932
FXUS66 KSEW 232231
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
231 PM PST TUE DEC 23 2025
SYNOPSIS
QUIESCENT WEATHER IS EXPECTED THIS AFTERNOON, WITH MORE ACTIVITY
EXPECTED TOMORROW. A DEEPENING LOW PRESSURE SYSTEM WILL BE
MOVING UP ALONG THE COAST INTO WESTERN WASHINGTON TOMORROW,
FAVORING STRONG WIND POTENTIAL IN PUGET SOUND AND ALONG THE
COAST, IN ADDITION TO SOME RAINFALL. UNSETTLED WEATHER IS
EXPECTED AGAIN THIS WEEKEND AND INTO EARLY NEXT WEEK.
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/
THE PRIMARY WEATHER FEATURE TO WATCH IN THE SHORT TERM WILL BE
THE LOW PRESSURE SYSTEM MOVING UP FROM THE SOUTH TOMORROW. AS IT
MOVES NORTH AND STRENGTHENS, WIND GUSTS HAVE INCREASED IN THE
FORECAST THOUGH UNCERTAINTY STILL REMAINS. FOR MORE ON THAT, SEE
THE WIND SECTION OF THIS DISCUSSION HERE:
WIND: A COMPACT LOW PRESSURE SYSTEM DEVELOPING ALONG THE NORTHERN
CALIFORNIA COAST THIS EVENING WILL LIFT NORTHWARD TOWARD THE PACIFIC
NORTHWEST ON WEDNESDAY. MODELS CONTINUE TO STRUGGLE WITH THE PATH
AND SUBSEQUENT STRENGTH OF THE SURFACE LOW AS IT APPROACHES WESTERN
WASHINGTON MIDDAY WEDNESDAY. MORNING RUNS OF THE HREF AND REFS
CONTINUED TO SHOW MEAN GUSTS OF 45-50 MPH THROUGH PUGET SOUND AS
WELL AS COASTAL AREAS BY EARLY TO MID AFTERNOON WEDNESDAY WITH 90TH
PERCENTILE DATA SHOWING GUSTS IN THE REALM OF 60 MPH. AS WITH MANY
HIGH WIND PRODUCING STORM SYSTEMS (I.E. LAST WEEK), DEFERENCE IS
ALSO GIVEN TO THE RATE OF CHANGE OF SURFACE PRESSURE AND
TOPOGRAPHICALLY DRIVEN CONTRIBUTIONS. AS OF THIS MORNING,
ISALLOBARIC PLOTS FROM BOTH THE GFS AND NAM WERE STILL SHOWING 8 TO
12 MILLIBARS OF PRESSURE RISE IN JUST 3 HOURS THROUGH A SWATH OF THE
COAST AND PUGET SOUND ON WEDNESDAY AFTERNOON. FUNNELING THAT THROUGH
A NORTH/SOUTH ORIENTED CHANNEL LIKE PUGET SOUND CAN ACT TO ENHANCE
THE WIND...ESPECIALLY WHEN 850 MILLIBAR WINDS ARE ROUGHLY FROM THE
SAME DIRECTION AT 60+ KNOTS. GIVEN THE ONGOING UNCERTAINTY, A HIGH
WIND WATCH HAS BEEN ISSUED FOR MUCH OF THE LOWLANDS AND WILL LET
FOLLOWING SHIFTS DECIDE ON WARNINGS VERSUS ADVISORIES. 27
IN ADDITION TO THE WIND, THERE WILL ALSO BE SOME RAIN WITH THIS
SYSTEM, BUT AMOUNTS AREN'T LOOKING PARTICULARLY IMPRESSIVE. A
FEW TENTHS OF AN INCH UP TO A QUARTER INCH THROUGHOUT PUGET
SOUND AND AROUND AN INCH IN THE NORTH CASCADES AND PORTIONS OF
THE OLYMPICS. IN THE CONTEXT OF THE LAST FEW WEEKS, CERTAINLY
NOT IMPACTFUL RAIN AMOUNTS. ADDITIONAL, LIGHT RAIN AMOUNTS ARE
EXPECTED THURSDAY, WITH CALMER WEATHER EXPECTED OVER THE
WEEKEND.
21
LONG TERM /FRIDAY THROUGH TUESDAY/
UPPER LEVEL RIDGING APPEARS TO BE THE FAVORED FORECAST SOLUTION
LATE IN THE WEEK INTO THE WEEKEND, WHICH WOULD BE A WELCOME
BREAK FROM THE LAST FEW WEEKS OF INTENSE ACTIVITY. THIS REPRIEVE
WILL BE RELATIVELY SHORT LIVED AS UNSETTLED WEATHER IS FAVORED
IN THE WEEK TWO TIMEFRAME FROM THE CPC. THERE IS POTENTIAL FOR
MORE ATMOSPHERIC RIVER ACTIVITY IN THIS PERIOD, BUT THERE IS NOT
SOLID CONFIDENCE ON THIS AS OF NOW.
21
AVIATION
VFR CIGS PREVAIL FOR ALL TERMINALS THIS AFTERNOON WITH LIGHT
ENE WINDS. RAIN WILL BE REINTRODUCED TO MOST TERMINALS LATE
TONIGHT AROUND 09Z. LOCATIONS THAT COULD SEE REDUCTIONS
OVERNIGHT TO MVFR AND/OR IFR INCLUDE OLM AND PWT FOR STRATUS AND
LOW CIGS. ESE WINDS WILL INCREASE TOMORROW MORNING GENERALLY
AROUND 12Z, BUT THERE IS A SHARP INCREASE AND DIRECTION CHANGE
TO SOUTHERLY IN THE EARLY AFTERNOON THAT WILL AFFECT ALL
TERMINALS. HIGH END GUSTS IN PUGET SOUND COULD NEAR 45-50 KTS
BETWEEN 20Z-01Z.
KSEA...VFR AND LIGHT WINDS PRESENTLY AT THE TERMINAL. THESE
CONDITIONS ARE LIKELY TO LINGER THROUGHOUT THE EVENING, WITH AN
EXPECTED INCREASE IN THE ESE WINDS TO 8-10 KTS BEGINNING AFTER
06Z. RAIN CHANCES RETURN AFTER 09Z AS THE NEXT SYSTEM
APPROACHES. EXPECT ESE GUSTS TO 20-25 KTS TO BEGIN AFTER 14Z,
AND A RAPID SHIFT AND INCREASE TO S WINDS AFTER 19Z. CONFIDENCE
HAS GROWN IN GUSTS REACHING 45-50 KTS AT THE TERMINAL TOMORROW
AFTERNOON.
21
MARINE
A STRONG SURFACE LOW PRESSURE SYSTEM IS EXPECTED TO LIFT NORTHWARD
ACROSS THE COASTAL WATERS OR OLYMPIC PENINSULA ON WEDNESDAY. THIS IS
EXPECTED TO PRODUCE GALES ACROSS NEARLY ALL AREA WATERS. A BROAD
SURFACE TROUGH WILL REMAIN TO THE SOUTHWEST OF THE AREA AND HIGH
PRESSURE OVER INTERIOR BRITISH COLUMBIA FOR A PERIOD OF NORTHERLY
FLOW ON THURSDAY INTO FRIDAY. SURFACE HIGH PRESSURE WILL BUILD OVER
THE WATERS THIS WEEKEND FOR A QUIETER PERIOD OF WEATHER.
SEAS WILL SUBSIDE BELOW 10 FEET TONIGHT INTO WEDNESDAY. SEAS MAY
BRIEFLY APPROACH 10 FEET WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT,
BUT GENERALLY ARE EXPECTED TO REMAIN BELOW 10 FEET INTO THE END OF
THE WEEK.
27
HYDROLOGY
RIVERS ACROSS WESTERN WASHINGTON CONTINUE TO TREND DOWNWARD AS
PRECIPITATION ACROSS THE REGION LIGHTENS UP. THE SKOKOMISH
RIVER IS THE ONLY RIVER TO REMAIN IN FLOOD STAGE UNTIL
WEDNESDAY.
ADDITIONAL RAINFALL THROUGHOUT THE WEEK IS NOT EXPECTED TO CAUSE
ANY ADDITIONAL RISES TO AREA RIVERS, AND FLOODING OUTSIDE OF THE
SKOKOMISH RIVER IN MASON COUNTY IS NOT EXPECTED OVER THE NEXT 7
DAYS.
ADDITIONALLY, THE THREAT OF LANDSLIDES HAS DECREASED ACROSS
WESTERN WASHINGTON.
JD/15
SEW WATCHES/WARNINGS/ADVISORIES
WA...HIGH WIND WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR CITY OF SEATTLE-DOWNTOWN EVERETT / MARYSVILLE
AREA-EASTERN KITSAP COUNTY-EASTSIDE-FOOTHILLS AND VALLEYS
OF PIERCE AND SOUTHERN KING COUNTIES-FOOTHILLS AND
VALLEYS OF THE NORTH CASCADES-GRAYS HARBOR COUNTY COAST-
ISLAND COUNTY-LOWER CHEHALIS RIVER VALLEY-LOWLANDS OF
LEWIS AND SOUTHERN THURSTON COUNTIES-LOWLANDS OF PIERCE
AND SOUTHERN KING COUNTIES-LOWLANDS OF WESTERN SKAGIT AND
NORTHWESTERN SNOHOMISH COUNTIES-LOWLANDS OF WESTERN
WHATCOM COUNTY-MIDDLE CHEHALIS RIVER VALLEY-NORTHERN HOOD
CANAL-NORTHERN WASHINGTON COAST-OLYMPIA AND SOUTHERN
PUGET SOUND-PORT TOWNSEND AREA-SAN JUAN COUNTY-SHORELINE
/ LYNNWOOD / SOUTH EVERETT AREA-WILLAPA AND BLACK HILLS.
PZ...GALE WARNING FROM 1 AM WEDNESDAY TO 1 AM PST 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-WEST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY FROM 1 AM WEDNESDAY TO 1 AM PST THURSDAY
FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA.
GALE WARNING FROM 9 AM WEDNESDAY TO MIDNIGHT PST WEDNESDAY
NIGHT FOR ADMIRALTY INLET-EAST ENTRANCE U.S. WATERS
STRAIT OF JUAN DE FUCA-NORTHERN INLAND WATERS INCLUDING
THE SAN JUAN ISLANDS.
GALE WARNING FROM 9 AM TO 10 PM PST WEDNESDAY FOR PUGET SOUND
AND HOOD CANAL.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page