085
FXUS66 KSEW 110959
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
259 AM PDT WED JUN 11 2025
SYNOPSIS
A WEAK UPPER TROUGH WILL APPROACH WESTERN WASHINGTON
TODAY THEN SETTLE OVER THE AREA INTO EARLY NEXT WEEK. THIS WILL
LEAD TO COOLER TEMPERATURES, INCREASED CLOUD COVER, AND OCCASIONAL
CHANCES FOR MOUNTAIN SHOWERS AND COASTAL DRIZZLE.
SHORT TERM /TODAY THROUGH FRIDAY/
UPPER RIDGING OVER THE AREA
CONTINUES TO WEAKEN EARLY THIS MORNING AS AN UPPER TROUGH
OFFSHORE APPROACHES THE AREA. LOW LEVEL ONSHORE FLOW CONTINUES TO
RAMP UP WITH THE OTH/SEA GRADIENT NOW AROUND 5 MILLIBARS. AS A
RESULT, COASTAL STRATUS REACHED SHELTON A COUPLE HOURS AHEAD OF
YESTERDAY MORNING. AT THIS RATE, MUCH OF CENTRAL/SOUTHERN PUGET
SOUND SHOULD SEE SOME LOW CLOUDS THIS MORNING BEFORE THEY BURN
BACK TOWARD THE COAST. THE AIR MASS CONTINUES TO COOL AS THE
MARINE INFLUENCE TAKES HOLD. INTERIOR HIGH TEMPERATURES WILL BE IN
THE UPPER 60S TO MID 70S WHILE THE IMMEDIATE COAST STRADDLES THE
60 DEGREE MARK.
AN UPPER TROUGH AXIS IS STILL ON TRACK TO SHIFT ONSHORE LATER IN
THE DAY ON THURSDAY. IT STILL LOOKS TO BE LACKING ANYTHING OF
SUBSTANCE IN TERMS OF PRECIP, BUT IT WILL PROVIDE MOSTLY CLOUDY
SKIES, BELOW AVERAGE TEMPERATURES, AND PERHAPS A LITTLE MORNING
DRIZZLE NEAR THE COAST. FRIDAY LOOKS SIMILAR AS UPPER TROUGHING
REMAINS POSITIONED OVER THE REGION.
LONG TERM /SATURDAY THROUGH TUESDAY/
UPPER TROUGHING IS
EXPECTED TO DIG SOUTHWARD OFFSHORE OVER THE WEEKEND. THIS WILL
LEAD TO SOME MODEST HEIGHT INCREASES OVER WESTERN WASHINGTON. THE
LOW LEVEL FLOW WILL REMAIN ONSHORE, BUT WILL RELAX SOMEWHAT. THIS
SHOULD GIVE INTERIOR AREAS A SLIGHT WARMING TREND AND LESS
MORNING STRATUS WHILE COASTAL AREAS PROBABLY WON'T SEE MUCH OF
BENEFIT. THE FORECAST PICTURE STILL REMAINS SOMEWHAT MURKY AS WE
MOVE INTO EARLY NEXT WEEK. THE ENSEMBLES REMAIN SPLIT WITH THE
EURO SUITE FAVORING LOWERING HEIGHTS AND BETTER CHANCES OF PRECIP
WHILE A MAJORITY OF THE GFS ENSEMBLES MAINTAIN HIGHER HEIGHTS AND
DRIER/WARMER CONDITIONS. CURRENT FORECASTS FOR MONDAY AND TUESDAY
REFLECT THE NBM 50TH PERCENTILE FORECASTS WHICH BASICALLY TAKE THE
MIDDLE GROUND WITH LOW END SHOWER CHANCES AND TEMPERATURES A
SMIDGE ABOVE NORMAL.
AVIATION
SOUTHWESTERLY FLOW ALOFT WITH UPPER LEVEL TROUGH
OFFSHORE REACHING THE AREA THURSDAY. ONSHORE FLOW IN THE LOWER
LEVELS.
LOW END MVFR/IFR CEILINGS ALONG THE COAST AND OVER THE LOWER
CHEHALIS VALLEY. LEADING EDGE OF THE STRATUS NEAR KPWT AT 10Z.
STRATUS CONTINUING TO MOVE EAST THIS MORNING REACHING THE CENTRAL
PUGET SOUND 12-13Z. MOSTLY IFR CEILINGS WITH THE STRATUS IN THE
CENTRAL SOUND WITH THE LOWER TERMINALS CEILINGS NEAR 1000 FEET.
THE LAYER IS SHALLOW AND WILL DISSIPATE BACK TO THE COAST 17Z-19Z.
MOSTLY CLEAR SKIES THIS AFTERNOON. STRATUS FORMING AGAIN ALONG
THE COAST EARLY THIS EVENING WITH MVFR CEILINGS. STRATUS MOVING
INLAND A LITTLE FASTER TONIGHT WITH MVFR CEILINGS REACHING THE
CENTRAL PUGET SOUND 08Z-10Z.
KSEA...STRATUS REACHING THE TERMINAL 12-13Z WITH IFR CEILINGS AND
POSSIBLE SLIGHT VISIBILITY RESTRICTIONS. STRATUS DISSIPATING
AROUND 17Z. MVFR STRATUS RETURNING TO THE TERMINAL AROUND 09Z
EARLY THURSDAY MORNING. SOUTHWEST WIND 6 TO 10 KNOTS. FELTON
MARINE
SURFACE HIGH PRESSURE CENTERED OFFSHORE WITH LOWER
PRESSURE INLAND THROUGH FRIDAY. THE HIGH WILL BUILD OVER THE
WATERS DURING THE WEEKEND. A WEAKENING FRONT WILL REACH THE AREA
MONDAY.
DIURNAL WESTERLY PUSHES THROUGH STRAIT OF JUAN DE FUCA ARE
EXPECTED EACH EVENING, WITH THE STRONGEST OF THESE TONIGHT. SMALL
CRAFT ADVISORY IS IN EFFECT FOR TONIGHT WITH POSSIBLE SMALL CRAFT
ADVISORY WESTERLIES IN THE EVENING THURSDAY INTO THE WEEKEND.
SMALL CRAFT ADVISORY FOR THE OUTER COASTAL WATERS DUE TO SEAS
REMAINING GENERALLY 8 TO 10 FT WITH DOMINANT PERIODS REMAINING
8 TO 10 SECONDS THROUGH AT LEAST THURSDAY NIGHT. NORTHWESTERLY
WINDS 20 TO 25 KNOTS TODAY WILL EASE SLIGHTLY TONIGHT INTO
THURSDAY. FELTON
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM PDT THURSDAY
FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 6 AM PDT FRIDAY FOR COASTAL WATERS
FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL
WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-
COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10
TO 60 NM.
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