646
FXUS66 KSEW 131041
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
341 AM PDT THU MAR 13 2025
SYNOPSIS
SHOWERS WILL CONTINUE THROUGHOUT THE DAY WITH A CHANCE
FOR ISOLATED THUNDERSTORMS IN THE AFTERNOON. UPPER LEVEL TROUGHING
WILL CONTINUE TO BRING ADDITIONAL SYSTEMS THROUGH FRIDAY AND INTO
THE WEEKEND WHICH HAVE THE POTENTIAL TO BRING MORE ROUNDS OF
HEAVIER RAINFALL, MORE MOUNTAIN SNOW, AND BREEZY CONDITIONS.
SHORT TERM /TODAY THROUGH SATURDAY/
RADAR IMAGERY THIS MORNING
SHOWS SCATTERED SHOWERS ACROSS THE INTERIOR, WITH SNOW IN THE
MOUNTAINS. SNOW LEVELS THIS MORNING GENERALLY IN THE 1000 TO 1500
FEET, WITH THE CASCADES AND PASSES RECEIVING ACCUMULATING SNOW
(POSSIBLY HEAVY AT TIMES) EARLY THIS MORNING AS A BATCH OF HEAVIER
MOISTURE PERSISTS OVER THE MOUNTAINS. A WINTER WEATHER ADVISORY
CONTINUES UNTIL NOON. SCATTERED SHOWERS WILL CONTINUE THROUGHOUT
THE DAY OVER THE INTERIOR AS AN UPPER TROUGH AXIS SHIFTS
OVERHEAD. THE AIR MASS WILL BE UNSTABLE THIS AFTERNOON WHICH MAY
LEAD TO THE CHANCE OF AN ISOLATED THUNDERSTORM OR TWO, ESPECIALLY
THIS EVENING. THE GREATEST AREAS OF INSTABILITY VALUES LOOK TO BE
OVER SW WASHINGTON, BUT REGARDLESS, A FEW ISOLATED LIGHTNING
STRIKES CAN BE POSSIBLE OVER THE INTERIOR THIS AFTERNOON.
COOLER AND WETTER WEATHER IS ON TRACK FOR FRIDAY AS ANOTHER
SHORTWAVE SYSTEM PUSHES THROUGH THE REGION, WITH MOST OF THE
ENERGY ASSOCIATED WITH THIS LOCATED MORE SOUTHWARD. ANOTHER DAY
OF RAIN SHOWERS IS TO BE EXPECTED, WITH SNOWFALL IN THE MOUNTAINS.
SNOW LEVELS LOOK TO RAISE SLIGHTLY TO AROUND 2000 TO 2500 FEET BY
LATE FRIDAY NIGHT.
THE ACTIVE WEATHER PATTERN CONTINUES, WITH A STEADIER STREAM OF
MOISTURE AIMED AT WESTERN WA STARTING FRIDAY NIGHT INTO SATURDAY,
WITH ANOTHER ROUND OF LOWLAND RAIN AND WITH WESTERLY OROGRAPHIC
FLOW, COULD SUPPORT MORE SIGNIFICANT SNOWFALL IN THE MOUNTAINS AS
WELL. COULD ALSO SEE SOME BREEZY WINDS ACROSS THE AREA WITH THE
A SURFACE LOW LOOMING OFFSHORE, MAINLY FOR AREAS NEAR THE
COASTLINE.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
ADDITIONAL SYSTEMS LOOK TO
IMPACT THE AREA CONTINUING THROUGH THE WEEKEND, WITH MORE LOWLAND
RAIN, MOUNTAIN SNOW, AND BREEZY CONDITIONS. SNOW WILL CONTINUE
THROUGH THE WEEKEND WITH SOME LOCATIONS IN THE CASCADES RECEIVING
POTENTIALLY 2 FEET OF FRESH SNOW, WITH SNOW LEVELS GENERALLY
HOVERING AROUND 2000-2500 FEET. HEAVIER PRECIPITATION IN THE
OLYMPICS MAY DRIVE THE SKOKOMISH RIVER IN MASON COUNTY INTO FLOOD
STAGE. CONDITIONS LOOK TO LIGHTEN UP THROUGH MIDWEEK, WITH
ADDITIONAL SHOWERS LIKELY EACH DAY BEFORE A RIDGE ATTEMPT TO SET
UP AT THE END OF THE LONG TERM PERIOD.
MAZURKIEWICZ
AVIATION
MOSTLY MVFR CONDITIONS EARLY THIS MORNING THROUGH THE
REGION WITH STEADY PRECIPITATION EXTENDING THROUGH THE I-5
CORRIDOR/PUGET SOUND REGION EAST INTO THE MOUNTAINS, WITH POCKETS OF
IFR IN THE HEAVIER PRECIPITATION. AS THIS SYSTEM MOVES EASTWARD,
WIDESPREAD SHOWERS WILL LIKELY DEVELOP ACROSS AREA FROM WEST TO
EAST. MEANWHILE, EXPECT NORTHERLY COMPONENT TO THE WIND FOR THE NEXT
FEW HOURS NORTH OF KPWT/KPLU LINE, BEFORE A RETURN OF SOUTHERLY
WINDS THIS AFTERNOON. EXPECT INCREASED GUSTS TO AROUND 20 KT THIS
AFTERNOON FOR THE PUGET SOUND TERMINALS (WESTERLIES THROUGH KCLM
ACROSS WHIDBEY ISLAND). THIS SHOULD YIELD PRIMARILY VFR CEILINGS
THIS AFTERNOON, BUT POCKETS OF LOWER CEILINGS/VISIBILITY IN HEAVIER
SHOWERS. A FEW ISOLATED THUNDERSTORMS CAN'T BE RULED OUT, ESPECIALLY
INTO THE AFTERNOON, BUT CONFIDENCE ISN'T HIGH ENOUGH FOR INCLUSION
IN ANY TAFS AT THIS TIME.
KSEA...MVFR TO LOW VFR CEILINGS EXPECTED IN RAIN THIS MORNING WITH
NORTHERLY WINDS LIKELY SHIFTING TO SOUTHERLY IN 12-13Z RANGE AS THE
FRONTAL BAND APPROACHES. EXPECT A LULL IN SHOWER ACTIVITY THOUGH
CONFIDENCE IN CEILINGS ISN'T TERRIBLY HIGH FOR THE MORNING PUSH WITH
MVFR MOST LIKELY, BUT SOME INDICATIONS OF SHORT IMPROVEMENT TOWARD
3000-3500 FT. OTHERWISE, SOUTHERLY WINDS THROUGH THE REMAINDER OF
THE DAY WITH GUSTS TO 20 KT THIS AFTERNOON 18Z ONWARD BEFORE EASING
AFTER 03Z THIS EVENING. SHOWERS INCREASE AGAIN TOWARD 21Z INTO THE
AFTERNOON, WITH THE STRONGEST OF THESE PERHAPS BRINGING THE
POTENTIAL OF A THUNDERSTORM OR TWO (10-15% CHANCE). OTHERWISE,
DECREASING SHOWERS AND LIKELY VFR CEILINGS THURSDAY EVENING.
MARINE
SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE COASTAL
WATERS AND WEST ENTRANCE OF THE STRAIT OF JUAN DE FUCA THIS MORNING
AS SEAS ARE HOLDING IN THE 9 TO 12 FT RANGE. WINDS MAY REMAIN AROUND
20 KT THROUGH THE CENTRAL/EASTERN STRAIT EARLY THIS MORNING THROUGH
THE DAY AND A FEW OCCASIONAL GUSTS AROUND 25 KT CAN'T BE RULED OUT.
OTHERWISE, A BIT OF A LULL THROUGH MUCH OF THE DAY, WITH ANOTHER
ROUND OF GUSTY SOUTHERLY WINDS AGAIN TONIGHT INTO EARLY FRIDAY. AT
THIS POINT, IT'S MOST LIKELY THAT A SHORT BREAK IN SCA CONDITIONS
BETWEEN THE SEAS AND THE NEXT ROUND OF WINDS WILL ALLOW FOR A PERIOD
OF TIME WITHOUT MARINE HEADLINES, BUT THE NEXT APPROACHING FRONTAL
SYSTEM WILL AGAIN BRING INCREASING SOUTHERLIES TO AT LEAST THE
COASTAL WATERS LATE TONIGHT OR EARLY FRIDAY. AS ADDITIONAL
DISTURBANCES CONTINUE TO PUSH THROUGH THE REGION (ONE FRIDAY,
ANOTHER AROUND SUNDAY), EXPECT TO SEE BOTH WINDS AND SEAS INCREASE
AND ADDITIONAL ADVISORIES WILL BE NEEDED. THE LIKELIHOOD OF GALE
GUSTS INTO THE WEEKEND THROUGH EARLY NEXT WEEK PEAK AROUND AROUND
40% OVER THE COASTAL WATERS FRIDAY AND EARLY SUNDAY, BUT CONFIDENCE
ISN'T HIGH ENOUGH OVER THE LOCAL WATERS TO ISSUE A GALE WATCH AT
THIS TIME. HOWEVER, SEAS AROUND 15 FT ARE EXPECTED OVER THE COASTAL
WATERS AT TIMES FRIDAY AND INTO THE WEEKEND, AND LIKELY REMAIN ABOVE
10 FT THROUGH THE EARLY PART OF NEXT WEEK. CULLEN
HYDROLOGY
HEAVY PRECIPITATION IN THE SOUTHERN OLYMPICS THIS
WEEKEND WILL FORCE SHARP RISES ON THE SKOKOMISH RIVER WITH
FLOODING POSSIBLE. A HYDROLOGIC OUTLOOK HAS BEEN ISSUED. RIVER
FLOODING IS NOT EXPECTED ELSEWHERE OVER THE NEXT 7 DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...WINTER WEATHER ADVISORY UNTIL NOON PDT TODAY FOR WEST SLOPES
NORTH CASCADES AND PASSES-WEST SLOPES NORTH CENTRAL
CASCADES AND PASSES-WEST SLOPES SOUTH CENTRAL CASCADES AND
PASSES.
PZ...SMALL CRAFT ADVISORY UNTIL 3 AM PDT EARLY THIS MORNING 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.
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