522
FXUS66 KSEW 240313
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
813 PM PDT THU OCT 23 2025
SYNOPSIS
A STRONG FRONT WILL BEGIN TO IMPACT WESTERN
WASHINGTON TONIGHT AND INTO FRIDAY, BRINGING GUSTY WINDS AND
WIDESPREAD RAIN. A SECOND STRONG SYSTEM WILL BE RIGHT ON ITS
HEELS FOR SATURDAY, RESULTING IN ANOTHER ROUND OF RAINFALL AND
WINDY CONDITIONS. SNOW LEVELS DROPPING SUNDAY MAY ALLOW FOR THE
POSSIBILITY OF SNOW ON ALL THE PASSES. THE ACTIVE PATTERN WILL
CONTINUE NEXT WEEK AS ADDITIONAL SYSTEMS PASS THROUGH THE AREA.
UPDATE
SHOWERS CONTINUE THIS EVENING ACROSS THE NORTHERN HALF
OF WESTERN WA. HI-RES GUIDANCE STILL SHOWS A STEADIER RAIN
PICKING UP LATER TONIGHT INTO FRIDAY MORNING. A COUPLE OF THE
HEAVIER RAIN BANDS MAY BE ABLE TO PRODUCE RAINFALL RATES UP TO
0.50 INCH/HOUR (PARTICULARLY IN THE OLYMPICS AND CASCADES).
WINDS WILL ALSO PICK UP TONIGHT (SOME SPOTS HAVE ALREADY SEEN
GUSTS OVER 30 MPH, PARTICULARLY ALONG THE COAST AND AT WHIDBEY
ISLAND). FORECAST BELOW REMAINS ON TRACK (WITH AN UPDATED
AVIATION SECTION).
HPR
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/
CURRENT
SATELLITE CONTINUES TO SHOW W WA MOSTLY ENGULFED IN CLOUDS.
BREAKS ARE STILL PRESENT, BUT DEFINITELY FEWER AND THINNER THAN
THOSE THIS MORNING. RADAR STARTING TO SEE SOME WEAKER PRE-
FRONTAL ECHOES MAKING IT TO THE COAST. CURRENT OBS NOT SHOWING
ANYTHING MAKING IT TO THE GROUND YET THERE...HOWEVER SOME
SPRINKLES OR A LIGHT SHOWER CANNOT BE RULED OUT FROM THESE
ECHOES.
THESE PRE-FRONTAL BANDS A GOOD SIGN THAT FORECAST REMAINS ON
TRACK...WITH THE COAST LIKELY TO SEE MAIN PRECIP THIS EVENING WHILE
INTERIOR LOCATIONS WILL LIKELY NEED TO WAIT UNTIL EITHER THE
OVERNIGHT PERIOD OR EARLY FRIDAY MORNING TO SEE ANY PRECIP. INSTEAD,
THE MAIN CONCERN FOR THE INTERIOR WILL BE THE INCREASING WIND SPEEDS
TONIGHT...ESPECIALLY IN THE ISLANDS AND THE WESTERN PORTIONS OF
WHATCOM AND SKAGIT COUNTIES. AT THIS TIME, NBM MIGHT BE A LITTLE
OVERDONE ON WIND SPEEDS HERE AND HAVE PARED IT BACK LEANING MORE
TOWARD UWWRF4KM...THIS BLEND WILL KEEP WIND SPEEDS JUST BELOW
HEADLINE CRITERIA WHICH SHOULD BETTER REFLECT THE EXPECTED WIND
SPEEDS/GUSTS. THIS WILL NOT RULE OUT ISOLATED LOCATIONS SEEING
SPEEDS AND GUSTS THAT WOULD MEET WIND ADVISORY CRITERIA, BUT
ULTIMATELY THE TREND IN MODEL SOLUTIONS SUGGESTS A MORE BORDERLINE
TO JUST UNDER SORT OF EVENT AND THIS TWEAK TO THE FORECAST FALLS
MORE IN LINE WITH THIS THINKING.
IT IS ALSO WORTH A MENTION THAT SEAS GETTING UP TO AROUND 20 FT THIS
EVENING AND TONIGHT BEFORE SUBSIDING FRIDAY COULD RAISE SOME HIGH
SURF CONCERNS. ALTHOUGH WAVES MAY FALL JUST SHORT OF CRITERIA,
COASTAL ACTIVITIES SUCH AS CLAM DIGGING WILL BE IMPACTED AND THUS,
GIVEN THIS UNIQUE MIXTURE OF CIRCUMSTANCES, INHERITED HIGH SURF
ADVISORY LOOKS GOOD AND WILL REMAIN IN PLACE.
WINDS EASE FRIDAY ALTHOUGH PRECIP WILL HANG ON FOR THE MAJORITY OF
THE DAY. QPF VALUES FOR LOCATIONS AROUND PUGET SOUND, BOTH EAST AND
WEST SIDES, SEE PRECIP VALUES RANGING FROM A HALF-INCH TO ONE INCH
FOR THE EVENT WHILE LOCATIONS ALONG THE COAST AND IN THE CASCADE
FOOTHILLS SEEING AROUND AN INCH TO AN INCH-AND-A-HALF. HIGHER
ELEVATIONS COULD SEE AMOUNTS UP TO 2 INCHES.
ACTIVITY DIMINISHES SOMEWHAT FRIDAY NIGHT JUST IN TIME FOR THE NEXT
SYSTEM TO MOVE INTO THE AREA. FRIDAY NIGHT DOES SEE SNOW LEVELS
START TO FALL INTO THE 4000 FT RANGE AND THIS WILL COME INTO PLAY
FOR THE END OF THE SHORT TERM PERIOD. AT THIS POINT IN THE FORECAST
HOWEVER, THE NEXT WAVE OF RAIN AND WINDY CONDITIONS MOVES INTO W WA.
RAIN FROM THIS SYSTEM WILL BE DRAWN OUT OVER A LONGER PERIOD OF
TIME...ALL OF BOTH SATURDAY AND SUNDAY...BUT WITH ONLY SLIGHTLY
HIGHER QPF VALUES. LOCATIONS AROUND PUGET SOUND WILL SEE SIMILAR
RAINFALL AMOUNTS WHILE REMAINING LOCATIONS MAY SEE AN INCREASE OF
AROUND A HALF INCH TO AN INCH IN THE RANGES EXPECTED WITH THE FRIDAY
SYSTEM. WINDS FOR SATURDAY LOOK TO SEE A LITTLE BIT OF AN INCREASE
FROM WHAT IS EXPECTED FROM THE INITIAL FRIDAY SYSTEM. THAT SAID,
WITH FRIDAY BEING A VERY BORDERLINE INSTANCE, FELT THAT A WAIT-AND-
SEE APPROACH WOULD BE THE BEST WAY TO GO WHEN IT CAME TO WIND
HEADLINES FOR THIS SECONDARY SYSTEM. IF WINDS TONIGHT AND FRIDAY DO
NOT PAN OUT...THEN THAT WOULD CERTAINLY LOWER CONFIDENCE IN ANY
HEADLINES FOR SATURDAY. CONVERSELY, SHOULD FRIDAY WINDS OVER-PERFORM,
SATURDAY WOULD BE A SLAM-DUNK.
SUNDAY SEES POPS EASE SLIGHTLY, BUT GENERAL TROUGHINESS OVER THE
AREA ENSURES THAT SHOWERS WILL REMAIN IN PLACE FOR THE CLOSING
STAGES OF THE WEEKEND. MODELS CONTINUING TO SHOW GOOD CONSISTENCY
WITH THE SNOW LEVELS LOWERING TO 3000-3500 FEET SUNDAY, HOWEVER BY
THIS POINT PRECIP WILL TRANSITION TO MORE SHOWERY AND DISORGANIZED.
AS SUCH, IT IS POSSIBLE STEVENS PASS AND MOUNT BAKER GET 4 TO 8
INCHES OF NEW SNOW SUNDAY THROUGH MONDAY MORNING WITH HIGHER AMOUNTS
ON MOUNT RAINIER. SNOQUALMIE PASS COULD ALSO SEE A COUPLE OF INCHES
OF ACCUMULATION. AT THIS TIME, WILL REFRAIN FROM ANY POTENTIAL
WINTER HEADLINES THERE.
DAYTIME HIGHS WILL REMAIN MILD ALTHOUGH COOLING FROM DAY TO DAY
COINCIDING WITH EACH SYSTEM'S PASSAGE. TODAY WILL BE THE WARMEST
THANKS TO A WARM FRONT NICKING THE NW CORNER OF THE CWA WITH HIGHS
GENERALLY IN THE LOWER TO MID 60S. FROM HERE, HIGHS COOL A LITTLE
BIT DAY BY DAY, WITH HIGHS FRIDAY IN THE UPPER 50S TO LOWER 60S AND
SATURDAY IN THE LOWER TO MID 50S. SUNDAY SEES MOST LOWLAND LOCATIONS
IN THE LOWER 50S.
18
LONG TERM /SUNDAY THROUGH THURSDAY/
A HIGH DEGREE OF
UNCERTAINTY REMAINS WHEN IT COMES TO THE REMAINDER OF THE
FORECAST PERIOD STRETCHING MONDAY THROUGH WEDNESDAY. OPERATIONAL
DETERMINISTIC MODELS CONTINUE TO DISPLAY VARYING DEGREES OF
RIDGING TRYING TO SET UP OVER THE W US, WHICH, DEPENDING ON HOW
FAR NORTHWARD IT BUILDS, WOULD ALLOW FOR DRY CONDITIONS FROM
TIME TO TIME OVER THE PACNW. IT IS CERTAINLY WORTH NOTING THAT
EVEN HERE, THERE ARE SIGNIFICANT DIFFERENCES IN THE THE GFS AND
ECMWF WHERE THERE IS NO CLEAR SIGNAL AS TO WHICH DAYS WILL BE
WET AND WHICH ONES WILL BE DRY. ENSEMBLE SOLUTIONS ONLY MUDDY
THE SITUATION FURTHER, WITH JUST AS MANY MEMBERS ADVERTISING DRY
CONDITIONS AS THOSE SHOWING WET SOLUTIONS. GIVEN THE TIME OF
YEAR, INCLINED TO SIDE MORE WITH WETTER SOLUTIONS THAN DRY...AND
CURRENT NBM SEEMS CONTENT TO DO THE SAME. WILL CONTINUE TO
ADVERTISE THIS GENERALLY ACTIVE PERIOD UNTIL FORECAST COMES INTO
BETTER FOCUS/ALIGNMENT.
18
AVIATION
MOSTLY VFR WITH LIGHT SHOWER ACTIVITY NORTH OF THE PUGET
SOUND THIS EVENING AND MVFR CEILINGS PERSISTING ALONG THE PACIFIC
COAST. WIDESPREAD RAINFALL WILL SPREAD INLAND LATE TONIGHT INTO
FRIDAY MORNING, REMAINING STEADY THROUGHOUT MUCH OF THE DAY BEFORE
BREAKING UP FRIDAY EVENING. MVFR CONDITIONS ARE SLATED TO BECOME
MORE WIDESPREAD ON FRIDAY UNDER HEAVIER PRECIPITATION, LIMITING
VISIBILITY AND LOWERING CIGS DOWN AT TIMES. WINDS GENERALLY S TO SW
THIS EVENING WILL PICK UP AS A FRONTAL SYSTEM CROSSES THE REGION,
WITH WINDS REACHING 10 TO 20 KT AND GUSTS AS STRONG AS 30 TO 35 KT
BETWEEN KPAE AND KBLI. SURFACE WINDS WILL PEAK MID MORNING
AND GRADUALLY TAPER THROUGHOUT THE LATE MORNING AND AFTERNOON FRIDAY.
KSEA... VFR CONDITIONS THROUGH THE EARLY MORNING HOURS FRIDAY BEFORE
WIDESPREAD RAIN FILLS IN OVER THE TERMINAL BY THE MID MORNING,
BRINGING MVFR CONDITIONS AT TIMES IN LOWER VISIBILITIES WITH
CEILINGS HOVERING BETWEEN MVFR AND LOW END VFR. SURFACE WINDS
GENERALLY S TO SW THIS EVENING 4 TO 8 KT WILL INCREASE TO 10 TO 15
KT WITH GUSTS UP TO 25 KT AS A FRONTAL SYSTEM MOVES INLAND. WINDS
WILL GRADUALLY TAPER OFF THROUGHOUT THE AFTERNOON HOURS FRIDAY
ALONGSIDE DECREASING PRECIPITATION.
15
MARINE
A STRONG FRONTAL SYSTEM WILL ENTER THE COASTAL WATERS
TONIGHT BEFORE MOVING THROUGH THE REMAINING AREA WATERS FRIDAY.
A DEVELOPING SURFACE LOW WILL REACH THE OFFSHORE WATERS LATE
FRIDAY NIGHT AND MOVE INTO VANCOUVER ISLAND AND SOUTHERN BRITISH
COLUMBIA LATE SATURDAY INTO SATURDAY NIGHT. THE PATTERN WILL
REMAIN ACTIVE INTO NEXT WEEK.
GALE FORCE WINDS DEVELOPING OVER THE COASTAL WATERS THIS EVENING
THEN SPREADING INLAND FOR THE NORTHERN PORTION OF THE INLAND WATERS
INCLUDING THE STRAIT OF JUAN DE FUCA TONIGHT. WINDS EASING BY LATE
FRIDAY MORNING. GALES ARE POSSIBLE ACROSS ALL THE WATERS EITHER
SATURDAY OR SATURDAY NIGHT WITH THE SECONDARY FRONT. CURRENT GALE
WATCH THERE LOOKS SOLID AND WILL OPT TO LEAVE THAT ALONE FOR NOW.
WINDS SETTLING DOWN SUNDAY INTO THE FIRST PART OF NEXT WEEK.
SEAS BUILDING TO AS HIGH AS 20 FEET LATER TODAY INTO TONIGHT.
SEAS SUBSIDING FRIDAY INTO THE 12 TO 16 FOOT RANGE AND TO 10 TO
13 FEET FRIDAY NIGHT. SEAS BUILDING AGAIN SATURDAY INTO SATURDAY
NIGHT PEAKING OUT AGAIN AROUND 20 FEET. SEAS SUBSIDING SUNDAY
DROPPING BELOW 10 FEET FOR THE FIRST PART OF NEXT WEEK.
FELTON/18
HYDROLOGY
FORECAST PRECIPITATION AMOUNTS FOR THE OLYMPICS
TONIGHT THROUGH FRIDAY TIMEFRAME REMAINING IN THE 2 TO 3
INCH RANGE WITH LOCAL AMOUNTS TO 4 INCHES. SNOW LEVELS NEAR 7000
FEET WITH THE ONSET OF THE PRECIPITATION WILL SLOWLY LOWER TO
NEAR 6000 FEET FRIDAY. THIS WILL HELP KEEP SOME OF THE
PRECIPITATION IN THE OLYMPICS IN THE FORM OF SNOW DECREASING THE
AMOUNT OF RUNOFF. CURRENT HYDROGRAPH FOR THE SKOKOMISH RIVER
HAS THE RIVER CRESTING FRIDAY AFTERNOON NEAR ACTION STAGE.
ACTION STAGE IS A FOOT AND A HALF BELOW FLOOD STAGE. THE
REMAINDER OF THE RIVERS IN WESTERN WASHINGTON WILL RISE SHARPLY
LATER FRIDAY WITH TWO TO THREE INCHES OF PRECIPITATION FORECAST
FOR THE CASCADES AND THE COAST AND A HALF TO ONE AND A HALF
INCHES IN THE LOWLANDS. RIVERS STARTING FROM VERY LOW LEVELS SO
EVEN THE WITH SHARP RISES LATE FRIDAY THE RIVERS WILL BE WELL
WITHIN THEIR BANKS.
THE MAIN CONCERN FRIDAY INTO FRIDAY NIGHT IS THE 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). RAINFALL RATES WILL ALSO POSE RISKS TO THE
MORE VULNERABLE BURN SCARS IN TERMS OF FLASH FLOODING AND
DEBRIS FLOWS.
ADDITIONAL RAINFALL EXPECTED NEXT WEEK WITH THE SKOKOMISH RIVER
BEING THE MAIN CONCERN. FELTON/18
SEW WATCHES/WARNINGS/ADVISORIES
WA...HIGH SURF ADVISORY UNTIL 8 AM PDT FRIDAY FOR GRAYS HARBOR
COUNTY COAST-NORTHERN WASHINGTON COAST.
PZ...SMALL CRAFT ADVISORY UNTIL 6 PM PDT FRIDAY FOR GRAYS HARBOR
BAR.
GALE WARNING UNTIL 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 WATCH FROM SATURDAY MORNING THROUGH LATE SATURDAY NIGHT
FOR ADMIRALTY INLET-CENTRAL U.S. WATERS STRAIT OF JUAN DE
FUCA-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-
EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-NORTHERN
INLAND WATERS INCLUDING THE SAN JUAN ISLANDS-WEST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
GALE WARNING UNTIL 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.
GALE WATCH FROM SATURDAY EVENING THROUGH LATE SATURDAY NIGHT
FOR PUGET SOUND AND HOOD CANAL.
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