HYDROLOGIC OUTLOOK Issue Date: 439 AM PST WED NOV 25 2009 Expiration: 445 PM PST WED NOV 25 2009 ...RAINFALL OVER WESTERN WASHINGTON LATER TODAY THROUGH THURSDAY
NIGHT COULD PUSH THE MOST-FLOOD PRONE RIVERS ABOVE FLOOD STAGE...
A FRONT WILL MOVE INTO WESTERN WASHINGTON TODAY AND REMAIN STALLED
OVER THE AREA TONIGHT...THANKSGIVING DAY...AND INTO THURSDAY
NIGHT. THIS COULD PRODUCE ENOUGH RAIN TO CAUSE FLOODING ON THE
MOST FLOOD-PRONE RIVER REACHES IN THE AREA.
THIS INCLUDES...BUT IS NOT NECESSARILY LIMITED TO...THE SKOKOMISH
RIVER IN MASON COUNTY...THE SNOQUALMIE RIVER NEAR CARNATION IN
KING COUNTY...THE PUYALLUP RIVER NEAR ORTING IN PIERCE COUNTY...
AND THE LOWER REACH OF THE CHEHALIS RIVER IN THURSTON AND GRAYS
HARBOR COUNTIES.
IF FLOODING DOES OCCUR...IT WILL LIKELY BE MINOR WITH THE POSSIBLE
EXCEPTION OF THE SKOKOMISH RIVER.
FLOODING COULD BEGIN ON THE SKOKOMISH RIVER THURSDAY OR THURSDAY
NIGHT. IF FLOODING OCCURS ON THE SNOQUALMIE OR PUYALLUP RIVERS...
WHICH FLOW OUT OF THE CASCADES...IT WOULD PROBABLY START THURSDAY
NIGHT OR FRIDAY. THE LOWER REACH OF THE CHEHALIS RIVER...WHICH
DRAINS A LARGE AREA OF SOUTHWEST WASHINGTON...WOULD NOT BEGIN
UNTIL FRIDAY NIGHT OR SATURDAY.
RAINFALL TOTALS OF 2 TO 4 INCHES ARE LIKELY OVER THE OLYMPIC
PENINSULA WITH ONE AND A HALF TO 3 INCHES LIKELY OVER THE
CASCADES. THE SNOW LEVEL WILL BE AROUND 8000 FEET TODAY AND
GRADUALLY FALL TO 5500 FEET THURSDAY NIGHT.
RIVERS THROUGHOUT WESTERN WASHINGTON ARE RUNNING HIGHER THAN
NORMAL DUE TO UNUSUALLY WET WEATHER OVER THE PAST MONTH. THEREFORE
THE RAINFALL EXPECTED...WHILE NOT EXCEPTIONAL...COULD BE ENOUGH TO
DRIVE THE MOST FLOOD-PRONE SPOTS ABOVE FLOOD STAGE.
FLOODING IS NOT EXPECTED ON THE GREEN RIVER.
$$
MCDONNAL
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