043
FXUS66 KSEW 140310
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
810 PM PDT TUE OCT 13 2026
UPDATE
LIGHT RAIN SHOWERS AND DRIZZLE EVIDENT OVER THE COAST, OLYMPIC PENINSULA
AND ISOLATED AREAS OF THE INTERIOR. THIS ACTIVITY WILL PERSIST
THROUGHOUT THE EVENING AND BECOME MORE WIDESPREAD OVERNIGHT
INTO THE EARLY MORNING ON WEDNESDAY AS A WEAK FRONTAL SYSTEM
PROGRESSES THROUGH THE AREA. OVERNIGHT LOWS ARE TO BOTTOM OUT
INTO THE MID 40S TO LOWER 50S. THE PREVIOUS DISCUSSION REMAINS
BELOW ALONG WITH AN UPDATED MARINE AND AVIATION SECTION.
SYNOPSIS
A WEAK FRONT WILL PASS THROUGH TODAY INTO WEDNESDAY FOR A FEW
SHOWERS ACROSS THE NORTH INTERIOR, OLYMPICS AND CASCADES. A
RIDGE WILL BUILD OVER THE REGION THROUGH THE END OF THE WEEK FOR
ANOTHER ROUND OF WARM AND DRY CONDITIONS. THE PATTERN FLIPS TO
UNSETTLED THIS WEEKEND AND EARLY NEXT WEEK AS A COUPLE OF
SYSTEMS PASS THROUGH.
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/
A SHORTWAVE TROUGH WILL PASS TO THE NORTH IN B.C. TONIGHT INTO
WEDNESDAY. THE ASSOCIATED LOW PRESSURE SYSTEM WITH THIS TROUGH
IS LOCATED OVER GRAHAM ISLAND THIS AFTERNOON, WITH A WARM FRONT
EXTENDING DOWN THE PACIFIC OCEAN JUST OFFSHORE OF THE COASTLINE.
CLOUD COVERAGE WILL REMAIN FAIRLY INTACT FOR MOST OF THE DAY AS
THE SYSTEM PASSES THROUGH. THERE REMAINS A CHANCE OF SHOWERS
GOING INTO WEDNESDAY MORNING, ALTHOUGH COVERAGE IS EXPECTED TO
REMAIN CONFINED TO THE NORTHERN PARTS OF THE COVERAGE AREA
(NORTH OLYMPICS/CASCADES, AND INTERIOR). RAIN AMOUNTS WILL BE
LIGHT, AND ONLY THE NEAH BAY TO QUILLAYUTE AREAS WILL SEE ANY
BUMP IN WIND SPEEDS WITH GUSTS UP TO 20 MPH THIS
EVENING/WEDNESDAY MORNING. THE ASSOCIATED COLD FRONT WILL TRACK
MORE TOWARDS THE CANADIAN SIDE OF THE BORDER.
HIGH PRESSURE WILL BUILD BACK IN UNDER A RIDGE, BEGINNING LATE
WEDNESDAY AND BUILDING INTO THURSDAY. CONDITIONS WILL DRY OUT
GOING INTO THURSDAY WITH SKIES GRADUALLY CLEARING OUT (EXCEPT
FOR THE MORNING PERIOD WHERE THERE WILL BE A CHANCE OF SOME
PATCHY FOG IN A FEW LOW-LYING AREAS SHOULD CLOUD COVERAGE CLEAR
OUT). BUT OTHERWISE, TEMPERATURES WILL GRADUALLY WARM ON
THURSDAY WITH HIGHS BACK INTO THE UPPER 60S TO MID 70S, AND
LOWS IN THE UPPER 40S TO LOW 50S. THE HIGH PRESSURE/RIDGE
PATTERN WILL RESULT IN A BRIEF PERIOD OF OFFSHORE FLOW, WITH
WINDS BECOMING GUSTY IN THE CASCADES THURSDAY MORNING UP TO 20
TO 30 MPH. WITH FUELS LARGELY RECOVERED FROM RECENT RAINS, FIRE
WEATHER CONDITIONS ARE NOT EXPECTED TO BE A CONCERN WITH THIS
PATTERN.
LONG TERM /FRIDAY THROUGH TUESDAY/
THE DRY PATTERN FROM THURSDAY WILL CONTINUE INTO FRIDAY, WITH
FRIDAY BEING THE WARMEST/DRIEST DAY OF THE FORECAST. MORE AREAS
WILL ALSO SEE HIGHS INTO THE MID 70S, AND A FEW CASCADE VALLEY
LOCATIONS MAY SEE AN ISOLATED INSTANCE OF AN 80. ONCE AGAIN,
BREEZY EAST WINDS WITH GUSTS UP TO 20-30 MPH WILL BE LIKELY
FRIDAY MORNING. THE PATTERN WILL SHIFT GOING INTO THE WEEKEND AS
THE RIDGE DEPARTS. A TROUGH WILL DIG SOUTHWARD FROM ALASKA WITH
A COUPLE OF SYSTEMS PASSING THROUGH THIS WEEKEND AND EARLY NEXT
WEEK. THE FIRST SYSTEM SATURDAY WILL BE QUICK, WITH THE BULK OF
THE PRECIP FALLING AS RAIN WITH SNOW LEVELS OVER 8,000 FT. A FEW
NORTH CASCADE LOCATIONS MAY SEE UP TO AN INCH OF OF RAIN (AS
WELL AS SOME SNOW AT THE HIGHEST ELEVATIONS). THE SYSTEM EARLY
NEXT WEEK (LATE SUNDAY THROUGH TUESDAY) WILL BE COOLER AND
WETTER OVERALL (BUT SPREAD OUT OVER A 48 HOUR PERIOD COMPARED TO
THE SATURDAY SYSTEM). SNOW LEVELS WILL DROP TO 5,000 FT WHICH
SHOULD LEAD TO MORE SNOW IN THE MOUNTAINS. WINDS WILL BECOME
BREEZY AT TIMES WITH BOTH SYSTEMS, BUT THE RISK FOR HAZARDOUS
WINDS AT ADVISORY LEVEL REMAIN LOW AT THIS TIME.
HPR
AVIATION
GENERALLY LOW END VFR TO MVFR ACROSS THE WESTERN WASHINGTON
TERMINALS THIS EVENING AS A FRONTAL SYSTEM PUSHES INLAND, BRINGING
LIGHT RAIN AND WIDESPREAD CLOUDS. MORE WIDESPREAD MVFR CONDITIONS
ARE EXPECTED TO EXPAND INLAND EARLY WEDNESDAY AFTER ROUGHLY 10Z,
WITH AREAS OF IFR/LIFR ALONG THE PACIFIC COAST, STRAIT OF JUAN DE
FUCA, AND KITSAP PENINSULA. SOUTHERLY WINDS INCREASE A BIT TOWARD 10
KT AFTER 06Z TONIGHT INTO EARLY WEDNESDAY. WINDS THROUGH THE TAF
PERIOD WILL REMAIN MOSTLY SW TO SE AT 10 KT OR LESS. CONDITIONS WILL
DRY OUT WEDNESDAY AFTERNOON, WITH MOST INLAND TERMINALS RETURNING TO
VFR AS LOW AND MID CLOUDS ERODE. AREAS CLOSER TO THE COAST WILL
LIKELY CONTINUE TO SEE MVFR TO IFR CEILINGS THROUGH WEDNESDAY
EVENING.
KSEA...VFR THIS EVENING UNDER A SOLID MID-LEVEL CLOUD DECK THAT WILL
CONTINUE TO THICKEN AND LOWER THROUGH THE EVENING. MVFR CEILINGS ARE
FAVORED TO DEVELOP EARLY WEDNESDAY MORNING, WITH A 10%-15% CHANCE OF
IFR CEILINGS. LIGHT SOUTHWEST AND INCREASE TO AROUND 7-9 KT THIS
EVENING, EASING WEDNESDAY MORNING AND REMAINING OUT OF THE SOUTH
THROUGH MUCH OF THE DAY WEDNESDAY BEFORE SHIFTING NORTHEASTERLY
WEDNESDAY EVENING.
15
MARINE
A FRONTAL SYSTEM WILL CONTINUE TO MOVE INLAND TONIGHT INTO
WEDNESDAY. WINDS ALONG THE NORTHERN COASTAL WATER COASTLINE MAY
APPROACH SMALL CRAFT, BUT ARE EXPECTED TO REMAIN BELOW 20 KT. HIGH
PRESSURE WILL REBUILD INLAND WEDNESDAY THROUGH FRIDAY AS A THERMAL
TROUGH BUILDS ALONG THE COAST, GENERATING OFFSHORE FLOW. THE FLOW
WILL SWITCH BACK TO ONSHORE LATER THIS WEEKEND INTO NEXT WEEK AS A
COUPLE OF FRONTAL SYSTEMS PASS THROUGH. WINDS WILL LIKELY SURPASS 20
KT OVER MOST AREA WATERS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
SEAS WILL REMAIN AROUND 4 TO 7 FT THROUGH THE WEEKEND, THEN INCREASE
TO 10 TO 14 FT WITH THE SYSTEM EARLY NEXT WEEK, PEAKING MONDAY.
HPR/15
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
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