FGUS76 KSEW DDHHMM ESFSEW WAC009-027-029-031-033-035-041-045-053-055-057-061-067-073-302300- HYDROLOGIC OUTLOOK NATIONAL WEATHER SERVICE SEATTLE WA 1115 AM PDT THU JUN 19 2008 ...WASHINGTON WATER SUPPLY OUTLOOK... THE FORECASTS OF WATER SUPPLY FOR THE SUMMER IN WASHINGTON ARE FOR NORMAL TO ABOVE NORMAL AMOUNTS FOR MOST WASHINGTON RIVERS. THE FORECAST FOR THE COLUMBIA RIVER AT THE DALLES WAS FOR 99 PERCENT OF NORMAL. FORECASTS THIS MONTH WERE FOR GENERALLY HIGHER AMOUNTS THAN THEY WERE LAST MONTH FOR MOST RIVERS ON THE EAST SIDE. INCREASES WERE ONLY A FEW PERCENT A FEW PERCENT FOR THE LARGER RIVERS BUT UP TO TEN PERCENT FOR SOME OF THE SMALLER ONES OFF THE EAST SIDE OF THE CASCADES. THERE WERE DECREASES IN THE FORECASTS FOR MOST WESTERN WASHINGTON RIVERS. PRECIPITATION SUMMARY --------------------- MAY WAS A VERY DRY MONTH FOR MOST OF WASHINGTON WITH MUCH BELOW NORMAL PRECIPITATION. FOR WESTERN WASHINGTON...THE PERCENTAGE OF NORMAL PRECIPITATION RANGED FROM 38 FOR THE OLYMPICS TO 96 FOR THE NORTHWEST INTERIOR. FOR EASTERN WASHINGTON...THE PERCENTAGE OF NORMAL PRECIPITATION RANGED FROM 30 FOR THE OKANOGAN TO 95 FOR THE PALOUSE AND BLUE MOUNTAINS. SNOWPACK SUMMARY ---------------- HE SNOWPACK WAS ABOVE NORMAL FOR MOST OF WASHINGTON AS OF JUNE 18. THE WATER CONTENT OF THE MOUNTAIN SNOWPACK IN THE BASINS THAT FEED THE MAJOR RIVERS EAST OF THE CASCADES CREST RANGED FROM 100 TO 361 PERCENT OF NORMAL. WEST OF THE CASCADES...THE WATER CONTENT OF THE SNOWPACK RANGED FROM 195 TO 582 PERCENT OF NORMAL. THE OLYMPICS STILL SHOWED UP TO 27 INCHES OF SNOW WATER EQUIVALENT WHEN BY THIS DATE THERE SHOULD BE NEARLY ZERO INCHES. STREAMFLOWS SUMMARY ------------------ STREAMFLOWS WERE ABOVE NORMAL FOR MOST OF WASHINGTON RIVERS AS OF JUNE 18. WEATHER OUTLOOK --------------- THE OUTLOOK FOR JUNE AND BEYOND...EQUAL CHANCES OF ABOVE NORMAL... NORMAL...OR BELOW NORM PRECIPITATION. THE OUTLOOK FOR THE PERIOD JUNE THROUGH AUGUST IS FOR SLIGHTLY INCREASED CHANCE OF BELOW NORMAL PRECIPITATION. WATER SUPPLY OUTLOOK -------------------- LONG RANGE HYDROLOGIC MODELS WERE FORECASTING NEAR NORMAL TO ABOVE NORMAL RIVER FLOWS AND WATER SUPPLY FOR MOST RIVERS THROUGH THIS SPRING AND SUMMER. THE FORECASTS FOR EASTERN WASHINGTON RANGED FROM AROUND 90 TO 125 PERCENT OF NORMAL. THE OKANOGAN RIVER BASIN HAD THE LOWEST AMOUNT FORECAST AT 93 PERCENT OF NORMAL. THE YAKIMA... NACHES...AND SPOKANE RIVERS HAD THE HIGHEST AMOUNT FORECAST AT AROUND 121 TO 123 PERCENT OF NORMAL. WATER SUPPLY FORECASTS FOR WESTERN WASHINGTON WERE FROM 97 TO 118 PERCENT OF NORMAL. FORECASTS ASSUMED 90 PERCENT OF NORMAL PRECIPITATION FOR THE FIRST HALF OF JUNE THEN CLIMATIC CONDITIONS DURING THE REST OF THE FORECAST PERIOD. HERE ARE THE STREAM FLOW VOLUME FORECASTS FOR SPECIFIC RIVERS AND SITES AS OF JUNE 8 WATER SUPPLY FORECASTS (IN THOUSANDS OF ACRE FEET) RIVER AND GAUGING SITE PERIOD FORECAST NORMAL PERCENT COLUMBIA RIVER AT GRAND COULEE DAM JAN-JUL 59800 62900 95 APR-SEP 63500 63990 99 BELOW ROCK ISLAND DAM APR-SEP 66400 69540 96 NEAR THE DALLES JAN-JUL 98200 107300 92 APR-SEP 97400 97300 99 PEND OREILLE RIVER PEND OREILLE LAKE INFLOW APR-SEP 14500 13910 104 COUER D'ALENE RIVER COUER D'ALENE LAKE INFLOW APR-JUL 3110 2552 122 OKANOGAN RIVER NEAR TONASKET APR-SEP 1640 1766 93 SIMILKAMEEN RIVER NEAR NIGHTHAWK APR-JUL 1280 1350 95 CHELAN RIVER LAKE CHELAN INFLOW APR-SEP 1220 1185 103 WENATCHEE RIVER AT PESHASTIN APR-SEP 1640 1635 100 YAKIMA RIVER NEAR PARKER APR-SEP 2360 1918 123 SNAKE RIVER LOWER GRANITE RSVR INFLOW JAN-JUL 26600 30020 89 APR-JUL 21900 21550 102 SOUTH FORK WALLA WALLA RIVER NEAR MILTON APR-JUL 90 53 170 SKAGIT RIVER NEAR CONCRETE APR-SEP 6630 6365 104 COWLITZ RIVER MAYFIELD RESERVOIR INFLOW APR-JUL 1940 1689 115 APR-SEP 2210 1922 115 AT CASTLE ROCK APR-SEP 2900 2639 110 DUNGENESS RIVER NEAR SEQUIM APR-SEP 180 152 118 THESE FORECASTS ARE SELECTED FROM THOSE PREPARED BY: NATIONAL WEATHER SERVICE...NATURAL RESOURCE CONSERVATION SERVICER...AND B.C. HYDRO AND POWER AUTHORITY. FOR VARIOUS PROJECT INFLOWS...THE FORECASTS HAVE BEEN COORDINATED WITH THE U.S. ARMY CORP OF ENGINEERS AND THE U.S. BUREAU OF RECLAMATION. FOR FURTHER DETAILS ON THE WATER SUPPLY FORECAST VISIT HTTP://WWW.NWRFC.NOAA.GOV/WATER_SUPPLY/WS_FCST.CGI (LOWER CASE). THE NEXT WATER SUPPLY OUTLOOK FOR WASHINGTON WILL BE ISSUED AROUND JULY 8 $$ JBB WEATHER.GOV/SEATTLE