269
FXUS66 KSEW 141033
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
333 AM PDT SAT MAR 14 2026
SYNOPSIS
SHOWER ACTIVITY WILL GRADUALLY TAPER ACROSS WESTERN
WASHINGTON THROUGHOUT THE DAY TODAY. DRIER CONDITIONS ARE EXPECTED
ON SUNDAY MORNING, BEFORE THE NEXT ROUND OF PRECIPITATION MOVES
INTO THE REGION SUNDAY NIGHT INTO MONDAY. AN ATMOSPHERIC RIVER
WILL BRUSH THE AREA EARLY NEXT WEEK, THEN LOOKS TO SLOWLY SAG
SOUTHWARD. THIS WILL BRING MUCH WARMER TEMPERATURES AND PERIODS
OF WIDESPREAD RAIN TO WESTERN WASHINGTON AT TIMES THROUGHOUT THE
NEXT WEEK.
SHORT TERM /TODAY THROUGH MONDAY/
THE STALLED FRONTAL BOUNDARY THAT WAS OVER THE REGION THE PAST 2
DAYS CONTINUES TO PUSH SOUTHEASTWARD OUT OF THE AREA EARLY THIS
MORNING, BRINGING AN END TO THE WIDESPREAD RAIN AND SNOW ACROSS
WESTERN WASHINGTON. A TROUGH AXIS SWINGING ONSHORE WILL HELP
GENERATE SOME ADDITIONAL SHOWER ACTIVITY ACROSS THE AREA
THROUGH THE MORNING HOURS. LATEST GUIDANCE CONTINUES TO HINT AT
THE DEVELOPMENT OF A CONVERGENCE ZONE ACROSS THE CENTRAL SOUND
THIS MORNING, WHICH MAY BRING A FEW MORE INCHES OF SNOW TO THE
CASCADE PASSES. TEMPERATURES AS OF 09Z ARE GENERALLY TRENDING IN
THE LOW TO MID 30S ACROSS THE MAJORITY OF THE LOWLANDS- AND CAN
EXPECT OUTLYING AREAS AWAY FROM PUGET SOUND TO DROP NEAR THE
FREEZING MARK OVER THE NEXT COUPLE OF HOURS. SNOW OR A RAIN/SNOW
MIX WILL BE POSSIBLE FOR PORTIONS OF THE LOWLANDS IN ANY
HEAVIER SHOWER ACTIVITY THIS MORNING. WHILE MINIMAL
ACCUMULATIONS ARE EXPECTED, THE FOOTHILLS WOULD HAVE THE BEST
CHANCE FOR ANY ADDITIONAL SNOW ACCUMULATIONS. OTHERWISE, EXPECT
THE LINGERING MOISTURE ON AREA ROADWAYS AND COOL OVERNIGHT
TEMPERATURES TO LEAD TO SOME SLIPPERY ROAD CONDITIONS THIS
MORNING. SHOWER ACTIVITY WILL GRADUALLY TAPER THIS AFTERNOON AND
EVENING WITH OVERALL DRIER CONDITIONS EXPECTED AS WEAK UPPER
LEVEL RIDGING STARTS TO NUDGE INTO THE REGION. AFTERNOON HIGH
TEMPERATURES WILL WARM ROUGHLY 10 DEGREES IN COMPARISON TO
FRIDAY AND GENERALLY LOOK TO MAKE IT INTO THE MID TO UPPER 40S.
EXPECT ANOTHER CHILLY START TO THE DAY ON SUNDAY, WITH MORNING
LOWS EXPECTED TO BE IN THE UPPER 20S TO MID 30S ACROSS MUCH OF
THE AREA. A BRIEF DRY BREAK IS EXPECTED ON SUNDAY MORNING,
BEFORE PRECIPITATION STARTS TO MOVE BACK INTO THE REGION AHEAD
OF AN APPROACHING WARM FRONT SUNDAY NIGHT INTO MONDAY. AFTERNOON
HIGHS ON SUNDAY WILL AGAIN BE IN THE 40S FOR MUCH OF THE AREA.
A WARMER AND WETTER PATTERN COMMENCES SUNDAY NIGHT INTO MONDAY
AS AN ATMOSPHERIC RIVER MOVES INTO BRITISH COLUMBIA. SNOW LEVELS
WILL RISE TO 7000-9000 FT ACROSS WESTERN WASHINGTON ON MONDAY
AND WHILE THE BULK OF THE MOISTURE LOOKS TO REMAIN POSITIONED
TO THE NORTH OF THE AREA THROUGH THE DAY, PRECIPITATION DOES
STILL LOOK TO BRUSH THE NORTHERN 2/3RDS OF WESTERN WASHINGTON.
AFTERNOON HIGHS ON MONDAY WILL BE IN THE 50S - WITH A FEW SPOTS
POTENTIALLY EVEN APPROACHING 60 SOUTH OF THE SOUND.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
A WARMER AND WETTER PATTERN LOOKS TO PERSIST THROUGH MUCH OF
THE NEXT WEEK. WHILE UNCERTAINTY STILL REMAINS IN THE EXACT
POSITIONING OF THE ATMOSPHERIC RIVER, LATEST GUIDANCE DOES
INDICATE THE AXIS OF THE MOISTURE SLOWLY SAGGING SOUTHWARD ON
TUESDAY AND BRINGING ADDITIONAL ROUNDS OF RAIN TO THE AREA
THROUGH THURSDAY. THE MAIN CONCERN NEXT WEEK WILL BE POTENTIAL
HYDROLOGICAL IMPACTS FROM HIGHER SNOW LEVELS AND FROM RAIN ON
SNOW IN THE MOUNTAINS. SEE THE HYDROLOGY SECTION BELOW FOR
ADDITIONAL DETAILS ON RIVER FLOODING. TEMPERATURES WILL
CLIMB THROUGHOUT THE WEEK, WITH HIGHS APPROACHING THE UPPER 50S
TO LOW 60S THURSDAY AND FRIDAY.
14
AVIATION
WESTERLY FLOW ALOFT WILL CONTINUE BEFORE FLOW
TRANSITIONS MORE NW THIS AFTERNOON. POST FRONTAL SHOWERS ARE LINING
UP EARLY THIS MORNING THROUGH WHIDBEY ISLAND THROUGH KPAE, MOVING
GENERALLY TOWARD THE SE. RA/SN SHOWERS CANNOT BE RULED OUT EARLY
THIS MORNING. FOG HAS SETTLED INTO CENTRAL PUGET SOUND AND IS LIKELY
TO REMAIN IN PLACE WITH LOW CIGS UNTIL AROUND 18-19Z. PROBABILITIES
OF CIGS BELOW 030 ARE BETWEEN 35-45% FOR AREAS KSEA SOUTH. WINDS
WILL REMAIN LIGHT THROUGHOUT THE PERIOD, INCREASING ALONG THE COAST
AS ONSHORE FLOW KICKS BACK IN AROUND MIDDAY.
KSEA...SIGNIFICANTLY REDUCED VISBYS AND CIGS ARE PRESENT AT THE
TERMINAL EARLY THIS MORNING DUE TO FOG SETTING UP IN THE WAKE OF THE
SNOW AND MOISTURE. SOME ADDITIONAL ROUNDS OF DRIZZLE (AND AROUND A
15-20% CHANCE OF LIGHT -RA/SN) ARE POSSIBLE THROUGH 16Z THIS
MORNING. FOG WILL REMAIN IN PLACE UNTIL 18-19Z BEFORE CONDITIONS
REBOUND INTO MVFR TO VFR CRITERIA. EXPECT SOUTHERLY WINDS THROUGHOUT
THE PERIOD.
21
MARINE
SURFACE RIDGING WILL BUILD TODAY AND GRADUALLY REDUCE AREA
PRECIPITATION DOWN TO ISOLATED SHOWERS THIS MORNING. THIS WILL LEAD
TO INCREASING ONSHORE FLOW OVER THE COASTAL WATERS AND IN THE STRAIT
OF JUAN DE FUCA TODAY. THIS MORNING, EXPECT SOME MARINE FOG IN
CENTRAL PUGET SOUND, DISSIPATING LIKELY AFTER 18Z. INHERITED SCA
PRODUCTS WILL REMAIN IN PLACE FOR STRONGER WINDS ALONG THE COAST AND
IN THROUGH THE STRAIT OF JUAN DE FUCA. THE RIDGE WILL SHIFT ONSHORE
TONIGHT AND SUNDAY AS A STRONG WARM FRONT APPROACHES THE OFFSHORE
WATERS. THE WARM FRONT WILL LIFT NORTHWARD ACROSS AREA WATERS MONDAY
INTO TUESDAY FOR INCREASING WINDS AND SEAS.
21
HYDROLOGY
RIVER FLOODING CONTINUES FOR RIVERS ACROSS THE CHEHALIS BASIN
THIS MORNING. RIVERS CURRENTLY IN FLOOD STAGE INCLUDE THE
NEWAUKUM RIVER NEAR CHEHALIS, THE SKOOKUMCHUCK RIVER NEAR
BUCODA, AND THE CHEHALIS RIVER NEAR GRAND MOUND. THE CHEHALIS
RIVER AT PORTER CONTINUES TO RISE AND WILL LIKELY REACH FLOOD
STAGE BY LATE THIS MORNING. MEANWHILE, THE DESCHUTES RIVER NEAR
RAINIER HAS CRESTED JUST BELOW FLOOD STAGE OVERNIGHT. WITH
WIDESPREAD PRECIPITATION ENDING ACROSS THE AREA, EXPECT RIVERS
TO CREST TODAY INTO SUNDAY AND TO START RECEDING.
ATTENTION WILL THEN TURN TO AN ATMOSPHERIC RIVER EXPECTED TO
MOVE INLAND TO THE NORTH OF THE REGION EARLY NEXT WEEK BEFORE
GRADUALLY SAGGING SOUTHWARD INTO OUR AREA. HIGHER SNOW LEVELS
AND RAIN ON RECENT SNOWS IN THE MOUNTAINS COULD BRING ADDITIONAL
FLOODING CONCERNS TO PORTIONS OF THE AREA AS SEVERAL RIVERS ARE
FORECAST TO RISE INTO ACTION STAGE. FOR NOW, THE ONLY RIVER
FORECAST TO REACH FLOOD STAGE IS THE SKOKOMISH RIVER- BUT RIVER
FORECASTS WILL BEAR WATCHING OVER THE COMING DAYS.
14
SEW WATCHES/WARNINGS/ADVISORIES
WA...WINTER STORM WARNING UNTIL 11 AM PDT THIS MORNING FOR CASCADES
OF PIERCE AND LEWIS COUNTIES-CASCADES OF SNOHOMISH AND
NORTHERN KING COUNTIES-CASCADES OF SOUTHERN KING COUNTY.
FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR CASCADES OF PIERCE
AND LEWIS COUNTIES-FOOTHILLS AND VALLEYS OF THURSTON AND
LEWIS COUNTIES-LOWLANDS OF LEWIS AND SOUTHERN THURSTON
COUNTIES-OLYMPIA AND SOUTHERN PUGET SOUND-WILLAPA AND
BLACK HILLS.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING 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.
PZ...SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR CENTRAL
U.S. WATERS STRAIT OF JUAN DE FUCA-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 3 PM PDT THIS AFTERNOON FOR EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
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