Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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FXUS66 KSEW 051015
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PDT SAT SEP 5 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL BRING DRY AND WARMER WEATHER
TO WESTERN WASHINGTON TODAY. A WEAK FRONT WILL BRING SOME RAIN TO
THE AREA ON SUNDAY. DRY WEATHER WILL RETURN FOR LABOR DAY. A WEAK
FRONT WILL BRUSH THE NORTH PART OF WESTERN WASHINGTON ON TUESDAY FOR
A CHANCE OF RAIN. STRONGER HIGH PRESSURE WILL BUILD STARTING AROUND
THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...SHOWERS WILL REMAIN EAST OF THE CREST TODAY AS AN
UPPER LEVEL LOW SPINS OVER EASTERN WASHINGTON AND OREGON. SKIES ARE
MAINLY CLEAR ACROSS WESTERN WA EARLY THIS MORNING BUT SATELLITE DOES
SHOW A STRATUS DECK ALONG THE WEST SLOPES OF THE CASCADES. THIS
STRATUS DECK MAY EXPAND WEST INTO PUGET SOUND THIS MORNING FOR A
CLOUDY START TO THE DAY. LATEST GUIDANCE SUGGESTS THIS STRATUS LAYER
WILL ONLY LINGER THROUGH THE MORNING HOURS...WITH SKIES BECOMING
MOSTLY SUNNY THIS AFTERNOON. TEMPERATURES WILL BE A FEW DEGREES
WARMER TODAY /MID 60S TO LOWER 70S/ ALTHOUGH STILL A FEW DEGREES
BELOW NORMAL.

A WEAK COLD FRONT WILL BRING SOME RAIN TO WESTERN WA LATE TONIGHT
AND SUNDAY AS IT CROSSES THROUGH WESTERN WA. SO EXPECT MORE CLOUDS
AND COOLER WEATHER WITH HIGHS MAINLY IN THE 60S. ISOLATED TO
SCATTERED SHOWERS WILL CONTINUE SUNDAY EVENING AS LOW LEVEL ONSHORE
FLOW INCREASES AND AN UPPER LEVEL TROUGH PASSES OVERHEAD.

AN UPPER LEVEL RIDGE WILL MOVE INLAND ON LABOR DAY FOR DRY WEATHER.
WILL LIKELY SEE SOME LINGERING LOW LEVEL MOISTURE AND CLOUDS IN THE
MORNING...THEN SKIES BECOMING MOSTLY SUNNY.

A WARM FRONT WILL MOVE INTO SOUTHERN B.C. ON TUESDAY WHICH MAY CLIP
WESTERN WA. BEST CHANCES OF SHOWERS WILL BE THE COAST...MOUNTAINS
AND NORTH PART NEAR THE CANADIAN BORDER. THE COLD FRONT MAY BRING A
FEW MORE SHOWERS TO THE AREA TUESDAY AFTERNOON. MODELS ARE A LITTLE
WETTER WITH THE COLD FRONT AND MAY NEED TO EXPAND POPS ACROSS THE
CWA. 33

.LONG TERM...A BROAD UPPER LEVEL RIDGE WILL REMAIN DOMINANT THROUGH
MUCH OF THE LONG TERM PERIOD...LEADING TO DRY AND WARMER WEATHER
ACROSS WESTERN WA. MODELS ARE IN PRETTY GOOD AGREEMENT THUS FAR.
TEMPERATURES WERE NUDGED UPWARDS A FEW DEGREES THROUGH THE PERIOD
WITH LOWER 80S POSSIBLE IN THE INTERIOR NEXT THU-SAT. 33

&&

.AVIATION...AN UPPER LEVEL LOW OVER OREGON IS SLOWLY MOVING S TODAY.
THE FLOW ALOFT IS NORTHERLY THIS MORNING THEN SWITCHING TO NWLY THIS
EVENING. VFR CONDITIONS SHOULD CONTINUE FOR MOST LOCATIONS WEST OF
PUGET SOUND EXCEPT ALONG THE COAST. OVER THE EASTERN PARTS OF PUGET
SOUND THERE ARE AREAS FOG AND LOW CLOUDS WHICH WILL PROBABLY SPREAD
INTO THE CENTRAL AREAS OF THE SOUND. THESE AREAS OF FOG OR LOW
CLOUDS HAVE MOSTLY IFR CONDITIONS. THE FOG AND LOW CLOUDS SHOULD
LIFT OR BURN OFF BY NOON.

KSEA...SLY WINDS 5 TO 10 KT FOR MOST OF THE DAY. VFR EARLY BUT BY
SUNRISE THE LOW CLOUDS OR FOG OVER THE EASTERN SOUND WILL PROBABLY
SPREAD WEST OR FORM OVER KSEA. IFR MORNING FOG OR LOW CLOUDS ARE
LIKELY AND SHOULD LIFT OR BURN OFF BY NOON. 13

&&

.MARINE...GRADIENTS WILL SWITCH TO MORE SWLY AND THEN SLY SATURDAY
INTO SUNDAY AS A SURFACE LOW PRESSURE SYSTEM AND ITS ASSOCIATED
FRONT DIP ALONG THE BC COAST AND INTO THE AREA. SMALL CRAFT ADVISORY
LEVEL WINDS WILL OCCUR IN THE STRAIT AHEAD OF THE FRONT EARLY
SATURDAY EVENING. WEAK TO MODERATE ONSHORE FLOW WILL RESUME LATE
SUNDAY AFTER THE LOW PASSES THROUGH AND CONTINUE THROUGH THE
BEGINNING OF NEXT WEEK. 13

&&

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

&&

$$

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