333
FXUS66 KSEW 110957
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
257 AM PDT THU SEP 11 2025
SYNOPSIS
BROAD UPPER LEVEL TROUGHING WILL SLOWLY SLIDE EAST
THURSDAY AND FRIDAY, BRINGING MOSTLY DRY CONDITIONS TO THE
REGION THAT WILL PERSIST INTO SATURDAY. BY SUNDAY, THE NEXT
WEATHER SYSTEM WILL BRING A CHANCE FOR PRECIPITATION BACK TO THE
REGION.
SHORT TERM /TODAY THROUGH SATURDAY/
AN UPPER LEVEL LOW
CONTINUES TO SPIN OVER THE PAC NW TODAY WITH SHOWERS MAINLY TO OUR
EAST (OVER EASTERN WA/OR). LOW CLOUDS WILL COVER MUCH OF THE
LOWLANDS THIS MORNING WITH SUNBREAKS EXPECTED THIS AFTERNOON.
EXPECT HIGH TEMPERATURES IN THE 70S WITH 60S ALONG THE COAST.
THE UPPER LOW WEAKENS AS IT SHIFTS SLIGHTLY EASTWARD ON FRIDAY,
WHILE WEAK HIGH PRESSURE BUILDS OVER WESTERN WA. OVERALL, A DRY
DAY ON TAP BUT ALSO A LITTLE COOLER WITH INCREASING ONSHORE FLOW.
THE NEXT INCOMING PACIFIC FRONTAL SYSTEM WILL STALL OFFSHORE ON
SATURDAY WITH THE RIDGE OVER WA STILL INTACT. THE AIR MASS WILL BE
WARMER WITH INTERIOR TEMPERATURES REACHING THE MID TO UPPER 70S.
HIGHS ALONG THE COAST WILL TRACK IN THE 60S TO LOWER 70S. 33
LONG TERM /SUNDAY THROUGH WEDNESDAY/
RAIN WILL INCREASE ON
SUNDAY AS AN UPPER LEVEL TROUGH SHIFTS INLAND. MOST AREAS WILL SEE
MEASURABLE RAIN WITH WETTING RAINS IN THE MOUNTAINS. THE COOLER
AIR MASS WILL KEEP TEMPERATURES DOWN AND IN THE 60S. SHOWERS WILL
LINGER INTO MONDAY BUT WILL TAPER DOWN AS THIS SYSTEM EXITS EAST.
DRIER WEATHER IS FAVORED MOVING TOWARD MIDWEEK AS HIGH PRESSURE
RETURNS. TEMPERATURE TRENDS LOOK CLOSE TO NORMAL. 33
AVIATION
UPPER LEVEL LOW CENTERED OVER NORTHERN CALIFORNIA WILL
SLOWLY MOVE EAST TODAY AND TONIGHT. TEMPORARY UPPER LEVEL RIDGE
BUILDING INTO WESTERN WASHINGTON LATER TONIGHT INTO FRIDAY.
NORTHEASTERLY FLOW ALOFT BECOMING WESTERLY TONIGHT. LIGHT ONSHORE
FLOW IN THE LOWER LEVELS.
IFR/LIFR STRATUS ALREADY COVERING MOST OF THE LOWLANDS SOUTH OF
SKAGIT COUNTY WITH THE EXCEPTION OF THE CENTRAL PUGET SOUND AREA.
STRATUS FILLING IN WITH IFR/LIFR CEILINGS OVER ALL THE LOWLANDS
BY 14Z. HIGHER TERMINALS ( KPAE AND KPWT ) VISIBILITIES BELOW A
MILE UNTIL 16Z. STRATUS DISSIPATING BACK TO THE COAST 19Z-21Z WITH
CLEAR SKIES OVER THE INTERIOR AFTER 21Z. MVFR CEILINGS REMAINING
ALONG THE COAST. STRATUS MOVING INLAND AGAIN EARLY FRIDAY MORNING.
KSEA...LIFR STRATUS JUST 5 MILES TO THE WEST OF THE TERMINAL AT
10Z/3 AM. VISIBILITIES LOWERING TO A MILE OR LESS 14Z-17Z
IMPROVING TO 3-5SM 17Z-18Z. STRATUS LIFTING TO IFR AROUND 18Z AND
MVFR 19Z BEFORE SCATTERING OUT AROUND 20Z. CLEAR SKIES INTO
TONIGHT WITH IFR STRATUS RETURNING TO THE TERMINAL AROUND 12Z
FRIDAY MORNING. LIGHT AND VARIABLE WIND BECOMING SOUTHWESTERLY 4
TO 6 KNOTS AROUND 15Z. WINDS TRYING TO COME AROUND TO NORTHWEST
22Z-02Z BUT LIKELY ENDING UP IN THE 250-280 DEGREE RANGE BEFORE
GOING BACK TO SOUTHWESTERLY AFTER 06Z. FELTON
MARINE
WEAK HIGH PRESSURE OVER THE WATERS WITH LOWER PRESSURE
EAST OF THE CASCADES WILL KEEP ONSHORE FLOW PATTERN GOING THROUGH
FRIDAY NIGHT. FRONT MOVING INTO THE COASTAL WATERS SATURDAY AND
INLAND SUNDAY. HIGH PRESSURE REDEVELOPS AGAIN FOR THE FIRST PART
OF NEXT WEEK.
SMALL CRAFT ADVISORY WESTERLY WINDS IN THE CENTRAL AND EASTERN
STRAIT OF JUAN DE FUCA TONIGHT AND AGAIN SUNDAY NIGHT. SMALL CRAFT
ADVISORY WINDS POSSIBLE OVER THE COASTAL WATERS SUNDAY.
SEAS GENERALLY IN THE 4 TO 6 FOOT RANGE WITH SLIGHTLY HIGHER SEAS
POSSIBLE SUNDAY INTO SUNDAY NIGHT. FELTON
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 2 AM PDT FRIDAY
FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
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