569
FXUS66 KSEW 192208
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
308 PM PDT SUN OCT 19 2025
SYNOPSIS
UNSETTLED AND COOL CONDITIONS WILL CONTINUE OVER
REGION THIS AFTERNOON. UPPER LEVEL RIDGING LOOKS TO BUILD TONIGHT
THROUGH TUESDAY WITH DRYING CONDITIONS OVER THE AREA. A FRONTAL
SYSTEM LOOKS TO ARRIVE LATE WEDNESDAY, WITH ANOTHER WET AND
POTENTIALLY STRONGER SYSTEM ARRIVING LATER IN THE WEEK THROUGH THE
WEEKEND WHICH COULD POTENTIALLY BRING MODERATE TO HEAVY RAIN AT
TIMES, BREEZY WINDS, AND MOUNTAIN SNOW.
SHORT TERM /TONIGHT THROUGH WEDNESDAY/
RECENT RADAR IMAGERY
SHOWS POST-FRONTAL SHOWERS MOVING THROUGH MOST OF THE REGION, WITH
SOME SHOWERS HAVING SOME CONVECTIVE ACTIVITY WITH THEM. THERE
CONTINUES TO REMAIN A CHANCE (20-25%) OF AN ISOLATED THUNDERSTORM
OR TWO THIS AFTERNOON, BUT THE THREAT LARGELY DIMINISHES THIS
EVENING. A CONVERGENCE ZONE WILL PERSIST THROUGHOUT THE EVENING
BUT WILL MAINLY STAY OVER SNOHOMISH AND KING COUNTY, WITH LIKELY
ADDITIONAL SHOWERS IN THOSE AREAS. WITH SNOW LEVELS GENERALLY
AROUND 4500 TO 5000 FEET, A WINTER WEATHER ADVISORY WILL REMAIN
FOR THE NORTH CASCADES UNTIL LATE TONIGHT AS SHOWERS WILL LIKELY
LINGER. AN UPPER LEVEL RIDGE BEGINS TO BUILD OVERNIGHT INTO
MONDAY, WITH CONDITIONS STARTING TO DRY OUT OVER THE AREA. HIGH
TEMPERATURES ON MONDAY WILL TREND IN THE UPPER 50S, WITH SOME
LOCATIONS POTENTIALLY REACHING THE LOW 60S.
CONDITIONS WILL CONTINUE TO BE DRY INTO TUESDAY WITH SUNSHINE AT
TIMES, MAKING TUESDAY LIKELY THE WARMEST DAY IN THE WEEK, WITH
TEMPERATURES IN THE LOWER 60S FOR MUCH OF THE AREA. ENSEMBLES
HAVE BEEN IN AGREEMENT WITH A A WEAK SYSTEM MOVING IN WEDNESDAY
WITH SOME LIGHT SHOWERS SPREADING ACROSS THE REGION. HIGH
TEMPERATURES WILL STAY IN THE MID TO UPPER 50S.
LONG TERM /THURSDAY THROUGH SUNDAY/
THE PATTERN BECOMES MORE
ACTIVE IN THE LONG TERM AS A STRONGER SYSTEM MOVES OVER WESTERN
WASHINGTON ON THURSDAY INTO FRIDAY. THERE ARE STILL SOME STRENGTH
INCONSISTENCIES BUT IT DOES LOOK LIKE THIS SYSTEM WILL BRING
MODERATE TO HEAVY RAIN AT TIMES, WITH WIDESPREAD RAIN ACROSS THE
REGION. MOST OF THE PRECIPITATION WILL LIKELY BE OROGRAPHICALLY
LIFTED AND FALL IN THE OLYMPICS AND THE CASCADES. ADDITIONALLY, WINDS
LOOK TO BECOME BREEZY OVER MUCH OF THE AREA, ALONG WITH MOUNTAIN
SNOW. RAIN LOOKS TO CONTINUE THROUGH MUCH OF THE WEEKEND AS A
COOL UPPER LEVEL TROUGH REMAINS PARKED OVER THE PACIFIC NORTHWEST,
KEEPING THE PATTERN UNSETTLED AND RAINY.
MAZURKIEWICZ
AVIATION
WINDS HAVE REMAINED GUSTY ACROSS MOST TO ALL WESTERN
WASHINGTON TERMINALS THIS AFTERNOON. AS SUCH, IN THE POST FRONTAL
ENVIRONMENT, THE CESSATION OF THE GUSTS HAVE LARGELY BEEN PUSHED
BACK IN THE TAFS TO AFTER 03Z RATHER THAN COMING TO AN END AROUND
00Z. CEILINGS ARE VFR TO MVFR, AND WILL CONTINUE THAT WAY THROUGHOUT
MUCH OF THE EVENING, WITH SOME REDUCTIONS BACK TO MVFR OVERNIGHT.
CONVERGENCE ZONE ACTIVITY IS SHAPING UP ALONG THE KING AND SNOHOMISH
COUNTY LINE, WITH ADDITIONAL BANDS NORTH IN SKAGIT COUNTY. WHILE THE
ATMOSPHERE REMAINS SOMEWHAT UNSTABLE, IT HASN'T BEEN ENOUGH SO FAR
THIS AFTERNOON TO SPUR ON ANY THUNDERSTORMS. WHILE IT CANNOT BE
FULLY RULED OUT BETWEEN NOW AND SUNSET, THE CHANCES ARE STILL SLIM
OVERALL, AND NOT WORTHY OF INCLUDING IN ANY TAF AT THIS TIME.
OVERNIGHT, EXPECT WINDS TO EASE AND REMAIN LARGELY SOUTHERLY FOR
AREAS OF CENTRAL AND SOUTHERN PUGET SOUND, WITH GUSTY WESTERLIES
THROUGH THE STRAIT OF JUAN DE FUCA. SINCE THE GROUND AND LOWER
ATMOSPHERE ARE SUFFICIENTLY MOISTENED, AREAS OF LOW STRATUS AND
POCKETS OF FOG ARE POSSIBLE OVERNIGHT. THIS IS INDICATED IN MANY OF
THE TAFS BEGINNING EARLY MONDAY MORNING.
KSEA...CEILINGS ARE STILL OSCILLATING BETWEEN VFR AND MVFR THIS
AFTERNOON, WITH SOUTHWESTERLY GUSTS OF 20-30 KTS LIKELY TO PERSIST
THROUGH 03Z. THEREAFTER, WIND SPEEDS ARE EXPECTED TO TAPER AND
REMAIN SOUTHERLY INTO THE OVERNIGHT PERIOD. FROM THIS POINT FORWARD
INTO THE OVERNIGHT HOURS, EXPECT ISOLATED SHOWERS. CONFIDENCE IS LOW
THAT THERE WOULD BE ANY SIGNIFICANT SOUTHERLY DRIFT OF THE
CONVERGENCE ZONE IN A WAY THAT WOULD IMPACT SEA. CHANCES FOR
THUNDERSTORMS ARE VERY LIMITED BETWEEN NOW AND SUNSET. A REDUCTION
BACK TO MVFR CIGS EARLY MONDAY MORNING IS EXPECTED DUE TO A
MOISTENED LOWER ATMOSPHERE. SOME CLOUDS AND LOW STRATUS COULD LINGER
AT THE TERMINAL FOR PORTIONS OF MONDAY MORNING.
21
MARINE
WITH INCREASING ONSHORE FLOW ACROSS THE WATERS BEHIND THE
PASSING FRONT THAT IS NOW WELL EAST, CONTINUING TO SEE STRONG WEST
WINDS DEVELOP THROUGH THE STRAIT OF JUAN DE FUCA AS WELL AS THE
COASTAL WATERS. EXPECT THE GENERAL WINDS THROUGH PUGET SOUND AND
OVER THE COASTAL WATERS TO EASE OVER THE NEXT FEW HOURS, BUT
PERSISTENT WESTERLIES IN THE STRAIT WILL LINGER INTO TONIGHT. AS A
RESULT, EXTENDED THE GALE WARNING FOR THE CENTRAL STRAIT THROUGH 10
PM. MEANWHILE, SEAS ARE PEAKING OVER THE COASTAL WATERS AT 18-23 FT,
AND EXPECT A TREND OF SEAS GRADUALLY SUBSIDING INTO MONDAY.
CONDITIONS WILL REMAIN QUITE ROUGH ON THE GRAYS HARBOR BAR
OVERNIGHT, ESPECIALLY AROUND THE EBBS THIS EVENING AND EARLY MONDAY
MORNING.
HIGH PRESSURE BUILDS OVER THE WATERS WITH WINDS MONDAY AND TUESDAY
NOT NEARLY AS STRONG. HOWEVER, WILL NEED TO WATCH FOR BUILDING WAVES
AGAIN TUESDAY AS A WEAK SYSTEM PASSES TO THE NORTH. WHILE CURRENT
NWPS OUTPUT SUGGESTS WAVES AROUND 15-17 FEET, THERE'S SOME SIGNAL
FOR SOME ENHANCEMENT AS WAVES GENERATED NEAR THE GULF OF ALASKA AND
OFF NORTHERN VANCOUVER ISLAND MAKE THEIR WAY INTO THE LOCAL WATERS.
MORE SIGNIFICANTLY, A STRONGER FRONTAL SYSTEM MOVING TOWARD THE
LOCAL AREA THURSDAY INTO FRIDAY MAY BRING ANOTHER ROUND OF 20+ FT
SEAS, WITH THE ECMWF ENSEMBLE GUIDANCE SUGGESTING NON-TRIVIAL
CHANCES OF SEAS EVEN APPROACHING 25 FT OVER THE COASTAL WATER. WHILE
THERE'S LOW CERTAINTY WITH RESPECT TO THE PRECISE TRACK OF THAT
STRONGER SYSTEM, IT'S WORTH NOTING THAT EVEN A SYSTEM THAT DOESN'T
TRACK IMMEDIATELY THROUGH THE LOCAL AREA CAN STILL SPREAD LARGE
WAVES ACROSS THE NORTHEASTERN PACIFIC AND INTO THE COASTAL WATERS.
EVEN WITH THE CURRENT GUIDANCE, THERE'S A HIGH POTENTIAL OF AT LEAST
GALE GUSTS ACROSS MUCH OF THE WATERS (>75% CHANCE) AND AT LEAST A 40-
50% CHANCE OF LOCALIZED STORM FORCE GUSTS THURSDAY NIGHT AND FRIDAY.
CULLEN
HYDROLOGY
SHOWER ACTIVITY OVER THE NEXT FEW DAYS WILL NOT
RESULT IN ANY HYDROLOGICALLY SIGNIFICANT PRECIPITATION. SYSTEM
ARRIVING ON WEDNESDAY WILL BRING ANOTHER ROUND OF RAIN TO THE
AREA WITH UP TO AN INCH IN THE MOUNTAINS. A WETTER SYSTEM WILL
ARRIVE LATER THURSDAY INTO FRIDAY. THIS SYSTEM COULD BE TAPPING
INTO SOME SUB TROPICAL MOISTURE BRINGING UP THE POSSIBILITY OF
HYDROLOGICALLY SIGNIFICANT RAINFALL OVER THE OLYMPICS THURSDAY
NIGHT INTO FRIDAY. CURRENT FORECAST HAS 2 TO 4 INCHES OF
PRECIPITATION OVER THE OLYMPICS THURSDAY NIGHT INTO FRIDAY. SNOW
LEVELS NOT EXCESSIVELY HIGH, 6000 TO 7000 FEET, KEEPING SOME OF
THE WATER IN THE OLYMPICS IN THE FORM OF SNOW INSTEAD OF RUNOFF.
THERE IS STILL PLENTY OF TIME FOR THIS SOLUTION TO CHANGE. THE
FIRST SKOKOMISH RIVER FLOOD OF THE SEASON IS STILL A POSSIBILITY.
FELTON
SEW WATCHES/WARNINGS/ADVISORIES
WA...WINTER WEATHER ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
CASCADES OF WHATCOM AND SKAGIT COUNTIES.
PZ...SMALL CRAFT ADVISORY UNTIL 6 PM PDT MONDAY 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-GRAYS HARBOR BAR.
SMALL CRAFT ADVISORY UNTIL 6 AM PDT MONDAY FOR 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 6 PM PDT THIS EVENING FOR CENTRAL U.S. WATERS
STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM PDT MONDAY
FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 6 PM PDT THIS EVENING FOR PUGET SOUND
AND HOOD CANAL.
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