Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 272127
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
230 PM PDT WED MAY 27 2015

.SYNOPSIS...RELATIVELY WEAK LOW LEVEL ONSHORE FLOW WILL PREVAIL FOR
THE NEXT SEVERAL DAYS...WITH ABOVE NORMAL TEMPERATURES AND MOSTLY
SUNNY DAYS. AN UPPER LOW WILL BRING SHOWERS AND COOLER WEATHER THE
FIRST PART OF NEXT WEEK.

&&

.SHORT TERM...WEAK HIGH PRESSURE ALOFT WILL BUILD OVER WESTERN
WASHINGTON TONIGHT AND THURSDAY. AT THE SAME TIME...LOW LEVEL
ONSHORE FLOW WILL WEAKEN A BIT AND TURN MORE NORTHERLY. THE UPSHOT
IS AREAS OF MORNING LOW CLOUDS THEN MOSTLY SUNNY THURSDAY. HIGHS
WILL BE IN THE 70S TO LOWER 80S INLAND.

500 MB HEIGHTS WILL FALL SLIGHTLY FRIDAY AND SATURDAY AS AN UPPER
LOW OVER BRITISH COLUMBIA SAGS SOUTH AND THEN EAST. THIS WILL CAUSE
LOW LEVEL ONSHORE FLOW TO INCREASE A BIT. THAT SAID...IT DOES NOT
LOOK LIKE THESE CHANGES WILL HAVE MUCH AFFECT ON THE WEATHER. LOW
LEVEL MOISTURE WILL BE LIMITED FOR MOSTLY SUNNY DAYS AFTER SOME
MORNING LOW CLOUDS. 850 MB TEMPERATURES WILL REMAIN ABOUT THE SAME
FRIDAY AND HIGHS SHOULD ONCE AGAIN BE IN THE 70S TO LOWER 80S FOR
THE INTERIOR. THERE WILL PROBABLY BE A FEW DEGREES OF COOLING
SATURDAY BUT TEMPERATURES WILL STILL BE ABOVE NORMAL.

THERE WILL BE ENOUGH INSTABILITY OVER THE CASCADES FOR A CHANCE OF
AFTERNOON AND EVENING SHOWERS THURSDAY AND FRIDAY WITH THE BEST
CHANCES WILL BE NEAR THE CREST. SCHNEIDER

.LONG TERM...SUNDAY WILL BE ANOTHER MOSTLY SUNNY AFTER SOME MORNING
LOW CLOUDS. HIGHS MIGHT EVEN WARM A LITTLE AS AN UPPER LOW
APPROACHES FROM THE SOUTHWEST AND LOW LEVEL ONSHORE FLOW EASES.

THE AFOREMENTIONED UPPER LOW WILL MOVE OVER OREGON ON MONDAY.
MOISTURE COMING UP FROM THE SOUTH WITH THIS LOW WILL BRING AN
INCREASING CHANCE OF SHOWERS TO THE AREA. HIGHS WILL COOL INTO THE
60S. THE UPPER LOW WILL MOVE INLAND TO THE SOUTH...CLOSE ENOUGH TO
KEEP SHOWERS AND CLOUDS OVER THE AREA THROUGH TUESDAY WITH HIGHS
REMAINING IN THE 60S.

WEAK HIGH PRESSURE ALOFT WILL BUILD OVER THE REGION ON WEDNESDAY.
THIS SHOULD ALLOW THINGS TO DRY OUT AND THERE WILL PROBABLY BE SOME
SUNSHINE BY AFTERNOON. SCHNEIDER

&&

.AVIATION...NORTHERLY FLOW ALOFT. LIGHT ONSHORE FLOW. MARINE STRATUS
IS ALONG THE COAST THIS AFTERNOON BUT MOST OF IT HAS BURNED OFF IN
THE INTERIOR. AREAS OF LOW CLOUDS ARE LIKELY TO DEVELOP OVERNIGHT
AND BURN OFF BY MIDDAY THURSDAY.

KSEA...MOSTLY CLEAR SKIES TONIGHT AND A FEW HOURS OF MORNING LOW
CLOUDS THURSDAY.

&&

.MARINE...HIGH PRESSURE IS OFFSHORE WITH LOWER PRESSURE INLAND.
WESTERLY FLOW IN THE STRAIT OF JUAN DE FUCA COULD INCREASE TO SMALL
CRAFT ADVISORY STRENGTH BY EVENING.

&&

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

&&

$$

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