Table Of Content

Historic, Archive Document Do not assume content reflects current scientific knowledge, policies, or practices. { I i I i} ’ i >v" i i J I i i I 1 ? ( i^Ocfuijy jited States ipartment of Washington ^riculture Natural Resources Conservation Basin Outlook Service June 2000 c: S 1 , Basin Outlook Reports and Federal - State - Private Snow Cooperative Surveys Formore watersupply and resource management information, contact: Local Natural Resources Conservation Service Field Office or or ScottPattee BettySchmitt WaterSuppiySpecialist PublicAffairs Speciaiist Natural Resources Conservation Service Natural Resources Conservation Service 2021 E. CollegeWay, Suite 214 316W. BooneAve., Suite450 Mt Vernon, WA 98273-2873 Spokane, WA 99201-2348 (360)428-7684 (509) 323-2912 Howforecasts are made Most ofthe annual streamflow in the western United States originates as snowfall thathas accumulated in the mountains during thewinter and early spring. As the snowpack accumulates, hydrologists estimate the runoffthatwill occurwhen it melts. Measurements ofsnow water equivalent at selected manual snow courses and automated SNOTEL sites, along withprecipitation, antecedent streamflow, and indices ofthe El Nino / Southern Oscillation are used in computerized statistical and simulation models toprepare runoffforecasts. These forecasts are coordinated between hydrologists inthe Natural Resources Conservation Service and the National Weather Service. Unless otherwise specified, all forecasts are for flows that would occurnaturally without any upstream influences. Forecasts ofanykind, ofcourse, are not perfect. Streamflow forecast uncertainty arises from three primary sources: (1) uncertain knowledge offuture weather conditions, (2) uncertainty in the forecastingprocedure, and (3) errors in the data. The forecast, therefore, mustbe interpreted not as a single value but rather as a range ofvalues with specific probabilities ofoccurrence. The middle ofthe range is expressed by the 50% exceedanceprobability forecast, for whichthere is a 50% chancethatthe actual flow will be above, and a 50% chance thatthe actual flow will be below, this value. To describe the expected range around this 50% value, four other forecasts are provided, two smaller values (90% and 70% exceedanceprobability) and two largervalues (30%, and 10% exceedance probability). For example, there is a90% chance thatthe actual flow will be more than the 90% exceedance probability forecast. The others can be interpreted similarly. The widerthe spread among these values, the more uncertain the forecast. As the seasonprogresses, forecasts become more accurate, primarily because a greaterportion ofthe future weather conditions become known; this is reflectedby a narrowing ofthe range around the 50% exceedance probability forecast. Users should take this uncertainty into consideration when making operational decisions by selecting forecasts corresponding to the level ofrisk they are willing to assume about the amount ofwaterto be expected. Ifusers anticipate receiving a lesser supply ofwater, or iftheywish to increasetheir chances ofhaving an adequate supply ofwater fortheir operations, they may want to base their decisions on the 90% or 70% exceedanceprobability forecasts, or something in between. On the otherhand, ifusers are concerned aboutreceiving too much water (for example, threat offlooding), they may want to base their decisions on the 30% or 10% exceedanceprobability forecasts, or something in between. Regardless ofthe forecastvalue users choose for operations, they should beprepared to deal with either more or less water. (Users should remember that even ifthe 90% exceedanceprobability forecast is used, there is still a 10% chance ofreceiving less than this amount.) By using the exceedanceprobability information, users can easily determine the chances ofreceiving more or less water. TheU.S. DepartmentofAgriculture(USDA) prohibitsdiscrimination inall itsprogramsandactivitiesonthebasisofrace, color, nationalorigin, gender, religion, age, disability, political beliefs, sexualorientation, and maritalorfamilialstatus. (Notallprohibited basesapplytoall programs.) Personswith disabilitieswhorequirealternativemeansforcommunicationofprogram information (Braille, largeprint, audiotape, etc.) should contactUSDA’sTARGET Centerat(202)720-2600(voiceandTDD). Tofileacomplaintofdiscrimination, writeUSDA, Director, OfficeofCivil Rights, Room326W,Whitten Building, 14thand IndependenceAvenue, SW, Washington, D.C., 20250-9410, orcall (202)270-5964(voiceorTDD). USDA isanequalopportunityemployer. .. ... Washington Water Supply Outlook June 2000 General Outlook The month ofMay was considerably wetter and cooler than the previous month. These conditions helped slow upper elevation snow melt and are the reason for reported increases in snow-water-content in many basins. Every telemetered site in Washington is loosing snowpack, however many ended the season with above average accumulations and is melting slower than normal. The Snow Survey staff, in cooperation with Asotin County and Seattle City Light, is planning for the installation offournew SNOTEL sites in Washington this summer. These new sites will be used for improving streamflow forecasting, resource management and early flood warning. Also, please take a look at the Glacier Research Page (colored insert) at the back ofthis report. Snowpack The June 1 statewide SNOTEL readings remained above average at 1 1 1%. Cooler temperatures have helped curtail a rapid spring melt. Among the basins withremaining measurable snowpack the Walla Walla River Basin reported the lowest readings at 36% ofaverage. Readings taken in the Lewis River Basin reported the highest at 422% ofaverage. Westside averages from SNOTEL and June 1 snow surveys included the North Puget Sound riverbasins with 84%, the Central Puget riverbasins with 161%, and the Olympic basins with 73%. Snowpack along the east slopes ofthe Cascade Mountains included the Yakima area with 137% and the Wenatchee area with 104%. Snowpack in the Spokane River Basin was at 61% and the Pend Oreille River Basin, including Canadian data, had 56% ofaverage. Maximum snow cover in Washington was at Paradise Park SNOTEL near Mount Rainer with a water content of78.1 inches. This site would normally have 48.1 inches ofwater content on June 1. Last year at this time Paradise Parkhad 106.7 inches ofsnow water. BASIN PERCENT OF PERCENT OF ONE MONTH LAST YEAR AVERAGE CHANGE Spokane 43 61 -23 . . . Newman Lake 00 00 00 . . . Pend Oreille 39 56 -17 . . . Okanogan 60 120 38 . . . Methow 39 89 6 . . Wenatchee 38 94 -3 . . . Chelan 48 114 11 . . . Stemilt Creek 00 00 00 . . . . . . Yakima 35 137 30 . . . Ahtanum Creek 00 00 00 . . . . . . Walla Walla 15 36 -42 . . Lower Snake 31 54 -29 . . . Cowlitz 48 140 21 . . . Lewis 41 422 238 . . . White 46 159 46 . . . Green 40 165 26 . . . Puyallup 46 159 46 . . . Cedar 00 00 00 . . . Snoqualmie 52 153 45 . . . Skykomish 51 151 46 . . . Skagit 40 93 10 . . . Baker N/A N/A N/A . . Nooksack 25 75 ... -24 . Olympic Peninsula 16 73 ... -9 Precipitation During the month ofMay, the National Weather Service andNatural Resources Conservation Service climate stations showed a wide variation in average precipitation across the state. The highestpercent ofaverage in the state was at Glenwood in Klickitat County. Glenwoodreported 257% ofaverage for a total of 1.9 inches. The average for this site is .74 inches for May. Averages for the water year varied from 118% ofaverage in the Walla Walla River Basin to 89% ofaverage in the Okanogan - Methowriver basins. RIVER MAY WATER YEAR ONE MONTH BASIN PERCENT OF AVERAGE PERCENT OF AVERAGE CHANGE Spokane 105 111 -2 Colville-Pend Oreille 124 108 1 Okanogan-Methow 71 89 -2 Wenatchee-Chelan 113 103 -0 Upper Yakima 114 104 -0 Lower Yakima 94 112 -1 Walla Walla 168 118 2 Lower Snake 79 101 -2 Cowlitz-Lewis 113 107 -1 White-Green-Puyallup 125 99 3 Central Puget Sound 133 110 1 North Puget Sound 137 104 1 Olympic Peninsula 146 111 2 Reservoir Reservoir storage in the Yakima Basin was 804,200-acre feet, 109% ofaverage for the Upper Reaches and 227,800-acre feet, 117% ofaverage for Rimrock and Bumping Lakes. Storage at the Okanogan reservoirs was 1 15% ofaverage for June 1. The power generation reservoirs included the following: Coeur d’Alene Lake, 215,500-acre feet, 77% ofaverage and 90% ofcapacity; Chelan Lake, 457,800-acre feet, 102% ofaverage and 68% ofcapacity; and Ross Lake at 94% ofaverage and 69% ofcapacity. BASIN PERCENT OF CAPACITY PERCENT OF AVERAGE Spokane 90 77 . . . . Colville-Pend Oreille 47 85 . . . . Okanogan-Methow 88 115 . . . . Wenatchee-Chelan 68 102 . . . . Upper Yakima 96 109 . . . . Lower Yakima 98 117 . . . . North Puget Sound 71 95 . . . . Formore informatioii contactyourlocalNaturalResources Consei-vation Service office. 2 Streamflow June forecasts indicate nearnormal summer flows for most streams in the state. They vary from 123% ofaverage for Klickitat River near Glenwood to 70% ofaverage for Grande Ronde River at Troy. June forecasts for some Western Washington streams include the Cedar River near Cedar Falls, 94%; Green River, 100%; and Skagit River, 87%. Some Eastern Washington streams include the Yakima River near Parker, 92%; Wenatchee River at Plain, 99%; and Spokane River near Post Falls, 80%. Volumetric forecasts are developed using current, historic and average snowpack, precipitation, streamflow and SOI data collected and coordinated by organizations cooperating with NRCS. Streamflows reported for May were near to slightlybelow average. The Lewis Rivernear Ariel had the highest flows with 224% ofaverage. The Methow at Pateros with 77% ofaverage, was the lowest in the state. Other streamflows were the following percentage ofaverage: the Priest River, 105%; the Columbia at The Dalles, 89%; the Spokane at Spokane, 82%; the Columbia below Rock Island Dam, 92%; the Cowlitz at Castle Rock, 94%; and the Snake Riverbelow Ice Harbor Dam, 82%. BASIN PERCENT OF AVERAGE MOST PROBABLE FORECAST (50 PERCENT CHANCE OF EXCEEDENCE) Spokane 80-83 Colville-Pend Oreille 79-119 Okanogan-Methow 84-100 Wenatchee-Chelan 96-109 Upper Yakima 87-90 Lower Yakima 87-123 Walla Walla 100-105 Lower Snake 70-77 Cowlitz-Lewis 92-128 White-Green-Puyallup 96-100 Central Puget Sound 91-101 North Puget Sound 87-97 Olympic Peninsula 93-98 STREAM PERCENT OF AVERAGE MAY STREAMFLOWS Pend Oreille Below Box Canyon 91 Kettle at Laurier 95 Columbia at Birchbank 91 Spokane at Long Lake 95 Similkameen at Nighthawk 83 Okanogan at Tonasket 92 Methow at Pateros 77 Chelan at Chelan 86 Wenatchee at Pashastin 92 Yakima at Cle Elum 100 Yakima at Parker 90 Naches at Naches 87 Grande Ronde at Troy 83 Snake below Lower Granite Dam 84 SF Walla Walla near Milton Freewater 81 Lewis at Ariel 224 Cowlitz below Mayfield Dam 92 Skagit at Concrete 96 Foi'more information contactyourlocalNaturalResources Conservation Serx'iceoffice. 3 8606898 6 8 26 6 BASIN SUMMARY OF SNOW COURSE DATA JUNE 2000 DATE SNOW WATER LAST AVERAGE SNOW COCTRSE ELEVATION DATE SNOW WATER LAST AVERAGE DEPTH CONTENT YEAR 1961-90 DEPTH CONTENT YEAR 1961-9C — 7368159280050000 6666////00001111////00000000 ——— 41221....7761 4316535....405 2122004....7709 MMMMTOOO.SSUEQNSUTKIOTBMCOATRUNAGRDG PPPIIICLLLALLLNOOO.WWW 4455802505000000 6665////00021118////00000000 ——114 1111,...8620 2116071....2902 165....0000 2200 5/30/00 0 .0 3. MOUNT GARDNER PILLOW 2860 6/01/00 — .0 .1 .0 365675851000 565///320061///000000 —152968 12379...032 415007...2 427..1 NNN.EEFZW.HPOEELZRKCOEMECERCNMPPLIAPLKILELOLWOW 625286505000 656///030101///000000 ——0 ...500 ...000 ..92 7100 6/01/00 .3 .0 2.4 NOISY BASIN PILLOW 6040 6/01/00 25.8 34.8 30.2 44247500 66//0011//0000 —0 ..00 -.-0 -.-0 NOOLRATLHLIEFORMKDWSJOCKPOILLOW 63936300 66//0011//0000 ——36 1376..61 3831..29 2360..30 46600000 66//0011//0000 ——94 1429..40 9421..7 6.3 PPAARRKADICSKERIPDAGREK PPIILLLLOOWW 45650000 66//0011//0000 —21 7118..71 10468..72 485..12 5000 6/01/00 12.9 31.5 15.4 PETERSON MDW PILLOW 7200 6/01/00 .2 5.2 2.7 463555002762600800000000 566666//////300000111111//////000000000000 ————00 28......800000 4192......30000 19......600000 PPPPQRIOUIOAKPAGTIEERTANTATYZIOCRLIRPDEHAPGEISEPEKSLAELKAKPILPLPPPPOIIIIIWLLLLLLLLLLOOOOOWWWWW 345544579957400308000000 666666//////000000111111//////000000000000 ————880 31086......60800 714239364...,..482098 327701......594100 5900 6/01/00 61 33.4 62.8 31.8 REX RIVER PILLOW 1900 6/01/00 —6 1.6 21.2 .0 73025000 65//0310//0000 —250 12..10 451..66 46..12 RSOACDDKLEER MPTENAKPPIILLLOLWOW 78900000 66//0011//0000 —— 32..78 1220..47 1137..25 4350 6/01/00 .0 .0 .0 SALMON MDWS PILLOW 4500 6/01/00 — .0 .0 .0 5800 5/28/00 1—04 50.4 55.5 38.9 SASSE RIDGE PILLOW 4200 6/01/00 — 2.8 35.0 1.3 3370 6/01/00 — 3.3 27,5 5.0 SAVAGE PASS PILLOW 6170 6/01/00 — .0 18.1 12.5 6300 6/01/00 30.9 52.7 34.4 SHEEP CANYON PILLOW 4050 6/01/00 26.5 68.4 11.6 3500 5/30/00 —0 .0 6.0 SILVER STAR MTN CAN. 5600 5/29/00 —54 28.1 35.7 16.1 466304008000 666///000111///000000 ——— ...300 21...600 13...820 SSSPKKEAONLOCKKEAURHMOMCDRPWEIELKLOWPPIILLLLOOWW 733294620000 666///000111///000000 ——— 44...220 124826...896 15...800 556305830000 666///000111///000000 —— 22...500 613...320 25...300 SSSTPTAIAHRMLIPTEDPEELAAKKPEASPSILLPPOIIWLLLLOOWW 363108036000 666///000111///000000 ——— 2234...770 4409.,.060 2175...300 5770 6/01/00 24 11.4 19.6 11.2 STEVENS PASS PILLOW 4070 6/01/00 7.4 31.8 5.7 4850 5/30/00 —0 .0 16.0 2.4 STEVENS PASS SAND SD 3700 5/30/00 7 3.8 28,7 9.7 4980 6/01/00 — 1.4 .0 .6 STRYKER BASIN 6180 5/31/00 31 15.2 31.0 20.6 6050 6/01/00 — 20.4 49.3 29,2 STUART MOUNTAIN 7400 6/01/00 —20 8.2 -- -- 434535227281505404000000 666666//////000000111111//////000000000000 —————— 32096......621000 17265920......76600 109....,.040000 TTTTSSRHIOUUOUNURNUNKCPSGDRHHEHEITAESRMTE#2BC#2RALKESSEIKN PPPPPIIIIILLLLLLLLLLOOOOOWWWWW 443555205253003541000000 665666//////003000110111//////000000000000 ————20 3771.....,436001 3614589.....,84200 1112406......550000 5000 6/01/00 — .0 3.5 .0 TV MOUNTAIN 6800 6/01/00 —2 .5 -- -- 6110 6/01/00 — 33.8 58.5 46.8 TWELVEMILE PILLOW 5600 6/01/00 — .0 .0 .6 45698000 66//0011//0000 — 51..21 86..20 43..30 TUPWPIENRLWAHKEESELEPRILLPOIWLLOW 64440000 66//0011//0000 —— 6..30 36..00 25,.80 413792504000 566///300011///000000 ——0 ...000 18...950 --.--0 WWWHAEILRTLMESSPCPRRAISESNEGKSESPPIPILILLLOLLWOOWW 744825000000 666///000111///000000 —— 1029...511 142900...06 12924...62 6200 6/01/00 .0 .0 .0 WHITE ROCKS MTN CAN. 7200 6/01/00 11 9.3 6.6 5400 6/01/00 ,-- 36.2 92.3 21.4 4 : : :: : i^NRCS Natural Resources Conservation Service Washington State Snow, Water and Climate Services Leonard Jordan Scott Pattee State Conservationist Water Supply Specialist W. 316 Boone Ave Suite 450 2021 E. College Way, Suite 214 . , Spokane, WA 99201-2348 Mount Vernon, WA 98273-2873 phone: 509-323-2961 phone: 360-428-7684 fax: 509-323-2979 fax: 360-424-6172 leonard [email protected] [email protected] .i Betty Schmitt Chris Pacheco Public Affairs Specialist Resource Conservationist W. 316 Boone Ave., Suite 450 National Water and Climate Center Spokane, WA 99201-2348 101 SW Main St., Suite 1600 phone: 509-323-2912 Portland, OR 97204-3224 fax: 509-323-2909 phone: 503-414-3056 [email protected] fax: 503-414-3101 [email protected] SaiSlii? NRCS Snow Survey and Climate Services Homepages Washington http://www.wa.nrcs.usda.gov/snow/snow.htm Oregon http://crvstalor.nrcs.usda.gov/snowsurveys Idaho http://idsnow.id.m-cs.usda.gov National Water and Climate Center (NWCC) http://www.wcc.nrcs.usda.gov NWCC Anonymous FTP Server: ftp.wcc.nrcs.usda.gov USDA-NRCS Agency Homepages Washington http://www.wa.iircs.usda.gov/nrcs NRCS National: http://www.ftw.nrcs.usda.gov 5 i^NRCS Natural Resources Conservation Service Washington State Snow, Water and Climate Services ::Field Office Eastern Washington Jimmie Gleaton Doug Allen District Conservationist District Conservationist 232 Williams Lake Road 301 Yakima Street, Room 301 WA WA Colville, 99114-9638 Wenatchee, 98801-2966 509-685-0937 509-664-0265 [email protected] [email protected] Randy Kelley David Chain District Conservationist District Conservationist 1251 Second Ave. South, Room 101 607 E. Mountain View WA WA Okanogan, 98840-9723 Ellensburg, 98926 509-422-2750 509-925-8585 [email protected] [email protected] Western Washington John Gillies Kerry Perkins District Conservationist District Conservationist 6975 HamWieAgen Road 1 1 1 East 3rd, RWoAom 2B Lynden, 98205-1535 Port Angeles, 98362-3009 360-354-2035 360-457-5091 [email protected] [email protected] Monica Hoover Scott Pattee Wetland Specialist Water Supply Specialist 1835 Black Lake Blvd SW, STE E 2021 E. College Way, Suite 214 WA WA Olympia, 98512-5623 Mount Vernon, 98273-2873 360-704-7752 360-428-7684 [email protected] [email protected] ^ -V “ r ^Data Collection.Offices : Jon Lea Ron Abramovich Oregon Data Collection Office Idaho Data Collection Office 101 SW Main St., Suite 1300 9173 West Barnes, Suite C Portland, OR 97204 Boise, ID 83709 503-414-3267 208-378-5741 ilea(gjor.usda.gov [email protected] 6