Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 232141
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
240 PM PDT SAT APR 23 2016

.SYNOPSIS...SHOWERS WILL INCREASE THIS EVENING. AN UPPER LEVEL
TROUGH WILL MOVE OVER WESTERN WASHINGTON ON SUNDAY WITH SHOWERS
AND COOL WEATHER. WEAK HIGH PRESSURE WILL BUILD MONDAY NIGHT
AND TUESDAY.

&&

.SHORT TERM...SHOWERS WILL INCREASE TONIGHT AND SUNDAY AS A COLD
UPPER TROUGH MOVES OVER WRN WA. THE AIR WILL BECOME UNSTABLE WITH
A CHANCE OF TSTMS...MAINLY SUNDAY AFTERNOON AS 500MB COOLS TO ARND
-30C. SUNDAY WILL BE THE CHILLIEST DAY...THEN HIGHS WILL CREEP UP
A COUPLE DEGREES ON MONDAY AND AGAIN TUESDAY WITH MORE SUNSHINE.

.LONG TERM...AFTER THE WEAK UPPER RIDGE AND SOME SUNSHINE ON TUESDAY
A FRONT WILL APPROACH THE AREA TUE NIGHT. THE FRONT WILL PROBABLY
SPLIT AND THEN THAT UPPER TROUGH WILL DROP INTO OREGON AND CALIF
WED AND THU AS ANOTHER WEAK RIDGE BUILDS INTO WRN WA. MORE CLOUDS
AND A CHANCE OF SHOWERS ARE IN THE FORECAST AT TIMES...BUT OVERALL
PATTERN WILL BE PRETTY QUIET AND BENIGN.

&&

.AVIATION...A COLD FRONT WILL MOVE INLAND THIS EVENING FOR SHOWERS
ACROSS ALL OF WESTERN WA. THE FLOW ALOFT IS SOUTHWESTERLY. LOW LEVEL
ONSHORE FLOW WILL INCREASE WITH MVFR CIGS POSSIBLE. AN UPPER LEVEL
TROUGH WILL MAINTAIN A COOL AND UNSTABLE AIR MASS ON SUNDAY FOR
ADDITIONAL SHOWERS AND A CHANCE OF THUNDERSTORMS. A PUGET SOUND
CONVERGENCE ZONE WILL LIKELY FORM OVER KPAE. 33

KSEA...VFR CIGS THROUGH THIS AFTERNOON. SW WINDS AT THE SURFACE 10-
15 KT. SHOWERS DEVELOPING THIS EVENING WITH MVFR CIGS POSSIBLE.
PUGET SOUND CONVERGENCE ZONE FORMING NORTH OF THE TERMINAL ON
SUNDAY. 33

&&

.MARINE...ONSHORE FLOW WILL INCREASE TONIGHT AS A COLD FRONT MOVES
INLAND. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS.
WESTERLY GALES ARE POSSIBLE IN THE CENTRAL AND EAST STRAIT OF JUAN
DE FUCA. ONSHORE FLOW WILL CONTINUE THROUGH EARLY NEXT WEEK WITH
HIGH PRESSURE OVER THE NE PAC. A WEAK COLD FRONT WILL DISSIPATE OVER
THE COASTAL WATERS EARLY WEDNESDAY. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
     GALE WARNING CENTRAL AND EAST STRAIT OF JUAN DE FUCA.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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