Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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446
FXUS66 KSEW 300404
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT FRI APR 29 2016

.SYNOPSIS...A STRONG UPPER RIDGE WILL BRING DRY WARMER WEATHER
SATURDAY THROUGH MONDAY. A CHANCE OF SHOWERS WILL RETURN TUESDAY
THROUGH THURSDAY OF NEXT WEEK...WITH MOIST SOUTHERLY FLOW ALOFT
AND LOW LEVEL ONSHORE FLOW.

&&

.SHORT TERM...SHOWERS ARE WINDING DOWN TONIGHT AS AN UPPER LEVEL
TROUGH MOVES EAST OF THE CASCADES. KATX SHOWS ONLY ISOLATED SHOWERS
IN THURSTON...PIERCE AND IN THE CENTRAL CASCADES. THESE SHOWERS
SHOULD BE OVER BY MIDNIGHT.

AN UPPER LEVEL RIDGE WILL NUDGE INLAND ON SATURDAY FOR DRY AND MILD
WEATHER ACROSS WESTERN WA. NORTHERLY FLOW WILL SCOUR OUT THE MORNING
LOW CLOUDS FOR MOSTLY SUNNY SKIES. HIGH TEMPS WILL BE IN THE LOW TO
MID 60S...A FEW DEGREES ABOVE NORMAL.

THE UPPER LEVEL RIDGE WILL REMAIN OVER THE PAC NW ON SUNDAY FOR
ANOTHER DRY DAY. OFFSHORE FLOW WILL INCREASE WITH A THERMAL TROUGH
FORMING ALONG THE COAST. HIGHS WILL BE IN THE 70S TO LOWER 80S ALONG
THE COAST AND INTERIOR. IT WILL BE SLIGHTLY COOLER IN THE STRAIT OF
JUAN DE FUCA AND SAN JUANS WITH TEMPS MAINLY IN THE 60S.

MONDAY WILL BE THE WARMEST DAY OF THIS STRETCH WITH THE RIDGE STILL
OVERHEAD AND THE FLOW STILL OFFSHORE. EXPECT HIGHS IN THE LOW TO MID
80S IN THE INTERIOR. 33

.LONG TERM...PREVIOUS DISCUSSION...AN UPPER TROUGH WILL APPROACH FROM
THE WEST ON TUESDAY WITH INCREASINGLY MOIST SOUTHERLY FLOW ALOFT FOR
A CHANCE OF SHOWERS. INCREASING LOW LEVEL ONSHORE FLOW WILL COOL
HIGHS ON THE ORDER OF 10 DEGREES FROM MONDAY.

THIS GENERAL PATTERN WILL CONTINUE ON WEDNESDAY...MOIST SOUTHERLY
FLOW ALOFT FOR A CHANCE OF SHOWERS. THE UPPER TROUGH OFFSHORE WILL
TURN INTO A CUTOFF UPPER LOW WELL TO THE SOUTH ON THURSDAY AND
FRIDAY. THIS WILL KEEP MOST OF THE SHOWER THREAT TO THE SOUTH BUT
SOME ACTIVITY COULD CERTAINLY SNEAK UP FROM THE SOUTH OR EAST. THE
BEST CHANCES WILL BE OVER THE CASCADES. SCHNEIDER

&&

.AVIATION...UPPER LEVEL TROUGH OVER EASTERN WASHINGTON
SLOWLY MOVING EAST WITH UPPER LEVEL RIDGE BUILDING OFFSHORE. LIGHT
FLOW ALOFT BECOMING NORTHWESTERLY. LOW LEVEL ONSHORE FLOW CONTINUING
INTO SATURDAY.

CURRENT SKY CONDITIONS A BIT MORE OPTIMISTIC THAN MODELS
SUGGEST...WITH MAINLY SCATTERED CLOUDS OVER MOST LOCATIONS AT
HEIGHTS RANGING FROM 3500 FT TO 6000 FT. KOLM SEEMS TO BE AN
EXCEPTION AT THIS TIME...REPORTING BKN TO OVC CONDITIONS...BUT CIGS
STILL FALLING WITHIN THE ABOVE RANGE...THUS VFR CONDITIONS. WITH
LIGHT ONSHORE FLOW CONTINUING...EXPECT CIGS TO LOWER TO NEAR 2000
FEET 10Z-18Z SATURDAY...BUT WILL SCATTER OUT BY MIDDAY SATURDAY.

KSEA...SCATTERED CLOUDS AT 3.5K FT AND 6K FT THIS EVENING. CLOUDS
EXPECTED TO INCREASE OVERNIGHT WITH CIGS FALLING TO NEAR 2000 FEET
AROUND 12Z SATURDAY. GENERALLY LIGHT AND VARIABLE WINDS THIS EVENING
SHIFTING SOUTH TO SOUTHEAST AFTER 06Z. WINDS WILL RETURN TO
NORTHERLY BY SATURDAY AFTERNOON WITH SPEEDS 5-10 KTS. FELTON/SMR

&&

.MARINE...LOW LEVEL ONSHORE FLOW PATTERN CONTINUING INTO SATURDAY
WITH SMALL CRAFT ADVISORIES OVER THE COASTAL WATERS AND BORDERLINE
GALES IN THE STRAIT OF JUAN DE FUCA. WINDS IN THE STRAIT SEEM TO BE
DIMINISHING BELOW GALE CRITERIA...SO WILL ALLOW GALES TO EXPIRE AT
11 PM PDT TONIGHT. ONSHORE FLOW TURNS NORTHWESTERLY ON SATURDAY WITH
HIGH PRESSURE BUILDING INTO SOUTHERN BRITISH COLUMBIA. LOW LEVEL
FLOW TURNING OFFSHORE ON SUNDAY WITH THERMALLY INDUCED TROUGH ALONG
THE COAST. A RETURN TO LOW LEVEL ONSHORE FLOW WILL OCCUR LATER
MONDAY INTO TUESDAY.
FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...

WA...NONE.
PZ...SMALL CRAFT ADVISORIES COAST AND WEST ENTRANCE STRAIT OF JUAN
     DE FUCA.

     GALE WARNING CENTRAL AND EAST ENTRANCE STRAIT OF JUAN DE FUCA.

&&

$$

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