510
FXUS66 KSEW 150303
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
802 PM PDT TUE APR 14 2026
SYNOPSIS
A FRONTAL SYSTEM WILL CONTINUE TO MOVE THROUGH
WESTERN WASHINGTON TONIGHT WITH LOWLAND RAIN, BREEZY WINDS, AND
MOUNTAIN SNOWFALL. POST FRONTAL UNSETTLED CONDITIONS WILL CONTINUE
ON WEDNESDAY. DRIER, COOL WEATHER THURSDAY AND FRIDAY BEFORE A
SYSTEM WILL APPROACH THE AREA OFFSHORE OVER THE WEEKEND.
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/
BOTH LATEST SATELLITE
AND RADAR CLEARLY SHOW THE BACK EDGE OF THE CURRENT FRONT PASSING
OVER THE OLYMPIC PENINSULA, WITH THE NORTHWEST CORNER OF THE
LANDMASS ALREADY ENTERING INTO THE POST FRONTAL ENVIRONMENT. THIS
STILL MEANS THE MAJORITY OF W WA IS IN FOR A WET EVENING AND AT
LEAST SOME PART OF THE TONIGHT PERIOD...WITH THE CASCADES CHECKING
OUT LAST AS ACTIVITY THERE IS SLATED TO GO INTO EARLY WEDNESDAY
MORNING. WINDS HAVE EASED, ALLOWING FOR INHERITED WIND ADVISORIES TO
EXPIRE. BREEZY CONDITIONS AND OCCASIONAL GUSTS WILL STILL BE A THING
INTO TONIGHT...AND SO SOME ISOLATED WIND-RELATED IMPACTS WILL STILL
BE POSSIBLE...BUT THE THREAT FOR WIDESPREAD STRONG AND GUSTY WINDS
HAS LARGELY WRAPPED UP.
ALL ACCORDING TO PLAN, OR SO IT SEEMS, AS INHERITED FORECAST HANDLES
THIS WELL. THUS, NO NEED FOR ANY EVENING UPDATES. FOR ADDITIONAL
FORECAST DETAILS, PLEASE REFER TO THE PREVIOUS DISCUSSION SECTION
BELOW.
FROM PREVIOUS DISCUSSION...A FRONTAL SYSTEM CONTINUES TO MOVE ACROSS
WESTERN WASHINGTON THIS AFTERNOON. STEADY RAIN THROUGH THIS EVENING
WITH A BRIEF CONVERGENCE ZONE PROGRESSING ACROSS CENTRAL PUGET SOUND
TONIGHT. SOUTH WINDS WILL REMAIN BREEZY, PEAKING THIS AFTERNOON AND
EVENING. A WIND ADVISORY REMAINS IN EFFECT FOR THE GRAYS HARBOR
COUNTY COAST, AS WELL AS ADMIRALTY INLET AND EVERETT REGION, WITH
GUSTS OF 35 TO 45 MPH IN THESE AREAS. WINDS REMAIN BREEZY ELSEWHERE,
WITH GUSTS RANGING 25 TO 40 MPH. INCREASING FOLIAGE WILL MAKE TREES
MORE SUSCEPTIBLE TO DAMAGE, WHICH MAY RESULT IN LOCALIZED POWER
OUTAGES.
SNOW LEVELS AROUND 4000 FEET THIS AFTERNOON WILL FALL TO 1500
FEET BY WEDNESDAY MORNING, RESULTING IN SNOW FOR THE CASCADES
AND OLYMPICS, INCLUDING THE PASSES. SNOW WILL CONTINUE AT TIMES
FOR THE CASCADES THROUGH WEDNESDAY. TOTAL SNOWFALL AMOUNTS OF 8
TO 14 INCHES ARE EXPECTED FOR SNOQUALMIE AND STEVENS PASSES,
WITH LOCALLY HIGHER AMOUNTS NEAR 18" AROUND WHITE PASS AND MOUNT
BAKER. A WINTER STORM WARNING REMAINS IN EFFECT. SNOW WILL
SUBSIDE WEDNESDAY NIGHT.
AN UPPER LOW WILL MOVE ACROSS THE PACIFIC NORTHWEST ON
WEDNESDAY. THIS WILL RESULT IN COLDER TEMPERATURES ALOFT, AND
INCREASING INSTABILITY. SCATTERED SHOWERS WILL BE AROUND
WEDNESDAY, WITH THE THREAT FOR ISOLATED THUNDERSTORMS. THE
PROBABILITIES FOR THUNDERSTORMS PEAK BETWEEN 15 TO 25 PERCENT,
PRIMARILY DURING THE AFTERNOON. LIGHTNING, BREEZY WINDS, AS WELL
AS SMALL HAIL MAY ACCOMPANY ANY HEAVIER SHOWERS.
DRIER CONDITIONS WILL DEVELOP WEDNESDAY NIGHT AS CONDITIONS
BEGIN TO CLEAR FOR SOME AREAS. TEMPERATURES BY THURSDAY MORNING
WILL FALL INTO THE LOW TO MID 30S, RESULTING IN POTENTIAL FROST
CONCERNS. WILL ALSO NEED TO MONITOR FREEZE CONDITIONS FOR
PORTIONS OF SOUTH SOUND. OTHERWISE, INCREASING SUNSHINE IS
EXPECTED DURING THE AFTERNOON THURSDAY.
LONG TERM /FRIDAY THROUGH TUESDAY/
WEAK UPPER RIDGING BRINGS
DRIER CONDITIONS ON FRIDAY. WILL NEED TO MONITOR THE FROST
POTENTIAL ONCE AGAIN, MAINLY FROM OLYMPIA SOUTHWARDS FRIDAY AM.
AN UPPER LOW WILL TRACK TOWARDS THE WEST COAST OVER THE WEEKEND.
UNCERTAINTY REMAINS IN ENSEMBLES IN THE LOCATION OF THE UPPER
LOW BY SUNDAY, WHICH IMPACTS THE EASTWARD EXTENT OF
PRECIPITATION OVER THE WEEKEND. AT THIS TIME, THE HIGHEST
PROBABILITY FOR RAIN OVER THE WEEKEND IS ALONG THE OLYMPIC
PENINSULA, BUT PRECIPITATION CHANCES EXTEND THROUGH PUGET SOUND,
ESPECIALLY BY SUNDAY. THE BULK OF THE ENERGY THEN MOVES TOWARDS
CALIFORNIA BY EARLY NEXT WEEK, WHICH MAY RESULT IN DRIER
CONDITIONS FOR WESTERN WASHINGTON. HOWEVER, SLIGHT CHANCE OF
PRECIPITATION REMAINS IN THE FORECAST AT THIS TIME. A WARMING
TREND EXISTS OVER THE WEEKEND WITH HIGHS REACHING THE LOW TO MID
60S. JD
AVIATION
A FRONTAL SYSTEM IS CURRENTLY MOVING ACROSS WESTERN WASHINGTON THIS
EVENING. RAIN WILL CONTINUE ACROSS THE AREA THROUGH THE NEXT FEW
HOURS, WITH MOST OF THE RAIN DEPARTING AFTER 06Z TUE. MVFR CIGS
PREVAIL IN THE RAIN BUT SOME LOCATIONS ARE ALREADY BEGINNING TO SEE
IMPROVEMENT. EXPECTING BEHIND THE FRONT FOR MOST LOCATIONS TO HAVE
VFR CIGS WITH SCATTERED LOWER CLOUDS AT TIMES. SCATTERED SHOWERS
WILL MOVE IN ACROSS THE AREA OVERNIGHT INTO THE EARLY MORNING HOURS,
AND A CONVERGENCE ZONE IS EXPECTED TO DEVELOP BEHIND THE FRONT LATE
THIS EVENING AND DISSIPATE QUICKLY, AND THEN AGAIN ON WEDNESDAY. IT
WILL LIKELY START NORTH OF THE METRO THEN SLOWLY MOVE SOUTHWARD
DURING THE DAY WEDNESDAY. OUTSIDE OF THESE AREAS, EXPECTING MOSTLY
VFR CONDITIONS WITH A BROKEN CLOUD DECK FOR MUCH OF THE DAY. IN
THESE SHOWERS AND THE CONVERGENCE ZONE, THERE WILL BE A 15-25%
CHANCE FOR SOME OF THESE TO BE THUNDERSTORMS (HIGHEST PROBABILITIES
WEDNESDAY AFTERNOON), BUT CURRENTLY THERE IS NOT HIGH ENOUGH
CONFIDENCE TO INCLUDE THIS IN MOST OF THE TAFS AT THIS TIME.
SOUTHWEST WINDS 10-20 KT WITH GUSTS 20-30 KT WILL THIS EVENING UNTIL
THE FRONT MOVES THROUGH. WINDS WILL GRADUALLY TAPER OVERNIGHT INTO
WEDNESDAY BECOMING SOUTH TO SOUTHWEST 5-10 KT THROUGH THE OVERNIGHT
PERIOD. KPAE MAY TEMPORARILY CHANGE TO N BETWEEN AROUND 03-12Z TUE,
AND THEN AGAIN AFTER 20-23Z AS ANOTHER CONVERGENCE AREA DEVELOPS.
THERE REMAINS SOME UNCERTAINTY AS TO HOW FAR SOUTH IT MAY GO.
KSEA...MVFR CONDITIONS CONTINUE WITH LOW CEILINGS AND TEMPORARY
REDUCTIONS IN VISIBILITY IN LIGHT TO MODERATE RAIN. RAIN WILL CEASE
THIS EVENING BEHIND THE FRONTAL PASSAGE AT AROUND 03-05Z TUE. CLOUDS
SHOULD LIFT AND BREAK APART FOR LOW-END VFR CONDITIONS. MVFR
CONDITIONS ARE THEN FAVORED TO DEVELOP EARLY WEDNESDAY MORNING
BEFORE VFR CONDITIONS RETURN LATE-MORNING AND THROUGH THE REMAINDER
OF THE DAY WEDNESDAY. SCATTERED SHOWERS WILL CONTINUE THROUGHOUT THE
DAY IN THE VICINITY OF THE TERMINAL. A POST-FRONTAL CONVERGENCE ZONE
IS FAVORED TO DEVELOP OVERNIGHT INTO WEDNESDAY, BUT WILL LIKELY STAY
NORTH OF THE TERMINAL UNTIL LATER IN THE DAY ON WEDNESDAY. 15-25%
CHANCE OF THUNDER AS WELL ON WEDNESDAY, THROUGH CURRENTLY CONFIDENCE
TOO LOW TO INCLUDE IN THE TAF.
S WINDS 12-15 KT WITH GUSTS 25-30 KT WILL CONTINUE UNTIL AROUND 06Z
WED, AFTER WHICH WINDS WILL EASE AND BEGIN TO TURN MORE SE
OVERNIGHT. SW WINDS PREVAIL DURING THE DAY ON WEDNESDAY AT 5-10 KT.
MODELS ARE STARTING TO INDICATE A POTENTIAL WIND SWITCH AROUND 00-
01Z WEDNESDAY TO N.
62
MARINE
STRONGER SOUTH WINDS CONTINUE THROUGH THIS EVENING AS
A WEATHER SYSTEM MOVES ACROSS THE WATERS. GALE FORCE WIND GUSTS
ARE EXPECTED AT TIMES FOR THE COASTAL WATERS, AS WELL AS PUGET
SOUND AND ADMIRALTY INLET THROUGH THIS EVENING. SCA WINDS ARE
EXPECTED FOR OTHER WATERS INTO THE EVENING. ONSHORE FLOW
INCREASES THIS EVENING INTO TONIGHT WITH A STRONG WESTERLY PUSH
THROUGH THE STRAIT OF JUAN DE FUCA. GALE WARNINGS HAVE BEEN
ISSUED FOR THE CENTRAL AND EASTERN PORTIONS OF THE STRAIT OF
JUAN DE FUCA THIS EVENING INTO TONIGHT, WITH GALE FORCE WEST
WIND GUSTS EXPECTED. WINDS WILL SLOWLY SUBSIDE LATE TONIGHT INTO
WEDNESDAY FOR THE MAJORITY OF WATERS. NORTHWEST WINDS INCREASE
FOR THE OUTER COASTAL WATERS LATE WEDNESDAY BEFORE SUBSIDING
THROUGH FRIDAY. ANOTHER WEATHER SYSTEM WILL APPROACH THE WATERS
OFFSHORE OVER THE WEEKEND, RESULTING IN INCREASED SOUTHERLY
WINDS FOR THE COASTAL WATERS.
SEAS WILL BUILD TO 9 TO 12 FEET THIS EVENING. SEAS WILL REMAIN
AROUND 8 TO 10 FEET WEDNESDAY BEFORE BUILDING TO 10 TO 13 FEET
WEDNESDAY NIGHT. SEAS WILL SUBSIDE THURSDAY THROUGH FRIDAY. JD
HYDROLOGY
NO RIVER FLOODING THE NEXT 7 DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...WINTER STORM WARNING UNTIL 11 PM PDT WEDNESDAY FOR CASCADES OF
PIERCE AND LEWIS COUNTIES-CASCADES OF SNOHOMISH AND
NORTHERN KING COUNTIES-CASCADES OF SOUTHERN KING COUNTY-
CASCADES OF WHATCOM AND SKAGIT COUNTIES.
WINTER WEATHER ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
OLYMPICS.
PZ...SMALL CRAFT ADVISORY UNTIL 2 AM PDT WEDNESDAY FOR GRAYS HARBOR
BAR-NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS-
WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
GALE WARNING UNTIL 2 AM PDT WEDNESDAY FOR CENTRAL U.S. WATERS
STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S. WATERS STRAIT
OF JUAN DE FUCA.
GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR ADMIRALTY INLET-
PUGET SOUND AND HOOD CANAL.
SMALL CRAFT ADVISORY UNTIL 5 AM 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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