HE II IIHI lUI 275 5 6 .4 -9 .2 -4.4 oss 1.4 1.5 063 5.1 ENE u **"* nu 283 ~ 7 4.0 -1.1 1.5 056 u 1.4 046 6.3 t4E u IHII lilt 243 7 8 .9 -.4 .3 Ul 0.0 0. 0 Ill 0.0 liH ll!l Ill HI lllll 200 8 9 1.3 -15.8 -7.3 101 .2 .a 178 6.3 E Ill II HI HH 203 9 10 -5.1 -19.4 -12.3 087 .7 .7 111 3.2 E H Ill Ill HU 258 10 11 -2.4 -8 .7 -5 .6 064 1.5 1.6 030 3.8 EHE II IHU Ulf 231 11 12 . 4 -5.7 -2.7 059 1.4 1.5 042 4.4 ENE H IIIII lUll 270 12 13 1.1 -7 .6 -3.3 063 .B .9 GS2 3.2 EHE II litH IIH 241 13 14 -.2 -8 .9 -4 .6 843 1.0 1.2 335 4.4 EHE II 1!1111 UH 258 14 15 2.2 -8.7 -3.3 663 1.2 1.3 065 3.8 ENE ** IIIH 1111 241 15 16 -.3 -8 .9 -4.& 048 .9 1.0 029 3.2 HE u Hill nn 238 16 17 -2.a -14.1 -8.5 062 .4 .4 oa6 1.9 ENE II IIIII UH 23 1 17 18 -13.4 -18.9 -16.2 055 .3 . 4 075 1.9 ENE Ill Hill I HU 255 18 19 -4 .5 -21.1 -12.8 039 .9 1.0 052 4.4 NNE Ill !!fill lUI 228 19 20 -6 .3 -tb.4 -11.4 056 .9 1.0 012 3.8 EtlE lll tun UH 263 2~ 21 -14 .9 -22 .7 -18 .8 oa2 .8 .a oa8 1.9 E H HIH IHI 241 "l1 ~· 22 -19 .9 -2~.6 -23 .3 072 .6 .7 090 2.5 ENE H Ulllll un 2~8 22 23 -11.2 -22. I -16.7 054 .a .a 031 2.5 ENE u ll!fU uu 258 23 24 -8 .0 -19.4 -13.7 069 .a .9 OSe 2.5 ENE H Hill Ul!l 229 2~ 25 -a.4 -17 .5 -13 .0 060 .7 .a 020 2.5 ENE u HUI Ull 203 25 2o -1.4 -7.5 -4 .5 oss 1.1 1.2 061 3.a ENE II IHfl un 24a 2& 27 .1 -4.3 -2.1 069 .4 .4 082 1.9 ENE fl IIIII 1111 171 27 28 .4 . I .3 063 .4 .2 092 1.9 NE fl IIIU Hill 173 29 29 .9 .1 .5 092 .2 .~ 102 3.2 HE ** IIIU Ull 173 "lO ~· 30 1 r .. .J -5 .6 -2.1 221 .s .6 22o ') r .... .J sw n IIIU H llf 223 30 31 -2.5 -6.7 -4.6 IU 1!111 uu *** lUI Uf H Hill UlU 165 31 MONTH 4.0 -26.6 -a.7 059 .9 .9 046 6.3 ENE ** HUll HU 7187 GUST 1.JE L. AT MAX. GUST MINUS 2 INT ERV ALS 5 . '7 GUST VEL. AT MAX. GUST MINUS 1 IN TER VA L 5. 1 GU ST VEL. AT MAX. GUS T PL US 1 INTEI~Vf.'lL 4.4 GUST VEL . AT MA X. GUST PLUS 2 IN TER VALS ~ ':l ~ . .:.. NO TE : RELATI'JE HUMIDIT Y REA DI NGS ARE UNRELIABLE WHEN WIN D SPEEDS (',RE L;~:s E THAN ONE METER PER SECOND . SUCH READit-'GS HAI..1E NOT BE EN I NCLUD ED lN THE DAIL Y 01~ MONTHL Y MEr~N FOR RELATIVE HUMIDITY r~N D DEW POINT. Y:lHH· SEE NO TES AT THE BACK OF THIS REPOR T ·X··~·X ·~ 165 . ~ C U i'-J b U 1... T i::O. N T ~:~ :• :1: NC . H Y D I ~ C) 1::: 1... E C T I~ :1: C P I~ C .IJEC T MONr~Li S~MMA~Y FOR S~ERM AN ~EA T~ER STATIOh DA TA T A~E~ D0R ING January~ l98 3 t Rt:5. nAX . IH~. 1\tAH WHi D DAY m1r . i t!IP. TBIP. OIR . DEu C. ut:G C utb C DE\. 1 2 3 4 s 0 i a 9 10 11 12 13 14 15 to 17 16 19 20 21 22 23 24 25 26 27 28 21 -.9 0.6 -3 .9 -6.9 -18 .0 -14 .3 -lid -lo .B -20 .5 -17.7 -11.9 -14 .2 -14 .3 -7.9 1.& .7 -3 .4 2.3 0.0 ..... UUI UIIU HtU "'** ltttU ~uu ..... IOU 3u ~uh 31 uau nurHH ~.:5 -s .u -5.8 -7.1 -z u.s -25 .8 -2u .u -2 9.5 -32.2 -2 7.u -2 7.8 -25.9 -1 7.6 -17.9 -29 .7 -13.5 -5 . a -13.4 -1.4 -&.2 ****~ tun IUifll tUu "*** HUll ***** 11-tUt UUI -3 .a u• -2.9 lilt -5,5 Hit -13.9 *** -21 .9 tit -11.2 oot -2.2.9 058 -24.5 a&u -23.8 035 -2.2 .8 u54 -18 .9 062 -15.9 ObB -1&.1 Ob8 -14.3 m -6.0 &47 -2 .2 043 -8.4 ~62 -3 .6 aoo -3.1 m ..... lid tun ut ..... Itt HIU Ut IHill lfll IHU till llltU HI IIIIHI Ut l tflil ... AJttt ~lltfll *** ttttt ttt** tltt -32 .2 -13 .v u59 Rt:S. wiNil SPil . 11 /S A!JG . IIAX. wiND GUST SPD. Dli<. n/5 Dt:G tttt Uitlt UU IIlii ttU UH .... ***' nu tttt: 3.4 3.1 2. 0 2.1 1.8 1.5 1.2 1.3 . 9 1.2 4.2 4.4 2.4 2.5 2.1 2.2 1.1 1.2 1.7 1.8 .8 .9 .3 .b i.3 1.4 .2 .b tlltt Ullll nu uu Htf 11111 uu .ttlt 11111 .... tiU tUt ilffl Hill HU tiiU 111111 Hllll Itt ... ... Hll Ut ub2 u51 OS~ 04il 653 669 05b 077 071 070 054 215 u&s 227 Ul ttl ... Itt *** Ut *** IIIII ... liAX . GUST pI VAL IlEAl! r!t:Aii SrD. DlR. KH ilr rRt:Clr 1VS X DEG C I'IH uu tt:t h 1111111 *" " Uti IU ill Utll Itt Ill Ult Ut It 7.o t.NE ** i . 0 ENE n &.9 lit ilt 3. 6 Nllt tt 5.7 NE t11 12 .1 EN£ u 8.9 ENE u 7 .b Eilt n 4.4 Ejjt: u 5.7 ENE u 5.1 tl E u 2.5 ENE u 7.0 ENE u 5.7 Eht: u 111111 ... ** 111111 lilt .. fUll ... ** liiiU liH tit IHll llff U ttllt *" u Hill 111111 H tttl Ut U .... 11ft 1111 U-H filii liiiU Ut 12.1 ENE ... u d Utltt !Hit IIUf HH tltH tUt UIIH UU tlll*t ttd HUll UH UUf UU UHII tift ltttll .... sHill Hit tUtt IH!t ..... 111ft HUt lUI tflltll .... ttttlt Hltt ..... IIHf Utili UU **"** tllllll ttftll ttllll IIUU llllll ltiUI Ull* llllfll11 IIIli fttll htt lllltllll iiUI ttlllli .... Ut:lll llfllll lltHI Hfl ..... lUll ~uu u ·u t'H U Ultlt HUt Utf INTERV AL S INTERv AL INTERVA L GuST vEL. AT MAX. GUS T MINU S 2 G0 ST ~EL. AT MA~. G~ST MINUS 1 G0S T VEL. AT MA X . GJ ST PLL iS 1 GuST VEL . AT MA X . GUST P LUS 2 ItHERVAL S 8 .3 8.9 10 .2 7.0 DAY 'S SOLAR ~E~G·f ilAY wSiln 2u& 1 220 2 l8d 3 2o6 4 2·i & ;:, :m i> 323 7 358 a 355 9 348 10 528 11 43a 12 39 3 13 405 14 345 15 333 16 228 17 2i5 18 171 l'i IUIIltf 2U I UIIH 21 ...... " ...... 23 ...... 24 .. .... 25 tlii.U~ 26 UHH 27 ...... 28 n~• 2~ HUh 3u non 31 599c N Ul ·~: R£LAT i~E nJ M I~ITY ~E AD INGS ~RE UNRELIABLE WHEN WIND SPEEDS ARE LESS ThAN ~NE METER PER SECON D. SU Crl READINGS HAVE NOT BEE N INCL UDE D I~ ThE DAIL\ OR "O NTnLY MEA~ FOR RELAfiVE nuMID I TY AND D E ~ PO IN T . ~ .. "·"·~: SEE NGTES AT Trit: BACI\ OF T ·~IS REPORT ~a ·X· 1 66 I~ ~ M C ONSUI ... TANT ~::> .:· TNC. SU~:> :t : T N A HYD I~ DFLEC TI ~ :1: C PI~ D . .TECT MONTHLY S UMMARY FO R SHFRMAN WF.AT HFR S T ATJ:ON DATA TAKEN DUR!Nf:; f7ehrllc:trv , 1983 DAY !tAX . rnt . DECC 1 IHH 2 HIH 3 IHH 4 IIIH 5 IHH b HIH 7 -.1 R -1.9 9 -9.1 t8 -7.5 11 -11 .1 12 -11 .5 13 -24.7 14 IIIH 15 HHI 16 IIHI 17 IHH 18 ..... 19 IIHI 21 IHII 21 IIIII 22 ..... 23 IIHI 24 IIIH 2S IIIII 26 IIIII 2J '**" 28 HIH 110HTH -.1 II IN . TtMP . DEC C IHH HHI IHH IHH IHII Iliff -8.3 -13 .& -21.9 -23 .3 -26 . t -28 .1 -29 .1, IHII IHH Hill IIIH HHI IIIII IHH 141** 11411 ~~n• ""*I IIIII ..... Hill ''*** -29.1, l1EAH Tflf. DEC C IHH IIIII *Hit IHH IHH IIIII -4.2 -7 .R -15.5 -15.4 -18. I -19 .3 -'lJ.2 IHH ..... IIIII IIIII IIIII IIIII IHH IIIII IIIII IHH IHH IIIII IHH IIIII IHH -15.3 GUST VF L. l.lJ GT ~)F.l. . f.:lJ S T V E L. GIJ S T lJ r::J... RES . WI HI) DIR. DEC IH IH I ll IH Iff Ill 099 872 176 178 859 1&1 14~ IH IH HI IH HI HI HI Ill HI Ill Ill HI Ill Ill Ill A6 9 RES . AlJG . Wltro WIHD SPD . SPD . K/S 11/S .... Hlf 1111 IHI 1111 IH'f 1111 HH 1111 1111 IHI I!!H .4 .6 .2 .3 .5 ,, .4 .s .s ·" .3 .s .4 .4 1111 HH 1111 HH 1111 HH 1111 IHI 1111 HH HH Hll 1111 fHI Hit 1111 Hll HH IHI .... HH HH IHI fill 1111 1111 IHI HH Hit HH .4 .~ HAX . GUST DIR. DEG Ill Ill ... Ill Ill Ill 073 047 145 095 144 141 127 Ill HI Ill HI Ill HI Ill Ill Ill Ul Ill IH Ill IH Ill 847 AT ~lAX . AT MA X. AT ~lAX. AT MA X. I.UST MTNlJS f:;IJ ST Ml:NU S GU ST PI..US f:;I JST PUIS !tAX. GUST pI VAL MEAN I(AM SPD . DIR. RH DP PREC IP li /S I DEC C HN HH IH Hit Ill IIH Ill HH HI IIH H* HH IH 2.5 F. :u E 2.5 E 3.2 F.HE Vi HE 1. 9 F.H£ I. 3 Elf: 1111 IH 1111 HI 1111 IH IIH Ill Hit Ill IIH HI HH Ill 1111 IH HU IH IHI IH Ill* '" 1111 Ill lUI IH IHI Ill IHI Ill 3.? ENE II IHII 1111 H HIH IHI U IHH HH H IIIII IIH H IIIII 1111 H llllf Ill* II Iliff 1111 H IIIII JHI H IIIII Hll H 1HH IHI H Ill** 1111 II IHH HH II IIIII ltiH II IHH 1111 II llllf IHI H IIIII IHI II IIIU HH H IHH 1111 II IIIU HH H IIIII 1111 II IIIII 1•11 H IHII 1111 H IIIII 1111 II IHH HH II IHlll 1111 II IIIII Hll II I liff IIH H HlfW IHI II IHfl U ti 2 INTF.RVAI .S JNTERVAL HITFR~JAL 2 J:N TERO AL.S 1 . :3 1 . ~ 1 . 9 DAY 'S SOLAR EHF.RGY DAY w:v SQII 111111 1 HHII 2 IIHH ~ HHII 4 IIHII 5 '***" b 1,52 7 733 B tm 9 t 118 10 1215 1 1 1305 12 398 13 111111 14 IIHH I S 111111 16 IIHH 17 '***" 1R 111111 19 '***" 21 11*111 2 1 111111 ?.2 ****" 23 IHIH 24 ...... 25 I HIU 2h "***' 27 111111 28 6555 NOTE : REI..A TIVF HUMIJHTY READ"T:NGS ARF UNRFL.JAFII..F" l~HF.:N I.<HNP S F'F.F.:DG ARF l.Fr-S THAN ONF: MF.TF.R PF.R SECOND. S I H";H REAIHNI.S HAIJE NOT F.IEF.N l:N I';LIJD~D IN fHE DAT.LY OR MONTHLY M[AN FOR RELATI VE HUM JDITY AND DF"W POINT. ·~-H--~ SF.F. NO T F.S AT THE BACK OF T IHS RFPilRT ~-*·U 167 ·~ & M r :~ D N ~:> U L. T A N T ~:> > :t:NC . BUn:I:TNA H Y l> I~ 0 E 1... E C T I~ :t: C PI ~D ,TEC T I MONTHL Y SUMMARY FOR SHERMAN WEA THE R S TATIO N I DATA TA KEN DURIN G Mar c h , 198 3 I RES . RES. AUG . MX. MX. DAY'S !tAX . KIN. HEAH wnm WIND WIND GUST GUST P 'IJAI.. !lEAH KEAN SllAR DAY TEMP . TEMP . TE1tP . DIR. SPD . SPD . DIR . SPD . DIR . RH DP PRECIP ENERGY DAY DEC C DEG C DEG C DEG 11/S 11/S DEG 11/S % DECC ttl WH/SQI! I I tfHI llfH llfH IH IIH IHI Iff Hfl IH H II HI IHI HHfl 1 2 ..... Hfll IHff Ill llfl IIH Ill HH HI I! Hlfl Hfl ...... 2 I 3 ..... IIIII lfHI IH 1111 Hit Ill 1111 IH II IIIH 1111 HHH 3 4 IHH lfHI ..... HI 1111 IHI Ill Hll HI .. IIIH HII IHHI 4 s IHH IIIII Iliff IH IHI Hll Ill HII Ill .. IIIH IHI HHH 5 b llfll HHI ..... HI HH .... IH HH Ill •• IHII IIH HIIH b I 7 Iliff IHH lfHI Ill HH HH ... llfl Iff II llfll .... HI HI 7 8 IHtf lfHI lfHI Ill HH HH ... Hf ~ ... H lfHI HH HIHf 8 9 HIH lfiH lfHI IH HII 1111 HI 1111 Ill H IIIH IHI HIIH 9 I tl -2.6 -15 .1 -8.9 Ob1 1.2 t.J 074 4.4 EHE H IIIH HH 255b 18 tt 4.4 -7 .8 -1.7 05b 1.0 1.0 853 3.8 ENE •• IIIH IHI 191J 1 1 12 8.6 -8.3 .2 163 1.1 1.2 Ob2 4.4 ENE H lfHI HH 1991 12 I 13 8.b -11.5 -t.l ObB .9 t.O 07b 4.4 ENE .. IHH Hll 2798 13 14 5.3 -11.2 -3.1 tb9 .9 .9 07S 3.8 fME II Hill Hfl 2278 14 15 8.5 -8 .5 ••• 865 .s .7 010 3.8 E II IIIH IHI 2468 15 1b b.8 -10 .4 -1.8 lb8 .8 .9 076 4.4 ENE .. lfHI .... 3888 16 I 17 6.4 -13 .9 -3.8 87b .8 .a 084 4.4 ENE h ..... **" 3255 17 18 6.1 -15.7 -4.9 169 .9 1.0 069 5.1 E H IIIH Hit 3355 18 19 5.9 -15.8 -5.1 873 .8 .9 0?8 4.4 E ** IIIH .... 3423 19 1 20 IHH Hffl llfH Ill 1111 1111 Ill HH HI H lfHI HH Hflfl 20 21 ?. I -10.3 -1.6 069 1.1 1.1 0?2 4.4 EHE H IIHI lUI 3423 21 22 ?. 1 -15.0 -4.1 17S .b .? 085 3.8 ENE II lfHI .... 3529 22 23 5.9 -14 .8 -4.5 lbB .? .a 8?9 4.4 ENE II ..... IIH 3618 23 24 4.? -11.9 -3.6 052 .8 .9 06? 3.8 ENE II ..... **** 2533 24 25 5.2 -8 .8 -1.4 063 1.4 1.5 081 5.? ENE .. IHII .... 3695 25 2b s. 1 -8.3 -1.6 15C 2 .8 2.0 049 ?.b ME II Hill 1111 3435 26 27 4.3 -7 .9 -1.8 059 1.9 1.9 052 ?.0 ENE H HHI IHI 3663 27 28 5.8 -9 .9 -2.1 065 1.4 1.5 077 5.1 ENE H Hffl Hll 3799 28 29 7.6 -11 .7 -2.1 077 1.1 1.1 071 4.4 E H IIHI I HI 3958 29 30 6.5 -12. I -2 .8 872 1.2 1.2 077 5.1 ENE II lfHI .... 4228 30 31 18.0 -8.0 t.l 865 .7 .8 055 3.8 ENE fl Iliff IHI 3553 31 ltOHTH 18.0 -15.8 -2.b 865 1.0 1.1 049 7.6 ENE II IIIH .... 66524 GU S T VEL . AT MAX. GUS T MI NUS 2 I NTER VAL S 5.7 GU ST VE L . AT MA X . GUST MINUS 1 INTERV AL 5 .7 GUST VEL . AT MAX . GUST PL US 1 INTERVAL 6 .3 GU ST VEL . AT MAX . GU S T PLUS 2 INTERVALS 6 .3 NO TE: RELATIVE HUMI DI TY READING S AR E UNRELIABLE WHEN WI ND SPEEDS ?IRE LE S S THAN ONE METER PE R SECOND . SUCH READINGS HA VE NOT BEEN IN CLUD ED IN TH E DAI LY OR MONTHLY MEAN FOR RELAT I VE HUMIDIT Y AN D DEW PO I NT . ·X· .X.·~·~ SE E NOTES AT THE BACK OF THIS REPORT ·~·X··lf ~· 1 68 S l .J S :J: T N A MONTH LY SU MMAR Y FOR SH FRMAN WEATH ER ST ATIO N DATA TAKEN DURING Apr1l , 1983 ~ES. RES . AVG. MAX. l1 AX. fl AY'S MX . MIN . "EAM WIND III MD IIIHD bUST GUST P 'VAL ltEAH tiEAH SOLAR DAY TEltP . IDif'. TiMP . DIR. SPD. SPD. DIR . SPD. DIR. RH DP PRECIP ENERGY DAY DEGC DECC DEGC DEG "'s "'s DEC ri/S z DEC C l'il WH/S~ -------·-----·---------------- 1 9.2 -11 '1 -.5 071 1.0 1.1 082 ~.~ E II ***** 8 '6 42~3 1 2 9.b -8 .8 .~ 0&9 1.0 1.1 082 5.7 EN£ II UIH u.o +US 2 3 8.3 -18 .7 -1.2 0&3 1.2 1.2 1&5 ~.~ ENE H: ..... 1.0 4500 3 ~ 7.& -.5 3.& 135 .2 1.9 212 10 .2 N£ ** IIIII 2.2 1903 ~ s s. 1 -2 .~ 1.~ 853 .2 .b 352 3.2 EiiE II Hlllil 2.6 20&5 5 6 2.6 -11.3 -~.4 09& .8 1.1 120 4.4 E .. Hill 2.2 -4948 b 7 i.S -4 .5 1.5 18~ '1 .2 86~ 2.5 ENE ** UIH 0 '0 4528 7 a ~.~ -5 .4 -.s 235 .a .8 223 4.4 Sll .. I Hit u 390a a 9 3.7 -9.5 -2.9 217 .8 1.0 218 3.8 ssw II lit II .b 3155 9 iO 2.& -11.3 -4 .4 09& .a 1.1 120 ~.4 E .. Hill 0.0 4948 10 11 -1.9 -11.7 -&.a 957 1.3 1.4 835 5' 1 ENE H tiiH 0.0 2727 11 12 3.4 -4 .3 -.5 839 .1 .7 038 3.2 HHE H IIIII 8.4 2078 12 13 7.4 -3.8 1.8 ·~ .7 .b 046 3.2 t It IIHI 4.0 4438 13 14 5.1 -.9 2' 1 220 .a .9 229 ~.4 511 .. Ulll 5.0 2715 \4 15 ~.5 a.o 2.3 041 .3 .5 211 2.5 HHE .. ***** 14.2 2:75 15 to 7.b -1.7 3.0 Obb 1.3 1.1 059 5 .'I ENE H Hill 1.8 3900 1b 17 s. 1 -5.3 -' 1 218 .9 1.2 231 . 5.1 SSII H ..... .2 4218 17 18 7 .0 -1.3 2.9 052 .b .8 020 5.1 ENE ** UHI 11.0 jS8t 18 19 7.5 -3 .3 2.1 210 .5 1.2 28& 4.4 ssw ** *"** 8.0 3908 19 20 9.9 -4 .3 2.8 971 .9 1.1 077 5. I E .. Hill 8.0 5030 20 21 10.1 -4 .5 c.a 093 .o .8 031 3.8 ENE H IIIII 0.0 5143 21 22 a.8 -2.2 3.3 214 .2 .5 1&9 4.4 s II Hill 3.4 3503 22 23 7.6 .5 ~.1 268 • I< 212 3.2 511 II IIIII &.4 3148 23 .. o.J 24 15.1 . 1 7.b 023 .5 .9 001 4.4 ENE .. IHII 0.8 6030 24 25 19.4 -1.& 8.9 183 .3 .7 19& 3.8 t H IIIII 0.0 &008 25 2& 14 .3 -3.7 5.3 315 .3 .b 305 3.2 lUI II II Hill o.a &028 2& 27 14.8 -3 .7 5.6 225 '1 .7 1&& 3.2 HE H ..... 0 '0 &113 27 28 1~.5 -2 .9 3.8 2!5 .b .8 212 5.1 5511 It Hit I 0.0 4195 28 29 10.& '1 5.4 15b .1 .4 210 2.5 EME II HHI b.O 4245 29 Ji 13.7 -2.0 5.9 042 1.0 1.2 U7 5.1 ENE II IIIII 8.0 &590 30 nmtTH 19.4 -11.7 1.8 084 ,,) .9 212 18.2 ENE II tltlll 08.0 124388 GUST VEL. AT MAX. GUST MINUS 2 INTERVAL S 9 .5 GUST VEL . AT MAX . GUST MINUS 1 INTERVAL 8 .11 GUST VEL. AT Mf!rX. GUST PLU S INTERVAL 8.9 GUST VEL. AT MAX. GUST P LUS 2 INTERVALS 7.0 NOfE.: REL ATIVE HUMIDITY READINGS ARE UNRELIABLE WHEN WIND SPEEDS ARE LESS -:-HAN ON E METER PER SECOND. SUCH RE ADINGS HAVE NOT BEEN lNCLUDED I r~ THE DA l LY OR MONTHLY MEAN FOR REL ATIVE HUMIDIT Y AN D DEW POINT . ·X· ·X, ·X, ·X· SEE NOTES AT THE BACK OF THIS REPORT ·X· ·X· :X· ·Xo 1 69 I~ & M C D N ~;; U 1... T A N T S ;.. :J:Nc. SUn :J: T N A H Y D I~ C) E 1... E C T I~ :t: C P I~ CJ S E C T MONTHLY SUM MARY FOR SHERMA N WEATHER STATION DATA TAKEN DURING May .· 1 9 83 RES. RES. AVG. IIAX. HAl. DAY 'S 111\X. MIN. I£AN WIHD WIND WIND GUST GUST p I VAL ltEitH l'lAH SOLAR DAY TElV'. lE.JW. lEW. DIR . SPD . SPD . DIR . SPD. DIR. RH Dfl PRECIP EHERGY D.:.Y DEGC DEG C D£G C DEC lt/S M/S DEG M/S I DEC C "" WH/SOit 1 14.4 -3.7 5.4 127 .3 .8 204 4.4 ENE H HIH .b 5418 1 2 8.2 1.1 4.7 219 1.1 1.2 21& 5.1 Sll ** ***** 5.1 4123 2 3 8.8 -.1 4.4 2&8 1.1 1.3 214 4.4 SSII H tHH .8 4&18 3 4 11.9 -t.b 5.2 056 .7 1.1 128 5.1 ENE II UIH o.o 5821 4 5 12.3 -.8 5.8 043 .s l.B 347 5.7 E H ***** t.O b433 5 b 14.3 -2 .2 b.1 ass .8 .9 351 5.7 ElfE •• tiHI 0.1 7Dt5 b 7 15.4 -2 .2 b.b 041 .b .9 347 5.1 E II IHH 1.0 &853 7 8 1o.9 -2.5 7.2 318 .2 .8 213 3.8 liE H HIH 1.8 b955 8 9 15.8 -.5 7.3 244 .4 .8 263 4.4 ssw II HIH t.O 5983 9 10 14.0 -.8 b.b 233 .s .9 293 5.1 sw If UIH 0.0 o283 11 11 1&.8 -.8 8.0 341 .2 .8 31b 3.8 ESE If **"* 8.0 b7b5 11 12 14.5 2.2 8.4 127 .4 .7 130 3.8 ES£ If UIH Q.l 5783 12 13 1&.4 2.4 9.4 001 .2 .8 017 3.8 ESE H Hill 0. 0 5iB3 13 14 tb .1 .9 8.S 223 .5 1.0 195 5.7 ssw .. UHf .2 4833 \4 15 14.2 .3 7.3 237 .3 .8 234 3.8 E H HIH 0.0 4793 15 16 13.b -.3 b.7 238 .b 1.0 218 5.1 WSW .. ***** t.Q 4183 1b 17 11.8 3.1 7.1 222 .8 1.8 184 7.1 Sll II ..... 7.0 35 28 17 18 11.4 2.7 7.1 222 1.1 1.3 22S b.3 S\1 II ***** .b 4&38 iB 19 12 .7 t.b 7.2 21b .s .9 199 4.4 sw If ..... 0. 0 4285 19 20 18.2 t.B 18 .0 237 1.3 1.5 234 &.3 WSW II HIH ••• boiS 20 21 11.1 4.b 7.9 216 1.3 1.4 25 3 &.3 ssw H ..... 1.4 330~ 21 22 14 .S S.1 9.8 227 .9 1.2 272 5.7 sgj II ***** 2.1 SObS 22 23 14 .4 4.1 9.3 2tb .9 1.2 227 5.1 SSII H HHt .4 4973 23 24 lb.4 -.1 8.2 878 .b 1.8 090 5.1 SE II IIIH 0.0 5889 24 25 1.8 -2 .2 -.2 lOS .2 .2 145 .b ESE H IHH .4 9bl 25 2& IIHf UIH ***** Itt **** HH tit 1111 IH II IHH IIH IHIH 2& 27 !IIHt *"** ...... !Ill Hit litH *** **** IH H HIH Hit IHfH 27 28 *'*** tfftt HIH Ill Hit .... HI IIH IH II ..... IHt ****** 28 29 I Hit tHII ..... IH IHI IIH Ill fill HI II *'*" "** ****" 29 30 IHH !IIIH *"** Ill **" .... Ill **** IH If lfttt 1111 ...... 30 31 HHI IHH ..... Ill fill fHI Ul .... IH H HIH Hll IIIIH 31 IIOlilH 18.2 -3.7 &.9 217 . 3 .I 184 7.0 ssw II Hill 19.4 131075 GUST VEL. AT MA X. GUST MINUS 2 INTERVALS 3 .8 GUST VEL. AT MA'X. GUST MINUS 1 INTERVAL 3.2 GUST VE L. AT MA X. GUST PLUS INTERVAL 5.7 GUST VEL. AT MAX. GUST PLUS 2 INTERVALS 3.2 i·WTE.: RELATI VE. HUMIDITY REA DINGS ARE UNRELIAB LE WH EN WIND SP EED S ARE LESS THAN ONE METER PER SECOND . SUCH READINGS HAVE NOT BEEN INCLUDED IN THE DAIL Y OR MONT HLY MEAN FOR RELATIVE HUMIDITY AND DEW POIN T . ·X··X··)(o ·X· SEE NOT ES AT THE BACK OF THIS ?EPORT ·~·~·)1 .. )(- 170 S(P 1 q82 2 ~528 l ALlE[t •A. ALASK A l A L K[(l~A AIRPORt LOCAL C LIMATOLOGICAL DA T A W[A SYC CO NtR ACt ~E l 085! Monthl y S u mmary (L£iAIIG N IG ROUNOI 3 ~5 F£(1 O£GR([ OilS W[AIH[R ll P[S SNOW II[RI6[ WINO SU NSH I K( I so tOV (q I l["P[RA lUR[ 0 f IC£ oq(CIPIUIIO N SII IIO I SA>£ o5•r I FOG P[LL[IS PA(SS UR[ '" p H I ' I I(~IMS I I I .. --· l •[AV! 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J )q 21 0 I 0 I~ 0 }q 24 J • I I s J 8 18 10 2' 30 0 31 ~2 2 ]q 23 0 I 0 . 2 0 }q 2 I 17 • I 0 • 28 10 JO I i su n sun IO IAL IO IA L N Un B(~ or OAT S 'DI AL 'Oi l L <O~ IH[ •O~I M ! IOilL : s~• :u't 1 sa 1 II 83 $&1 0 7 ,, 0 I 8 18 '" AV G AYG . AI G. ~[P ~'I& OEP . O£P ~A£CI PI UllOM O[P AI[' ,. II\ \I l l( t:.lll hl AYG ,,, ~2 Jq 4!.. I 0 ·• 0 > 01 INCH 2 4 J 02 NUftt[A Of OilS SE ASON 10 OAI[ SNOW, ICE ~[ll[IS GR(AI£S I I N 2' HO URS ANO OAIES GR £ A 1£ S I 0£ P IH ON GROU ND or IOI AL IOI AL ; I 0 INCH 0 ftA I I nun H ft P. •I ~I ~U ~ I(•P 10q ' I HU~OERS I QR ft S 0 ?P(C!PII l iiO H SNOW ICE PHLEIS SNOW, I([ P(lL[lS OA IC [ u o Oll[ I I qoo ( 32" I 12° ; oo O£P OEP H(AYI FOG 0 I }; I 2 · I l 0 0 0 0 ' 0 ·I 2 -5 CL EAR PIA 1L r CL OUOl CLO UOT t EXlRE "E fOR rH( HONlH · LAS t OCCURRE NCE If MORE TH ~N ON( I TRACE AMOU Nt • ALS O 0~ EA RLIER DATE ISI HEAVY FOG : V!SIBIL!TT 1/4 HI LE OR LESS BLA NK ENtRIE S DE NOtE MI SSl ~G DATA HOURS OF OPS MAT BE QEOUCEO GN A VARIABLE SCHEDULE DATA I N CDLS b AND 12-IS ARE BASED ON 7 OR MOR E OBSER VAT IO NS ~~ )·"OUR INTERVAL S RE SU LTANt WIN O IS THE VE CTOR SU M Of WI NO SPEED S AND DIRE CTION ~ DIVIDED BY t HE NUMBER or OBSERVAtiO NS ONE Of lH REE WI NO SPHOS IS GI'IE N UNDER FASTE SI MIL [: r~s;~S T MI LE · ~IGHE SI RECORDED SPEED FO R WH IC H A HllE or WINO PASS ES S 'Ql !ON lO!R(CTIO N I N CO ,PASS POI NTS I FASIEST OBSER VE D OHE MI~U T E WI NO · HIGHES T ONE MINUTE SPEED !D IRE CTIO N I N TENS OF ~EGRE E SI PEA k GUST· HIGHEST I NSTA NTA NE OUS WI NO SPEE D !A 'PP£ARS I N -~E GI REC I!ON COl "HN I EORORS WILL 8[ ~OR'E CI E ~ 'NO C~A HGES I N SU MMA RT OAlA •I•L 9E INH OT ~IEO I, •E !N~U A L DIJ8ll (~I ( ON I CERIIFY t H•t !H IS IS ~H OfFICIAL PUBLICAtiON Of TH E NA TIO NA L OCEA NIC ~NO AI"OSPHERI • AO"INISIRATION, AND IS CO "P ILEO fRO M RECORD S ON fiLE Al THE NAT IO NA L CLI "Al iC CE NtER , ASHEVILLE, NORIH CAROLI NA , 29901 /f4.1-kd- n 0 a a Uli OU l OCEUIC UO /(MY!ROMft[MliL OAU UDj Ul !O UL Cll ft ATIE C£MIER moSPHER I£ I Oft!NISlR AI IO N I Mf OR W IO I SERYICE I SHE VILlt . NORtH CAROLI NA ACli NG DIRECTOR NAIIOH-L CLI "A liC CENtER 1 71 ( .· c:x: ;;_.:, z t-1-Uw ow ::::.c:::: _J ( ~­ \ .. :-- c:x: 1- OC I 1982 ISS N 01~8 -0 42 4 I ALKEE I NA , ILA Sl A I I LKEEIN I IIRPOR I LOCAL CLIMATOLOGICAL DATA MEA S'C CQ NIR ACI ~E I 08ST Monthly Summary Lll I IUD£ &2° 18. N LON&IIUO E I S0° 0&' M lift£ 101£ a t i SKU OE&AH OU S W(UH(A I!P[S Sl OW UUUE WIN O I U CO ,EA I ("P(RAI UR[ °F BASE &S0 f IC E PR(CI PII U IO N SI I IIOI '" P H I SU NSH I N( I ![NIH SI 1 ro& PEllE IS PA[SIUR( I -2 H[AYI fOG OR ~ II C> ••~rE_sr I I ... -~ . ~ 5::~ ~~ l IHU NO[AI I OAR IC E ON " ':: I ~CII(S <X C> ~I L' .z; -... ~ ;~ I IC( PEl lE'S &AOUI O c C> "' --c ~ Q. ... _., -"' ~"' I Mi ll II (LEV --"' z C>"' "' <X"" ~ -'i ~.;; z ! 0 0 ... x z ., ~ ~ ::>0 ~-"' ... & GL I Z£ 0 81ft -~ J S& c ~ -"' -... ~"' => "' -z "'-"'"' ... ., --~ -~ z "'"' "'= "' "' c <X c"' -.. -.. 1 OUS ISIOAft '"'% ~~ FEEl ~ ;; C> ~ -~~ -=> --~ --<X co:: "' ... ::> ~ ~ => ~c <X "' "'"' ~ ... 0 I SftOLl. 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