936
FXUS66 KSEW 241209
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
409 AM PST WED DEC 24 2025
SYNOPSIS
A LOW PRESSURE SYSTEM IS EXPECTED TO MOVE UP ALONG THE COAST INTO
WESTERN WASHINGTON TODAY, BRINGING WIDESPREAD RAIN AND THE POTENTIAL
FOR STRONG WINDS TO THE REGION. ADDITIONAL LIGHT PRECIPITATION
EXPECTED THURSDAY AND FRIDAY. AN UPPER LEVEL RIDGE IS FAVORED TO
BUILD OVER WESTERN WASHINGTON THIS WEEKEND INTO EARLY NEXT WEEK,
BRINGING DRIER CONDITIONS.
SHORT TERM /TODAY THROUGH FRIDAY/
A LOW PRESSURE SYSTEM WILL MOVE UP THE COAST TODAY FROM THE SOUTH.
THIS SYSTEM WILL BRING WIDESPREAD RAIN AND THE POTENTIAL FOR STRONG
WINDS. WINDS WILL START OUT FROM THE EAST THIS MORNING, DOWNSLOPING
THROUGH THE CASCADES AND CHANNELING THROUGH THE CASCADE GAPS WITH
GUSTS TO 45 MPH EXPECTED ALONG THE FOOTHILLS, FOR WHICH A WIND
ADVISORY HAS BEEN ISSUED. AS THE LOW PRESSURE SYSTEM LIFTS
NORTHWARDS, THE WIND DIRECTION WILL ABRUPTLY SHIFT SOUTHWARDS AND
BRING STRONGER WINDS. THERE IS STILL SOME UNCERTAINTY REGARDING THE
WIND FORECAST THIS AFTERNOON. PLEASE CHECK THE WIND SECTION BELOW:
WIND: MODELS CONTINUE TO HAVE SOME DIFFERENCES IN THE EXACT PATH THE
LOW PRESSURE SYSTEM WILL TAKE AND THE MAGNITUDE OF THE WINDS.
HOWEVER, MANY HIGH-RESOLUTION MODELS HAVE RECENTLY BEEN TRENDING
WITH MEAN WIND GUSTS OF 45-50 MPH ALONG PUGET SOUND, WITH A FEW OF
THE HIGHER END SOLUTIONS TRENDING AS HIGH AS 60-65 MPH. IN ADDITION,
THERE IS SOME UNCERTAINTY WHEN PEAK WINDS WILL OCCUR BETWEEN MODELS,
HOWEVER THE GENERAL TIME FRAME IS BETWEEN 12 PM AND 7 PM. WINDS WILL
SUBSIDE IN THE LATE EVENING HOURS.
RAIN TOTALS WITH THIS SYSTEM WILL BE ON THE LIGHT SIDE, WITH SNOW
LEVELS HOVERING AROUND 6000-6500 FT. RAINFALL AMOUNTS FOR THE
LOWLANDS WILL RANGE BETWEEN 0.25-0.35 INCHES, FOR THE COAST VALUES
WILL RANGE BETWEEN 0.45-0.75 INCHES, AND AROUND AN INCH IN THE
MOUNTAINS. ADDITIONAL LIGHT PRECIPITATION EXPECTED THURSDAY AND
FRIDAY.
29
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
LONG-RANGE ENSEMBLES CONTINUE TO FAVOR AN UPPER LEVEL RIDGE TO
SETTLE OVER WESTERN WASHINGTON, WHICH WOULD BRING DRIER CONDITIONS
TO THE REGION. DETERMINISTIC MODELS DO HINT AT AN ATMOSPHERIC RIVER
POTENTIALLY HEADING TOWARDS THE PACIFIC NORTHWEST EARLY NEXT WEEK.
HOWEVER, THE PATH OF THE ATMOSPHERIC RIVER IS CURRENTLY FAVORED TO
STAY TO THE NORTH OF THE REGION AND IMPACT BRITISH COLUMBIA AT THIS
TIME.
29
AVIATION
CURRENTLY VFR AT THE TERMINALS EARLY THIS MORNING, HOWEVER EXPECTING
WIDESPREAD MVFR CEILINGS BY 15Z-18Z. GUIDANCE IS HINTING AT IFR
CONDITIONS, WITH PROBABILITIES AT 20-35% FOR PWT AND CLM. LIFR
CEILINGS ALSO POSSIBLE ALONG THE SOUTHERN INTERIOR (OLM), WITH
PROBABILITIES AT 25-35%. NE WINDS WILL INCREASE THIS MORNING AFTER
12Z, WITH SUSTAINED SPEEDS OF 10-15 KT AND GUSTING TO 25-30 KT. WIND
DIRECTION WILL SHARPLY TURN SOUTHERLY THIS AFTERNOON, AFTER 18Z-20Z.
THESE SOUTHERLY WINDS DURING THE EVENING HOURS WILL BE STRONGER,
WITH SUSTAINED SPEEDS OF 20-30 KT AND GUSTS 35-45 KT LIKELY. THERE
IS A 40-60% CHANCE OF EXCEEDING 50 KT GUSTS. WINDS WILL GRADUALLY
SUBSIDE IN THE EVENING HOURS. PEAK WIND GUSTS EXPECTED BETWEEN 20Z-
02Z.
KSEA...VFR CONDITIONS AT THE TERMINAL EXPECTED TO DETERIORATE TO
MVFR AS EARLY AS 15Z, WITH HIGHER CONFIDENCE BY 21Z. MAY SEE SOME
BRIEF IMPROVEMENT TO VFR BETWEEN 02Z-06Z, HOWEVER CONFIDENCE IS LOW
AND KEPT MVFR CONDITIONS PERSISTING LONGER INTO THE EARLY HOURS OF
THURSDAY. GUSTY NE WINDS 10-15 KT GUSTING TO 30 KT THIS MORNING WILL
RAPIDLY SHIFT SOUTHERLY THIS AFTERNOON AFTER 18Z/19Z. THESE
SOUTHERLIES WILL BE STRONGER WITH SUSTAINED WINDS OF 20-30 KT AND
GUSTS TO 45 KT. GUSTS MAY EXCEED 50 KT, WITH CURRENT PROBABILITIES
AROUND 40%. WINDS WILL GRADUALLY SUBSIDE INTO THE LATE EVENING HOURS
AND SHIFT NE AGAIN INTO THE OVERNIGHT HOURS.
29
MARINE
A RAPIDLY MOVING SURFACE LOW IN THE OREGON COASTAL WATERS
WILL MOVE NORTH INTO THE WASHINGTON COASTAL WATERS THIS MORNING.
THE LOW WILL CONTINUE TO MOVE NORTH AND WEAKEN LATER THIS
AFTERNOON INTO THIS EVENING. A BROAD SURFACE TROUGH WELL TO THE
SOUTH OF THE AREA AND HIGH PRESSURE OVER THE INTERIOR OF BRITISH
COLUMBIA WILL LEAD TO A PERIOD OF NORTHERLY FLOW THURSDAY INTO
FRIDAY. SURFACE HIGH PRESSURE WILL BUILD ACROSS THE WATERS THIS
WEEKEND FOR A QUIETER PERIOD.
GALE FORCE WINDS DEVELOPING OVER ALL THE WATERS WITH THE
EXCEPTION OF THE CENTRAL STRAIT OF JUAN DE FUCA LATER THIS
MORNING INTO THIS AFTERNOON. THE WINDS WILL EASE
QUICKLY FROM SOUTH TO NORTH THIS EVENING WITH SMALL CRAFT
ADVISORIES UP FOR MOST OF THE WATERS JUST IN THE EVENING HOURS.
POSSIBLE SMALL CRAFT ADVISORY WINDS OVER THE COASTAL WATERS
LATER THURSDAY INTO FRIDAY. WINDS EASING OVER THE WEEKEND BUT
WITH THE LIGHTER WINDS COMES A THREAT OF THICK FOG.
SEAS BUILDING TO NEAR 10 FEET FRIDAY BEFORE SUBSIDING FOR THE
WEEKEND. FELTON
HYDROLOGY
RIVERS ACROSS WESTERN WASHINGTON CONTINUE TO TREND
DOWNWARD. RAINFALL THROUGH FRIDAY IS NOT EXPECTED TO CAUSE ANY
ADDITIONAL RISES TO AREA RIVERS. WITH THE LOWER RAIN RATES AND A
POSSIBLE DRY SPELL COMING UP THE THREAT OF LANDSLIDES HAS
DECREASED ACROSS WESTERN WASHINGTON. FELTON
SEW WATCHES/WARNINGS/ADVISORIES
WA...COASTAL FLOOD ADVISORY UNTIL NOON PST TODAY FOR CITY OF
SEATTLE-DOWNTOWN EVERETT / MARYSVILLE AREA-ISLAND COUNTY-
LOWLANDS OF PIERCE AND SOUTHERN KING COUNTIES-LOWLANDS OF
WESTERN SKAGIT AND NORTHWESTERN SNOHOMISH COUNTIES-
LOWLANDS OF WESTERN WHATCOM COUNTY-SAN JUAN COUNTY-
SHORELINE / LYNNWOOD / SOUTH EVERETT AREA.
HIGH WIND WARNING FROM 1 PM THIS AFTERNOON TO 7 PM PST THIS
EVENING FOR DOWNTOWN EVERETT / MARYSVILLE AREA-ISLAND
COUNTY-LOWLANDS OF WESTERN SKAGIT AND NORTHWESTERN
SNOHOMISH COUNTIES-LOWLANDS OF WESTERN WHATCOM COUNTY-
PORT TOWNSEND AREA-SAN JUAN COUNTY.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR FOOTHILLS AND
VALLEYS OF CENTRAL KING COUNTY-FOOTHILLS AND VALLEYS OF
PIERCE AND SOUTHERN KING COUNTIES-FOOTHILLS AND VALLEYS
OF SNOHOMISH AND NORTHERN KING COUNTIES-FOOTHILLS AND
VALLEYS OF THURSTON AND LEWIS COUNTIES-FOOTHILLS AND
VALLEYS OF THE NORTH CASCADES.
HIGH WIND WARNING FROM 10 AM THIS MORNING TO 7 PM PST THIS
EVENING FOR CITY OF SEATTLE-EASTERN KITSAP COUNTY-
EASTSIDE-LOWLANDS OF LEWIS AND SOUTHERN THURSTON COUNTIES-
LOWLANDS OF PIERCE AND SOUTHERN KING COUNTIES-MIDDLE
CHEHALIS RIVER VALLEY-NORTHERN HOOD CANAL-OLYMPIA AND
SOUTHERN PUGET SOUND-SHORELINE / LYNNWOOD / SOUTH EVERETT
AREA-SOUTHERN HOOD CANAL-WILLAPA AND BLACK HILLS.
PZ...GALE WARNING UNTIL 6 PM PST THIS EVENING 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.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT PST
TONIGHT 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.
SMALL CRAFT ADVISORY UNTIL 1 AM PST THURSDAY FOR CENTRAL U.S.
WATERS STRAIT OF JUAN DE FUCA.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 10 PM PST THIS
EVENING FOR ADMIRALTY INLET-EAST ENTRANCE U.S. WATERS
STRAIT OF JUAN DE FUCA-PUGET SOUND AND HOOD CANAL.
GALE WARNING FROM 1 PM THIS AFTERNOON TO MIDNIGHT PST TONIGHT
FOR NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.
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