766
FXUS66 KSEW 221104
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
404 AM PDT WED OCT 22 2025
SYNOPSIS
WEAK SYSTEM MOVING THROUGH WESTERN WASHINGTON THIS AFTERNOON AND
EVENING. MUCH STRONGER SYSTEM ARRIVES FRIDAY WITH RAIN AND
WINDY CONDITIONS BEGINNING THURSDAY NIGHT AHEAD OF THE FRONT.
ANOTHER STRONG SYSTEM MOVING QUICKLY EAST WILL REACH THE AREA
SATURDAY FOR ANOTHER ROUND OF RAIN AND WIND. COOLER AIR MASS
BEHIND THE FRONT COULD DROP SNOW LEVELS BELOW ALL OF THE PASSES
SUNDAY. THE ACTIVE PATTERN WILL CONTINUE INTO NEXT WEEK.
SHORT TERM /TODAY THROUGH FRIDAY NIGHT/
SATELLITE IMAGERY SHOWS CLEAR SKIES OVER WESTERN WASHINGTON. FOG
HAS FORMED IN THE CENTRAL AND SOUTHERN PUGET SOUND AS WELL AS
ALONG THE STRAIT OF JUAN DE FUCA IN THE LAST COUPLE OF HOURS.
TEMPERATURES AT 3 AM/10Z WERE MOSTLY IN THE 40S WITH THE COLDER
LOCATIONS IN THE MID TO UPPER 30S.
SURFACE GRADIENTS INCREASING AS A WEAKENING FRONT APPROACHES
WESTERN WASHINGTON THIS MORNING. THIS WILL STIR THINGS UP ENOUGH
TO DISSIPATE THE SHALLOW FOG LAYER. RAIN ARRIVING ON THE COAST
MIDDAY WITH THE RAIN SPREADING INLAND MID AFTERNOON. THE FRONT
BY THIS POINT WILL NOT HAVE MUCH LEFT TO IT SO ONLY EXPECTING A
BRIEF, 2 OR 3 HOURS, OF RAIN JUST AHEAD OF THE FRONT. A LITTLE
PUSH OF WARMER AIR AHEAD OF THE FRONT WILL GET SOME LOCATIONS
INTO THE LOWER 60S WITH THE REMAINDER OF THE AREA IN THE UPPER
50S.
FRONT MOVING THROUGH THE PUGET SOUND AREA EARLY EVENING AND
INTO THE CASCADES WELL BEFORE MIDNIGHT. SATELLITE IMAGERY
SHOWING NOTHING IN THE WAY OF COOLER AIR BEHIND THE FRONT MAKING
FOR LITTLE POST FRONTAL SHOWER ACTIVITY. CLOUD COVER OVERNIGHT
KEEPING LOWS IN THE MID TO UPPER 40S.
THURSDAY NOW LOOKING LIKE A DRY DAY ESPECIALLY FOR THE SOUTHERN
PORTION OF THE INTERIOR. FRONTAL SYSTEM APPROACHING THE COAST
THURSDAY AFTERNOON WITH THE LEADING WARM FRONT WEAKENING AND
MOVING INTO SOUTHERN BRITISH COLUMBIA IN THE AFTERNOON. THIS
PUTS WESTERN WASHINGTON IN THE WARM SECTOR AND WITH THE
WEAKENING WARM FRONT JUST SOME MIDDLE LEVELS CLOUDS OVER MOST OF
THE AREA. COULD STILL SEE A BRIEF SHOWER OUT OF THE MIDDLE
LEVEL DECK. THE BEST CHANCE FOR A LITTLE RAIN WILL BE ALONG THE
NORTH COAST. HIGHS THURSDAY IN THE LOWER TO MID 60S.
TRAILING COLD FRONT SLOWING DOWN THURSDAY NIGHT AS THE UPPER
LEVEL TROUGH BEHIND THE FRONT DIGS SOUTH BETWEEN 130-135W. WINDS
PICKING UP OVERNIGHT ALONG THE COAST AND IN THE NORTHWEST
INTERIOR WITH GUSTS IN THE 40 TO 45 MPH RANGE LIKELY. RAIN WILL
BE SLOW TO ARRIVE WITH THE SLOWING FRONT. RAIN NOT GETTING EAST
OF PUGET SOUND UNTIL AFTER MIDNIGHT. LOWS A COUPLE OF DEGREES
EITHER SIDE OF 50.
UPPER LEVEL TROUGH CONTINUING TO DIG OFFSHORE WHICH WILL STALL
THE FRONT OVER WESTERN WASHINGTON FRIDAY MAKING FOR A WET AND
WINDY DAY. JET AIMED INTO THE CENTRAL OREGON COAST AND MODELS
SHOW HIGHEST IVT VALUES SOUTH OF THE AREA SO EVEN THOUGH THE
FRONT WILL STALL WESTERN WASHINGTON WILL NOT GET THE HIGHEST
RAINFALL AMOUNTS OUT OF THIS SYSTEM. IN GENERAL A HALF TO AN
INCH OF RAIN OVER THE INTERIOR WITH ONE TO TWO ( MAYBE 2.5
INCHES FAR NORTH COAST ) ALONG THE COAST AND IN THE CASCADES.
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.
FRONT MOVING THROUGH FRIDAY EVENING WITH RAIN TURNING TO SHOWERS
AND WINDS EASING. FELTON
LONG TERM /SATURDAY THROUGH TUESDAY/
MODELS HAVING TROUBLE
WITH THE PLACEMENT OF THE NEXT SYSTEM. THIS FRONT HAS A DEVELOPING
SURFACE LOW NEAR 990 MB. WILL HAVE TO KEEP AN EYE ON THIS ONE
WITH A FEW OF THE ENSEMBLE SOLUTIONS SHOWING 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. SNOW LEVELS DROPPING
BELOW THE HIGHER PASSES SATURDAY INTO SATURDAY NIGHT WITH THE
POTENTIAL FOR SNOW LEVELS TO BE BELOW ALL OF THE PASSES BY
SUNDAY MORNING. NOTHING ORGANIZED MOVING INTO WESTERN WASHINGTON
SUNDAY BUT COOL UPPER LEVEL TROUGH WILL PRODUCE PLENTY OF
SHOWERS DROPPING A FEW INCHES OF SNOW ABOVE 3000 FEET. WHILE THE
OPERATIONAL RUNS SHOW A BIT OF A BREAK MONDAY THE ENSEMBLE
SOLUTIONS TELL A DIFFERENT STORY KEEPING LIKELY POPS IN THE
FORECAST. SOLUTIONS BECOME VERY INCONSISTENT TUESDAY MAKING FOR
A LOW CONFIDENCE FORECAST. FELTON
AVIATION
SOUTHWEST FLOW ALOFT WILL INCREASE AS A WEAK FRONT MOVES ONSHORE AND
DISSIPATES LATE TODAY. THE LOW LEVEL FLOW IS LIGHT OFFSHORE TURNING
SOUTHERLY LATE THIS MORNING. LIGHT SURFACE FLOW AND SURFACE BASED
INVERSIONS HAVE LED TO THE FORMATION OF IFR/LIFR FOG AND STRATUS
AROUND PORTIONS OF THE PUGET SOUND LOWLANDS THIS MORNING. THE LOW
CLOUDS WILL ERODE BY AROUND MID-MORNING AS HIGH AND MID LEVEL CLOUDS
BEGIN TO INCREASE AHEAD THE APPROACHING FRONT. CEILINGS WILL LOWER
TO MVFR IN LIGHT RAIN ALONG THE COAST LATE THIS AFTERNOON WITH SAID
CONDITIONS SPREADING TO INTERIOR AREAS MAINLY NORTH OF KSEA BY THIS
EVENING.
KSEA...LIFR STRATUS IS LIKELY TO REMAIN AT OR IN THE IMMEDIATE
VICINITY OF THE TERMINAL THROUGH MID-MORNING. A COMBINATION OF
INCREASING SOUTHERLY WIND AND INCREASING HIGH LEVEL CLOUDS SHOULD
HELP ERODE THE LOW CLOUDS 16Z-18Z. VFR IN INCREASING CLOUDS IS
EXPECTED THEREAFTER WITH A FEW SHOWERS BY EARLY EVENING, BUT MOST
PRECIPITATION WITH THIS SYSTEM IS EXPECTED TO REMAIN NORTH AND WEST
OF TERMINAL. SURFACE WINDS LIGHT AND VARIABLE EARLY BECOMING
SOUTHERLY AND RISING TO 8 TO 12 KNOTS TOWARD MIDDAY. 27
MARINE
A WEAK SYSTEM WILL MOVE THROUGH THE WATERS THIS AFTERNOON AND
EVENING. A STRONGER FRONTAL SYSTEM WILL ARRIVE 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 WATCH IN EFFECT FOR THURSDAY AFTERNOON INTO FRIDAY MORNING
FOR THE COASTAL WATERS AS WELL AS THE ENTRANCES TO THE STRAIT OF
JUAN DE FUCA, ADMIRALTY INLET AND THE NORTHERN INLAND WATERS.
THE SYSTEM ARRIVING SATURDAY HAS THE POTENTIAL TO PRODUCE GALE
FORCE WINDS OVER ALL THE WATERS. WINDS EASING THE LATTER HALF OF
THE WEEKEND INTO MONDAY.
SEAS 8 TO 10 FEET TODAY SUBSIDING A LITTLE TONIGHT THEN BUILDING
TO 10 TO 14 FEET THURSDAY AND AS HIGH AS 20 FEET THURSDAY NIGHT.
SEAS SUBSIDING SLOWLY FRIDAY INTO SATURDAY ENDING UP AROUND 10
TO 13 FEET SUNDAY. FELTON
HYDROLOGY
EVEN WITH THE TWO TO FOUR INCHES OF RAIN FORECAST FOR THE
OLYMPICS LATER THURSDAY NIGHT THROUGH FRIDAY THE FLOODING RISK
ON THE SKOKOMISH RIVER CONTINUES TO DIMINISH. SNOW LEVELS IN THE
6000-7000 FOOT WILL HELP KEEP SOME OF THE PRECIPITATION IN THE
OLYMPICS IN THE FORM OF SNOW INSTEAD OF RUNOFF. OTHER RIVER
ACROSS WESTERN WASHINGTON WILL SEE RISES BUT REMAIN WELL BELOW
FLOOD STAGE. ADDITIONAL RAINFALL INTO NEXT WEEK COULD PUSH THE
SKOKOMISH RIVER TO AT LEAST ACTION STAGE.
OUTSIDE OF THE RIVER, 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). RISKS TO BURN SCARS WILL ALSO NEED TO BE MONITORED
THROUGH THIS EVENT, BUT CURRENTLY THE RISK APPEARS TO BE BELOW
ANY ALERT LEVELS. FELTON
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 PM PDT THIS AFTERNOON 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-GRAYS HARBOR BAR-
WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM PDT THURSDAY FOR GRAYS
HARBOR BAR.
GALE WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY MORNING FOR
COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10
NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE
OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER OUT 10 NM-WEST ENTRANCE U.S. WATERS STRAIT OF
JUAN DE FUCA.
GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
ADMIRALTY INLET-EAST ENTRANCE U.S. WATERS STRAIT OF JUAN
DE FUCA-NORTHERN INLAND WATERS INCLUDING THE SAN JUAN
ISLANDS.
GALE WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY NIGHT
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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