011
FXUS66 KSEW 230315
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
815 PM PDT WED OCT 22 2025
SYNOPSIS
A WEAK SYSTEM BRUSHING THE AREA THIS AFTERNOON WILL
EXIT THE AREA THIS EVENING. A MUCH STRONGER SYSTEM APPROACHING
THE AREA WILL BRING RAIN AND WINDY CONDITIONS THURSDAY AFTERNOON
INTO FRIDAY. A SECOND, DEVELOPING, BUT STRONG SYSTEM IS
EXPECTED SATURDAY FOR ANOTHER ROUND OF RAIN AND WIND. COOLER
CONDITIONS WILL FOLLOW SUNDAY WITH SNOW LEVELS BELOW ALL OF THE
PASSES BY SUNDAY. ACTIVE WEATHER WILL CONTINUE INTO NEXT WEEK.
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/
TODAYS WEAK SYSTEM
WILL FULLY EXIT THE AREA THIS EVENING LEAVING MID AND HIGH
LEVEL CLOUDS AND A FEW LINGERING SHOWERS OVER THE CASCADES. THE
FRONTAL SYSTEM APPROACHING THE COAST THURSDAY WITH THE BULK OF
THE WARM FRONTAL PRECIPITATION MOVING INTO BRITISH COLUMBIA
DURING THE AFTERNOON. NONETHELESS EXPECT A CHANCE OF LIGHT RAIN
ESPECIALLY ALONG THE COAST AND SKAGIT COUNTY NORTHWARD DURING
THE AFTERNOON. WINDS WILL BEGIN TO PICK UP ALONG THE COAST LATE
IN THE AFTERNOON AHEAD OF THE COLD FRONT, FOLLOWED BY WHIDBEY
ISLAND NORTH INTO SKAGIT AND WHATCOM COUNTIES IN THE EVENING
WITH GUSTS IN THE NEIGHBORHOOD 40 TO 45 MPH.
RAIN WITH THE FRONTAL BOUNDARY CONTINUES TO LOOK SLOW - PERHAPS
NOW WAITING TO PUSH INTO THE INTERIOR UNTIL WELL AFTER MIDNIGHT
INTO FRIDAY MORNING. THERE MAY BE ENOUGH INSTABILITY THAT A
SLIGHT CHANCE OF ISOLATED THUNDER IS ALSO POSSIBLE FRIDAY
MORNING ALONG THE COAST. FRIDAY WILL REMAIN A GENERALLY WET AND
BLUSTERY DAY. BALLPARK PRECIPITATION AMOUNTS REMAIN A HALF TO
AN INCH OF RAIN OVER THE INTERIOR WITH AROUND TWO INCHES ALONG
THE COAST. HEAVIEST RAINFALL WILL BE IN THE OLYMPICS WITH 2 TO 4
INCHES POSSIBLE. SNOW LEVELS GENERALLY IN THE 6000-7000 FOOT
RANGE MAKING THE PRECIPITATION RAIN IN ALL THE PASSES.
IN ADDITION TO THE WINDY CONDITIONS, THIS SYSTEM WILL BRING
LARGE, STEEP SEAS TO THE WASHINGTON COAST WITH A HIGH SURF
ADVISORY IN EFFECT THURSDAY NIGHT INTO FRIDAY MORNING FOR LARGE,
BREAKING WAVES 20 TO 22 FEET.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
GRAND ENSEMBLES
CONTINUE TO HIGHLIGHT ANOTHER, DEVELOPING FRONTAL SYSTEM WITH
STRONG SURFACE LOW MOVING INTO THE NE PACIFIC EARLY IN THE
WEEKEND. ENSEMBLE CLUSTERS INDICATING 20% OF THE GEFS AND ENS
MEMBERS FORECASTING A STRONGER SOLUTION FOR WASHINGTON AND
OREGON WITH THIS SYSTEM AND IT REMAINS WORTH MONITORING FOR THE
POTENTIAL FOR HIGH WINDS ALONG THE COAST SATURDAY INTO SATURDAY
NIGHT AND OVER THE INTERIOR SATURDAY NIGHT INTO SUNDAY MORNING.
ANOTHER ROUND OF RAIN WILL ACCOMPANY THIS FEATURE, WITH SNOW
LEVELS DROPPING BELOW THE HIGHER PASSES SATURDAY NIGHT AND SNOW
LEVELS BELOW ALL OF THE PASSES BY SUNDAY MORNING. A COOL UPPER
LEVEL TROUGH SUNDAY WILL KEEP SHOWERS OVER THE HIGH TERRAIN WITH
A FEW INCHES OF SNOW ACCUMULATIONS ABOVE 3000 FEET. ACTIVE
WEATHER LINGERING INTO EARLY WEEK REMAINS A SAFE BET.
AVIATION
MAINLY MVFR ALONG THE COAST AS LOW STRATUS SLOWLY
EXPANDS INLAND, AND MOSTLY VFR FURTHER INLAND WITH MID LEVEL CLOUDS
INCREASING TONIGHT. CLOUDS WILL CONTINUE TO STREAM INLAND OVERNIGHT,
WHICH WILL LIKELY MITIGATE THE INLAND SPREAD OF LOW STRATUS AND FOG,
BUT PATCHY FOG AND STRATUS MAY STILL FORM OVERNIGHT FOR MORE PRONE
TERMINALS CAUSING LOCALIZED IFR/LIFR. CONDITIONS WILL REMAIN MOSTLY
DRY THROUGH THURSDAY AFTERNOON BEFORE A FRONTAL SYSTEM MOVES INLAND,
BRINGING WIDESPREAD RAIN, BREEZY WINDS, AND LOWER CEILINGS LATE
THURSDAY. CONDITIONS WILL DETERIORATE TO WIDESPREAD MVFR/IFR WITH
GUSTS TO 30-40 KT ALONG THE COAST AND 20-30 KT ELSEWHERE OVERNIGHT
INTO FRIDAY MORNING.
KSEA...VFR THIS EVENING WITH INCREASING MID LEVEL CLOUDS AND
WEAKENING SOUTHERLY WINDS. ENSEMBLES MAINTAIN A CHANCE (15% TO 20%)
OF MVFR CEILINGS BRIEFLY DEVELOPING OVER THE TERMINAL EARLY THURSDAY
MORNING, BUT THE PRESENCE OF CLOUD COVER WILL LIKELY LIMIT THE
INLAND EXTENT OF LOW STRATUS. S TO SW WINDS WILL PERSIST OVERNIGHT
GENERALLY 4 TO 8 KT, INCREASING LATER THURSDAY TO 10-15 KT WITH
GUSTS TO 25 KT LATE THURSDAY INTO EARLY FRIDAY MORNING AS A FRONTAL
SYSTEM BRINGS BREEZY WINDS ALONGSIDE MVFR CEILINGS IN WIDESPREAD
RAIN.
15
MARINE
A STRONGER FRONTAL SYSTEM APPROACHING THE AREA WATERS
THURSDAY WILL RESULTING IN INCREASING SOUTHERLY WINDS AND SEAS.
THURSDAY NIGHT INTO FRIDAY. A DEVELOPING SURFACE LOW NEAR 990
MB WILL REACH THE OFFSHORE WATERS LATE FRIDAY NIGHT AND MOVE
INTO VANCOUVER ISLAND LATER SATURDAY. THE ASSOCIATED FRONT WILL
MOVE THROUGH THE WATERS SATURDAY NIGHT. THE PATTERN WILL REMAIN
ACTIVE INTO NEXT WEEK. GALE WARNINGS HAVE BEEN ISSUED FOR ALL
WATERS EXCEPT PUGET SOUND/HOOD CANAL. EVEN WHERE SUSTAINED WINDS
DON'T REACH GALE CRITERIA, PROBABILITIES ARE HIGH THAT FREQUENT
GUSTS FROM 35 TO 45 KNOTS WILL BE PRETTY COMMON. SEAS 7 TO 9
FEET TONIGHT WILL BUILD TO 10 TO 14 FEET THURSDAY AND AS HIGH
AS 20 FEET THURSDAY NIGHT. SEAS ARE EXPECTED TO SUBSIDING SLOWLY
FRIDAY INTO SATURDAY ENDING UP AROUND 10 TO 13 FEET SUNDAY.
A SECOND DEVELOPING SYSTEM ARRIVING SATURDAY CONTINUES TO SHOW
THE POTENTIAL TO PRODUCE GALE FORCE WINDS OVER ALL THE WATERS.
WINDS EASING THE LATTER HALF OF THE WEEKEND INTO MONDAY.
HYDROLOGY
THE STORM SYSTEM THURSDAY THROUGH FRIDAY IS
EXPECTED TO HAVE TWO TO FOUR INCHES OF RAIN FOR THE OLYMPICS AND
CASCADES WITH SNOW LEVELS STARTING OUT AT 5000 TO 6000 FEET.
THE SNOW LEVELS WILL DROP TO AROUND 3500 FEET DURING THE LATTER
PART OF THE PRECIPITATION. THIS WILL DRIVE UP ALL RIVERS, BUT
EVEN THE MOST FLOOD PRONE SKOKOMISH RIVER LOOKS LIKE IT WILL
CREST A BIT BELOW ACTION STAGE. ADDITIONAL RAINFALL INTO NEXT
WEEK COULD PUSH THE SKOKOMISH RIVER CLOSER TO FLOOD STAGE AS
MORE ATMOSPHERIC RIVER ACTIVITY WILL RETURN TO WESTERN
WASHINGTON AND AREA RIVERS BEGIN TO RISE AGAIN.
IN ADDITION, RAIN RATES THURSDAY NIGHT THROUGH FRIDAY MAY BE HIGH
ENOUGH TO BRING A RISK OF URBAN/SMALL STREAM NUISANCE FLOODING,
ESPECIALLY IN AREAS WITH POOR/BLOCKED DRAINAGE (LEAVES WILL BE
FALLING DURING THIS EVENT DUE TO GUSTY WINDS). THESE RAINFALL RATES
WILL ALSO POSE RISKS TO THE MORE VULNERABLE BURN SCARS IN TERMS OF
FLASH FLOODING AND DEBRIS FLOWS.
JBB
SEW WATCHES/WARNINGS/ADVISORIES
WA...HIGH SURF ADVISORY FROM 6 PM THURSDAY TO 8 AM PDT FRIDAY FOR
GRAYS HARBOR COUNTY COAST-NORTHERN WASHINGTON COAST.
PZ...SMALL CRAFT ADVISORY FROM 6 AM TO 11 PM PDT THURSDAY FOR GRAYS
HARBOR BAR.
GALE WARNING FROM NOON THURSDAY TO 5 AM PDT FRIDAY FOR COASTAL
WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-
COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10
NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10
TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT
GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE
TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT
GRENVILLE TO CAPE SHOALWATER OUT 10 NM-WEST ENTRANCE U.S.
WATERS STRAIT OF JUAN DE FUCA.
GALE WARNING FROM 6 PM THURSDAY TO 11 AM PDT FRIDAY FOR
ADMIRALTY INLET-CENTRAL U.S. WATERS STRAIT OF JUAN DE
FUCA-EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-
NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.
SMALL CRAFT ADVISORY FROM 6 AM TO NOON PDT THURSDAY FOR
COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO
60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND
OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT
GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO
POINT GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT
GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS
FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM.
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