727
FXUS66 KSEW 112232
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
332 PM PDT SAT APR 11 2026
SYNOPSIS
UPPER LEVEL LOW OFF THE NORTHERN CALIFORNIA COAST TONIGHT SLOWLY
MOVING INLAND AND WEAKENING SUNDAY AND SUNDAY NIGHT. MOISTURE
ROTATING AROUND THE LOW MAINLY STAYING SOUTH OF WESTERN
WASHINGTON. PUGET SOUND CONVERGENCE ZONE FORMING MONDAY OVER
CENTRAL PUGET SOUND DRIFTING NORTH LATER MONDAY INTO MONDAY
NIGHT. RAIN OUT AHEAD OF NEXT FRONT ARRIVING TUESDAY. FRONT
MOVING THROUGH TUESDAY NIGHT WITH BREEZY CONDITIONS PLUS
POSSIBLE HEAVY MOUNTAIN SNOW. UPPER LEVEL LOW OVER WESTERN
WASHINGTON WEDNESDAY. DRYING NORTHERLY FLOW ALOFT DEVELOPING
THURSDAY.
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/
SATELLITE IMAGERY SHOWS UPPER LEVEL LOW STILL SPINNING OFF THE
NORTHERN CALIFORNIA COAST. BANDS OF MOISTURE ROTATING AROUND
THE LOW WITH THE LATEST ONE JUST REACHING THE CENTRAL PUGET
SOUND AT 3 PM/22Z. PREVIOUS MOISTURE BAND BRINGING RAIN BETWEEN
BELLINGHAM AND FORKS. REST OF THE MOISTURE SPINNING AROUND LOW
SOUTH OF THE AREA. WITH ALL THE CLOUD COVER TEMPERATURES WERE
ONLY IN THE UPPER 40S TO MID 50S.
UPPER LEVEL LOW SLOWLY MOVING EAST TONIGHT INTO SUNDAY. CURRENT
BANDS OF MOISTURE OVER WESTERN WASHINGTON ROTATING OUT OF THE
AREA TONIGHT. AS THE LOW MOVES EAST THE FLOW ALOFT WILL BEGIN
TO CUT OFF THE MOISTURE FROM GETTING AS FAR NORTH AS WESTERN
WASHINGTON. AIR MASS WILL BE SLIGHTLY UNSTABLE WITH WEAK
TROUGHINESS OVER THE AREA KEEPING A CHANCE OR SLIGHT CHANCE OF
SHOWERS IN THE FORECAST SUNDAY INTO SUNDAY NIGHT. WITH PLENTY OF
CLOUD COVER LOWS TONIGHT STAYING IN THE 40S. A LITTLE LESS
CLOUD COVER SUNDAY WARMING HIGHS INTO THE MID 50S TO LOWER 60S.
LOW WEAKENING INTO AN UPPER LEVEL TROUGH SUNDAY NIGHT WITH THE
FLOW ALOFT OVER WESTERN WASHINGTON TURNING NORTHWESTERLY. AIR
MASS STILL SLIGHTLY UNSTABLE FOR A CONTINUING CHANCE OF SHOWERS.
LOWS ONCE AGAIN IN THE 40S.
WEST NORTHWESTERLY FLOW ALOFT MONDAY WITH THE LOW LEVEL FLOW
GOING ONSHORE. PUGET SOUND CONVERGENCE ZONE DEVELOPING IN THE
MORNING OVER THE CENTRAL PUGET SOUND WITH THE CONVERGENCE ZONE
CONTINUING INTO THE AFTERNOON HOURS. OUTSIDE OF THE CONVERGENCE
ZONE SHOWER ACTIVITY DRYING UP. AT LEAST MOSTLY CLOUDY SKIES
WITH THE ONSHORE FLOW WILL KEEP HIGHS IN THE MID 50S.
CONVERGENCE ZONE DISSIPATING MONDAY NIGHT. RAIN OUT AHEAD OF
THE NEXT FRONTAL SYSTEM STILL MOSTLY TO THE WEST. WARM FRONT
COULD NICK THE NORTH COAST. LOWS IN THE 40S. FELTON
LONG TERM /TUESDAY THROUGH SATURDAY/
EXTENDED MODELS IN GOOD AGREEMENT WITH A STRONG FOR APRIL FRONT
MOVING THROUGH WESTERN WASHINGTON TUESDAY NIGHT. RAIN OUT AHEAD
OF THE FRONT SPREADING OVER THE AREA DURING THE DAY. WINDS
PICKING UP IN THE AFTERNOON WITH BREEZY/WINDY CONDITIONS TUESDAY
NIGHT. NOT EXPECTING RECORD LOW MAXIMUM TEMPERATURES DUE TO THE
SHORT COLD SPELL IN 2022. HIGHS ONLY NEAR 50. SNOW LEVELS
DROPPING TO NEAR 3000 FEET WITH HEAVY SNOW IN THE MOUNTAINS
POSSIBLE TUESDAY NIGHT.
COOL UPPER LEVEL LOW DROPPING DOWN OVER WESTERN WASHINGTON
WEDNESDAY AND WEDNESDAY NIGHT. AIR MASS UNSTABLE ENOUGH TO
INCLUDE A CHANCE OF THUNDERSTORMS ALONG WITH THE SHOWERS. HIGHS
REMAINING NEAR 50.
UPPER LEVEL LOW KICKING OUT OF THE AREA WITH DRYING NORTHERLY
FLOW ALOFT DEVELOPING THURSDAY. WEAK UPPER LEVEL RIDGE TRYING
TO BUILD OVER THE AREA THURSDAY NIGHT INTO SATURDAY. HIGHS IN
THE MID 50S THURSDAY WARMING TO THE MID 50S TO LOWER 60S
SATURDAY.
WEDNESDAY AND ESPECIALLY THURSDAY MORNING ON THE COOL SIDE WITH
FROST ADVISORIES FOR THE COLDER LOCATIONS LIKE THE SOUTHWEST
INTERIOR POSSIBLE BOTH MORNINGS. LOWS WARMING SLIGHTLY FRIDAY
AND SATURDAY MORNING.
AVIATION
SOUTHERLY WINDS ALOFT BECOMING VARIABLE LATE OVERNIGHT INTO SUNDAY.
SHOWERS HAVE BROUGHT A MIXED-BAG OF CIGS FROM VFR TO IFR THIS
AFTERNOON. THIS TREND WILL LIKELY PERSIST OVERNIGHT INTO SUNDAY
(WITH THE POSSIBILITY FOR LIFR CONDITIONS) AS WELL. CAN'T RULE OUT
AREAS OF FOG DEVELOPING EARLY SUNDAY MORNING, ESPECIALLY FOR
TERMINALS IN THE SW INTERIOR (KOLM). A RETURN TO VFR IS IN THE CARDS
ON SUNDAY AFTERNOON AS CEILINGS LIFT.
KSEA...
MVFR CONDITIONS HAVE CONTINUED INTO THE AFTERNOON BUT SHOULD
IMPROVE TO TO VFR BY 00Z SUNDAY. SOUTHERLY WINDS TURNING NORTHERLY
AFTER 00Z AS WELL AND ARE LIKELY TO REMAIN THAT WAY OVERNIGHT INTO
SUNDAY MORNING. LOW CEILINGS ARE FAVORED TO REDEVELOP TONIGHT AS A
THE NBM SUGGESTS A 70% CHANCE OF MVFR CIGS DEVELOPING BY 12Z AND A
NEAR 40% CHANCE OF LIFR CONDITIONS SETTING IN AROUND THE SAME TIME.
A RETURN TO VFR LIKELY BY 20Z SUNDAY.
MCMILLIAN
MARINE
SURFACE LOW PRESSURE WILL MOVE SOUTH OF THE COASTAL WATERS THIS
EVENING. SEAS ARE TO REMAIN BENIGN TONIGHT BUT A SCA HAS BEEN ISSUED
STARTING SUNDAY EVENING FOR THE CENTRAL/EASTERN STRAIT AS WESTERLY
WIND FORECASTS HAVE INCREASED IN THE LATEST UPDATE. A STRONGER
FRONTAL SYSTEM ARRIVING TUESDAY INTO WEDNESDAY WILL LIKELY YIELD
MORE WIDESPREAD HEADLINES WITH ENHANCED WINDS AND SEAS.
COASTAL SEAS 4 TO 6 FEET THROUGHOUT THE WEEKEND. SEAS WILL THEN
START TO BUILD UPWARDS TO 8 TO 10 FEET BY TUESDAY EVENING AND
REMAINING ELEVATED THROUGH THURSDAY.
MCMILLIAN
HYDROLOGY
NO RIVER FLOODING THE NEXT 7 DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 5 PM SUNDAY TO 11 AM PDT MONDAY FOR
CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE
U.S. WATERS STRAIT OF JUAN DE FUCA.
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