Flood Potential Outlook
Issued by NWS Seattle/Tacoma, WA

000
FGUS76 KSEW 292212
ESFSEW
WAC009-015-027>35-041-045-053>061-067-073-312300-

WATER SUPPLY OUTLOOK
NATIONAL WEATHER SERVICE SEATTLE WA
310 PM PDT FRI MAR 29 2013

...WESTERN WASHINGTON WATER SUPPLY OUTLOOK...

SYNOPSIS: THE FORECASTS OF WATER SUPPLY FOR THE SUMMER IN WESTERN
WASHINGTON WERE MOSTLY FOR NEAR NORMAL VOLUMES FOR WASHINGTON RIVERS.
BUT THERE WAS A SPREAD FROM SLIGHTLY BELOW NORMAL TO SLIGHTLY ABOVE
NORMAL.


PRECIPITATION SUMMARY
---------------------

THE FIRST PART OF 2013 CONTINUED TO BE DRIER THAN USUAL WITH ALL OF
WASHINGTON STATE REPORTING BELOW NORMAL PRECIPITATION FOR FEBRUARY.
HOWEVER...MUCH OF THE STATE IS STILL AT OR ABOVE NORMAL FOR
THE WATER YEAR.

THE MONTHLY PERCENTAGE OF NORMAL FOR PRECIPITATION RANGED FROM 58
PERCENT FOR THE PUGET SOUND LOWLANDS TO 89 PERCENT OVER THE COAST.
THE GREATEST AMOUNT OF PRECIPITATION AT THE CLIMATE STATIONS FOR THE
MOUNTAINS...COAST...AND INTERIOR LOWLANDS WAS 11.80 INCHES AT THE
HOH RANGER STATION IN THE OLYMPICS...11.77 INCHES AT QUILLAYUTE...
AND 8.82 INCHES AT GRAYS RIVER.

SNOWPACK SUMMARY
----------------

THE SNOWPACK WAS ABOVE NORMAL FOR WESTERN WASHINGTON AS OF MARCH 25.
THE WATER CONTENT OF THE  MOUNTAIN SNOWPACK IN THE BASINS THAT FEED
THE MAJOR RIVERS WEST OF THE CASCADES RANGED FROM 115 TO 141 PERCENT
OF NORMAL.

DATA FROM THE NORTHWEST WEATHER AND AVALANCHE CENTER AS OF MARCH 15
SHOWED THAT SNOW DEPTHS IN WESTERN WASHINGTON WERE 80 TO 105
PERCENT OF NORMAL. THAT WAS BEFORE A BUNCH OF SNOW THAT WAS RECEIVED
IN THE WINTER AT THE END OF LAST WEEK.


STREAMFLOWS SUMMARY
-------------------

STREAMFLOWS FOR LAST MONTH WERE BELOW TO NEAR NORMAL FOR MOST OF
WESTERN WASHINGTON RIVERS.


RESERVOIR STORAGE SUMMARY
-------------------------

STORAGE FOR MAJOR RESERVOIRS AROUND THE WESTERN WASHINGTON WERE
BELOW NORMAL AS OF THE FIRST OF MARCH. NOTE THAT DURING THE WINTER
MOST RESERVOIRS ARE KEPT RELATIVELY LOW UNTIL THE SPRING RUNOFF AND
STORAGE LEVELS ARE NOT INDICATIVE OF FUTURE WATER AVAILABILITY.


WEATHER OUTLOOK
---------------

THE OUTLOOK FOR MARCH AND BEYOND...FOR THE NEXT TWO WEEKS THE
OUTLOOK IS FOR BELOW NORMAL PRECIPITATION. THE THREE MONTH OUTLOOK
BEGINNING IN MARCH AND ENDING IN MAY CALLS FOR EQUAL CHANCES OF
ABOVE OR BELOW NORMAL PRECIPITATION FOR MOST OF WASHINGTON.


WATER SUPPLY OUTLOOK
--------------------

LONG RANGE HYDROLOGIC MODELS WERE FORECASTING A SPREAD OF BELOW
NORMAL TO ABOVE NORMAL RIVER FLOWS AND WATER SUPPLY FOR MOST RIVERS
THROUGH THIS SPRING AND SUMMER. MOST RIVERS HAVE FORECASTS OF NEAR
NORMAL FLOWS. THE EXCEPTIONS ARE THE CEDAR RIVER WITH A FORECAST FOR
ABOVE NORMAL FLOW AND THE TOLT AND NISQUALLY WHICH ARE FORECAST FOR
BELOW NORMAL FLOWS. WATER SUPPLY FORECASTS FOR WESTERN WASHINGTON
RANGED FROM A LOW OF 85 FOR THE TOLT RIVER TO 118 PERCENT OF NORMAL
FOR THE CEDAR RIVER. WATER SUPPLY FORECASTS THAT INCLUDE REGULATION
ARE USED FOR LOCATIONS WHERE FORECASTS ARE LISTED BELOW AS
REGULATED...FOR ALL OTHER LOCATIONS FORECASTS ARE FOR NATURAL
VOLUMES.

HERE ARE THE STREAM FLOW VOLUME FORECASTS FOR SPECIFIC RIVERS AND
SITES AS OF MARCH 25.

                           WATER SUPPLY FORECASTS
                  NATURAL FLOW UNLESS OTHERWISE SPECIFIED
                        (IN THOUSANDS OF ACRE FEET)

RIVER AND GAUGING SITE            PERIOD   FORECAST   NORMAL  PERCENT

SKAGIT RIVER
   NEAR CONCRETE (REGULATED)      APR-SEP      6504     5934     110

BAKER RIVER
   UPPER BAKER RESERVOIR INFLOW   APR-SEP      1130     0063     105

SULTAN RIVER
   SPADA LAKE INFLOW              APR-SEP       179      190      94

TOLT RIVER
   TOLT RESERVOIR INFLOW          APR-SEP       176      206      85

CEDAR RIVER
   CHESTER MORSE LAKE INFLOW      APR-SEP       296      249     118

NISQUALLY RIVER
   ALDER RESERVOIR INFLOW         APR-SEP       351      409      86

COWLITZ RIVER
   MAYFIELD RESERVOIR (REGULATED) APR-SEP      1974     1835     108

ELWHA RIVER
   MCDONALD BRIDGE                APR-SEP       512      556      92

DUNGENESS RIVER
   NEAR SEQUIM                    APR-SEP       146      145     101

WYNOOCHEE RIVER
   WYNOOCHEE DAM INFLOW           APR-SEP       104      101     105

SKOKOMISH RIVER
   CUSHMAN DAM INFLOW             APR-SEP       233      221     105


THESE FORECASTS ARE SELECTED FROM THOSE PREPARED BY THE NWRFC.
FOR FURTHER DETAILS...GRAPHICS...AND STATISTICS REGARDING THE WATER
SUPPLY FORECASTS VISIT:
HTTP://WWW.NWRFC.NOAA.GOV/WS (LOWER CASE)
HTTP://WWW.NWRFC.NOAA.GOV/OUTLOOK (LOWER CASE)


THE NEXT WATER SUPPLY OUTLOOK FOR WASHINGTON WILL BE ISSUED THE
FIRST PART OF APRIL.

$$

WEATHER.GOV/SEATTLE
JBB