Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 151604
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 AM PDT WED OCT 15 2014

.SYNOPSIS...AN UPPER LEVEL TROUGH WILL MOVE THROUGH WESTERN
WASHINGTON TODAY GIVING SHOWERS AND A CHANCE OF THUNDERSTORMS.
SHOWERS WILL TAPER OFF TONIGHT. A FRONT WILL REACH THE AREA FRIDAY.
HIGH PRESSURE WILL BUILD OVER THE AREA SATURDAY. A WET FRONTAL
SYSTEM WILL ARRIVE EARLY NEXT WEEK.

&&

.SHORT TERM...A TROUGH MOVES THROUGH WESTERN WA TODAY FOR SHOWERS
AND A CHANCE OF TSTMS. COOL AIR ALOFT HAS PUT THE SNOW LEVEL AROUND
6500 FEET AND IT WILL DROP ANOTHER 1000 FEET THROUGH THIS EVENING.
THE WEBCAM AT THE TOP OF CRYSTAL SHOWED AN INCH OF SNOW AT 7AM...BUT
PARADISE IS BARE SO FAR. AN SPS MENTIONS SNOW FOR THE HIGHER PEAKS.
SHOWERS WILL DIMINISH TONIGHT AND THURSDAY SHOULD BE DRY...AND IT
MAY TURN OUT TO BE A RATHER NICE DAY AS LOW LEVEL OFFSHORE FLOW
DEVELOPS. A FRONT WILL BECOME N-S ORIENTED AND STRETCH AND SLOW DOWN
AS IT NEARS THE COAST THURSDAY NIGHT...PUSHING INLAND OVER WRN WA
SLOWLY ON FRIDAY.

.LONG TERM...THE OFFSHORE FRONT MOVES INLAND FRIDAY NIGHT AND POST
FRONTAL SHOWERS DECREASE EARLY SATURDAY. IN RESPONSE TO STRONG
DEVELOPMENT OVER THE WEST CENTRAL GULF OF ALASKA ON SATURDAY...ALL
LONG RANGE MODELS NOW DEVELOP A RATHER STRONG RIDGE AT THE SURFACE
AND ALOFT FROM THE CANADIAN ROCKIES SOUTHWARD INTO EASTERN OREGON.
OFFSHORE FLOW WILL LIKELY GIVE DRY CONDITIONS TO THE INTERIOR OF
WESTERN WASHINGTON ON SUNDAY...AND NICE OFFSHORE FLOW WILL ALLOW
TEMPERATURES TO RISE TO AROUND 70 DEGREES IN THE PUGET SOUND
LOWLANDS. THE OFFSHORE FRONT WILL BECOME INCREASINGLY N-S ORIENTED
SUNDAY THEN SLOWLY PUSH INLAND AND WEAKEN SUNDAY NIGHT INTO EARLY
NEXT WEEK. WINDY CONDITIONS WITH THE INCOMING FRONT SHOULD BE
LIMITED TO THE COASTAL AREAS AND PORTIONS OF THE NORTH INTERIOR.
ALBRECHT

&&

.AVIATION...AN UPPER LEVEL TROUGH WILL MOVE TROUGH WESTERN
WASHINGTON TODAY GIVING SHOWERS AND A CHANCE OF THUNDERSTORMS. FLOW
ALOFT IS SOUTHERLY AND WILL BECOME WESTERLY IN THE AFTERNOON. AT THE
SURFACE FLOW IS MODERATE SOUTHERLY AND ONSHORE. THE AIR MASS IS
MOIST AND UNSTABLE.

CEILINGS ARE MAINLY VFR WITH SOME MVFR IN SHOWERS. SHOWER ACTIVITY
WILL TAPER THIS EVENING AS FLOW BECOMES WESTERLY.

KSEA...SHOWERS TODAY WITH MAINLY VFR CEILINGS 3-5K FT. THE CHANCE OF
THUNDERSTORMS DOES NOT SEEM HIGH ENOUGH TO INCLUDE IN THE TAF.
SOUTHERLY SURFACE WINDS THIS AFTERNOON AND EVENING 20015G25KT. CHB

&&

.MARINE...SOUTHERLY SURFACE GRADIENTS HAVE BEEN INCREASING AND IT
NOW APPEARS LIKELY THAT SMALL CRAFT ADVISORY WINDS WILL AFFECT MOST
WATERS TODAY. HAVE ISSUED THE ADVISORIES FOR TODAY AND AGAIN LATER
TONIGHT WHEN A SECOND SURGE OF WIND IS FORECAST BY THE MODELS.

A STRONGER PACIFIC FRONTAL SYSTEM WILL AFFECT THE REGION THURSDAY
THROUGH FRIDAY. MODELS SHOW GALES OVER THE COASTAL WATERS DURING
THIS PERIOD WITH COMBINED SEAS OF 14 TO 20 FEET. GALES MAY ALSO
OCCUR AT THE ENTRANCES TO THE STRAIT OF JUAN DE FUCA. FOR NOW HAVE
POSTED A GALE WATCH FOR THE COAST FOR THURSDAY MORNING THROUGH
FRIDAY AFTERNOON. THIS SYSTEM WILL EXIT FRIDAY NIGHT WITH HIGH PRES
MOVING INLAND ON SATURDAY. ANOTHER STRONG FRONT WILL APPROACH
WASHINGTON SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.

PZ...SMALL CRAFT ADVISORY COAST...EAST ENTRANCE...ADMIRALTY INLET...
     PUGET SOUND AND HOOD CANAL.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH COAST.

&&

$$

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