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000
FXUS66 KSEW 082324
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 PM PST SAT MAR 8 2014

.SYNOPSIS...A STRONG FRONTAL SYSTEM WILL AFFECT WESTERN WASHINGTON
TONIGHT WITH HEAVY RAIN...HIGH SNOW LEVELS...AND LOCALLY WINDY
CONDITIONS. AN UPPER TROUGH WILL MOVE THROUGH ON MONDAY FOR COOLER
SHOWERY WEATHER. A STRONG UPPER RIDGE WILL PROVIDE DRY AND MILD
WEATHER TUESDAY THROUGH THURSDAY.

&&

.SHORT TERM...A WET PACIFIC FRONTAL SYSTEM WILL CONTINUE TO SPREAD
MORE RAIN THROUGH WESTERN WA TONIGHT...RAIN WILL BE HEAVY AT
TIMES. THIS SYSTEM HAS REMNANTS OF TYPHOON FAXAI EMBEDDED IN THE
FLOW AND LOOKS FAIRLY JUICY ON SATELLITE...WITH A PLUME OF MOISTURE
STRETCHING WELL OFFSHORE. ALL THIS MOISTURE WILL TRAIN OVER WESTERN
WA DURING THE NEXT 12 HOURS FOR A WET PERIOD OF WEATHER. SO FAR THE
MODELS APPEAR ON TRACK AND WE ARE STILL LOOKING AT 2-4 INCHES OF
PRECIP IN THE MOUNTAINS THROUGH SUN MORNING. HEAVY RAIN WILL FORCE
SHARP RISES ON THE RIVERS WHICH ARE ALREADY RUNNING HIGH FROM RECENT
HEAVY PRECIP. A FLOOD WATCH REMAINS IN EFFECT FOR PORTIONS OF
WESTERN WASHINGTON AS A FEW RIVERS MAY REACH FLOOD STAGE. SNOW
LEVELS WILL REMAIN HIGH - OVER 7000 FT IN THE CENTRAL CASCADES AND
OLYMPICS. EXPECT HEAVY RAIN IN THE LOWLANDS AS WELL WITH 1-3 INCHES
ALONG THE COAST AND UP TO 1 INCH IN THE INTERIOR. THERE IS A CLASSIC
RAIN SHADOW OVER THE EASTERN STRAIT WITH DOWNSLOPE FLOW OFF THE
OLYMPICS...WITH HARDLY ANY RAIN AT SEQUIM. IN ADDITION...IT WILL BE
WINDY AT THE CENTRAL COAST AND ADMIRALTY INLET AREA THROUGH EARLY
THIS EVENING - 25 TO 35 MPH WITH GUSTS TO 50 MPH.

THE BAROCLINIC BAND WILL PUSH OUT OF WESTERN WA SUNDAY MORNING WITH
RAIN TURNING OVER TO SCATTERED SHOWERS...AND HEAVY PRECIP ENDING. WE
MAY SEE A PSCZ DEVELOP OVER SNOHOMISH COUNTY SUNDAY AFTERNOON. THE
TRAILING UPPER LEVEL TROUGH WILL THEN BRING A FEW MORE SHOWERS TO
WESTERN WA SUN NIGHT INTO MONDAY.

HIGH PRES WILL START TO BUILD INLAND MON EVENING WITH DRIER WEATHER
EXPECTED. DRY WEATHER WILL CONTINUE INTO TUE WITH TEMPS CLOSE TO
NORMAL. 33

.LONG TERM...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL MAINTAIN DRY
AND STABLE WEATHER ACROSS WESTERN WA WED AND THU...POSSIBLY INTO
PART OF FRIDAY AS WELL. WE SHOULD SEE SOME SUN ON THESE DAYS WITH
TEMPS IN THE 50S TO LOWER 60S. MODELS THEN SHOW A WEAK UPPER LEVEL
DISTURBANCE ROLLING THROUGH SOUTHERN B.C. FRI AFTERNOON OR EVENING
WHICH MAY BRING A FEW SHOWERS BACK TO THE REGION. BOTH THE GFS AND
EURO TRY TO REBUILD THE RIDGE OVER NEXT WEEKEND FOR ANOTHER BREAK IN
THE WEATHER. 33

&&

.HYDROLOGY...A FLOOD WARNING CONTINUES FOR THE SKOKOMISH RIVER AT
POTLATCH IN MASON COUNTY FOR MINOR FLOODING. THE RIVER FELL BELOW
FLOOD STAGE FRIDAY NIGHT BUT WILL RISE BACK ABOVE FLOOD STAGE
TONIGHT DUE TO HEAVY RAIN IN THE OLYMPICS.

MODERATE TO HEAVY RAIN WILL CONTINUE TONIGHT WITH SNOW LEVEL OF 7000
TO 8000 FEET...LEADING TO RENEWED RISES ON ALL AREA RIVERS. FLOOD
PRONE RIVERS LIKE THE PUYALLUP AT ORTING WILL NEED TO BE WATCHED.
OTHER RIVERS THAT CAME CLOSE TO OR DID GO OVER FLOOD STAGE THIS LAST
ROUND LIKE THE COWLITZ AT RANDLE AND THE SNOQUALMIE AT CARNATION
ALSO BEAR WATCHING. WILL ALSO NEED TO WATCH THE TOLT. A FLOOD WATCH
REMAINS IN EFFECT. HEAVY PRECIP WILL END SUNDAY MORNING. 33

&&

.AVIATION...AN UPPER TROF OFFSHORE WILL CONTINUE MOVING E AND WILL
MOVE ACROSS THE AREA LATE TONIGHT OR EARLY SUNDAY. STRONG WLY FLOW
ALOFT. A CDFNT OFFSHORE WILL SWEEP ACROSS THE BY 0900 UTC. LOW LEVEL
SLY FLOW WILL WEAKEN AND BECOME WLY OVERNIGHT. CIGS WILL MAINLY BE
IN THE 1-2K FT RANGE THROUGH TONIGHT. EXPECT THE RAIN AND FOG TO
REDUCE VSBYS INTO THE 1-3SM AT TIMES UNTIL AT LEAST 0600 UTC.

KSEA...CIGS WILL MAINLY BE IN THE 1-2K FT RANGE THROUGH TONIGHT BUT
EXPECT OCCASIONAL CIGS IN THE 500-900 FT RANGE BETWEEN 0000 UTC AND
0600 UTC SUNDAY. VSBYS WILL ALSO BE IN THE 1-3SM RANGE AT TIMES DUE
TO RAIN AND FOG. EXPECT SOME IMPROVEMENT IN THE WAKE OF THE CDFNT.
FROPA IS EXPECTED BETWEEN 0600 AND 0800 UTC. WINDS WILL PICK UP OUT
OF THE S OR SW AT 10-15 KT THIS EVENING. THERE WILL LIKELY BE
OCCASIONAL GUSTS NEAR 25 KT TIL ABOUT 0800 UTC.

&&

.MARINE...
A STRONG COLD FRONT EXTENDING FROM A 988 MB LOW NEAR HAIDA GWAII
WILL MOVE ACROSS THE AREA BY MIDNIGHT TONIGHT. THE GALE FORCE WINDS
OCCURRING ACROSS PARTS OF THE AREA WILL END BY 10 PM PST TONIGHT.
MEANWHILE...LIGHT WESTERLY FLOW WILL PREVAIL IN THE WAKE OF THE
FRONT ON SUNDAY. EXPECT A WEAK SURFACE TROUGH TO MOVE ACROSS THE
AREA SUNDAY NIGHT. THIS WILL CAUSE THE ONSHORE FLOW TO STRENGTHEN
SOMEWHAT ON MON. HIGH PRES OVER THE AREA WILL RESULT IN MUCH WEAKER
FLOW ON TUE.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORY IN EFFECT UNTIL 7 PM PST THIS EVENING FOR THE
     ADMIRALTY INLET AREA AND CENTRAL COAST.

     FLOOD WATCHES AND/OR WARNINGS REMAIN IN EFFECT FOR PARTS OF
     THE CWA.

PZ...GALE WARNINGS ARE IN EFFECT FOR ALL WATERS EXCEPT THE
     CENTRAL/WESTERN STRAIT OF JUAN DE FUCA AND THE PUGET SOUND/
     HOOD CANAL.

     SMALL CRAFT ADVISORIES ARE EFFECT FOR THE REMAINING WATERS
     EXCEPT THE CENTRAL STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 5 PM PDT
     SUNDAY FOR THE GRAYS HARBOR BAR.

&&

$$

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