097
FXUS66 KSEW 221654
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
954 AM PDT WED OCT 22 2025
UPDATE
NO CHANGES TO THE OVERALL FOREACAST. PLEASE SEE THE
AVIATION AND HYRDOLOGY SECTIONS BELOW FOR UPDATES TO THOSE
FORECASTS. |
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/
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 /FRIDAY NIGHT 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 THIS EVENING. THE LOW LEVEL FLOW
TURNING SOUTHERLY THIS MORNING. LIGHT SURFACE FLOW AND SURFACE
BASED INVERSIONS HAVE LED TO THE FORMATION OF LIFR FOG AND
STRATUS ACROSS ALL TERMINALS THIS MORNING WITH THE EXCEPTION OF
HQM. THE LOW CLOUDS WILL ERODE AROUND MID-DAY 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 FOG/STRATUS WILL REMAIN AT TERMINAL THROUGH MID-DAY. A
COMBINATION OF INCREASING SOUTHERLY WIND AND INCREASING HIGH LEVEL
CLOUDS SHOULD HELP ERODE THE LOW CLOUDS AROUND 18Z. VFR AND
INCREASING MID TO HIGH CLOUDS ARE 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 BECOMING SOUTHERLY AND RISING TO 8 TO 12 KNOTS TOWARD
MIDDAY.
MCMILLIAN
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.
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.
FELTON/JBB
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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