127
FGUS76 KSEW 191817
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
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