040
FXUS66 KSEW 230306
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
806 PM PDT FRI MAY 22 2026
SYNOPSIS
WEAK HIGH PRESSURE REMAINS IN PLACE TODAY, BUT WILL BECOME MORE
ZONAL INTO THE WEEKEND. ONSHORE FLOW WILL INCREASE OVER THE
NEXT SEVERAL DAYS. A SYSTEM ARRIVING ON MEMORIAL DAY WILL BRING
WIDESPREAD RAIN AND COOLER TEMPERATURES TO THE REGION. THE REST
OF THE FRONT WILL MOVE THROUGH ON TUESDAY, KEEPING SHOWERS IN
THE FORECAST. WEAK RIDGING IS POSSIBLE THROUGH THE SECOND HALF
OF THE WEEK.
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/
THE LATEST FORECAST REMAINS ON TRACK THIS EVENING WITH NO
UPDATES OUTSIDE OF MARINE HEADLINES. WEAK HIGH PRESSURE ALOFT
WILL TRANSITION TO MORE ZONAL, ONSHORE FLOW THROUGH THE WEEKEND.
THIS WILL ENABLE A DEEPER PUSH OF MARINE STRATUS INTO THE
INTERIOR EACH OF THE NEXT FEW MORNINGS. WHILE THE ONSHORE PUSH
LOOKS A BIT MORE EXTENSIVE AND WILL LIKELY LINGER A BIT LONGER
THROUGH THE MORNING SATURDAY, THERE'S LIKELY TO BE SOME
IMPROVEMENT IN THE AFTERNOON. THIS WILL BRING SOME SUNSHINE TO
THE INTERIOR AND AFTERNOON HIGHS IN THE UPPER 60S TO AROUND 70
EACH DAY. THIS WILL MAINTAIN ONLY MINOR HEATRISK ACROSS MOST OF
THE LOWLANDS. THE ONSHORE FLOW WILL ALSO STRENGTHEN THE WESTERLY
WINDS THROUGH THE STRAIT OF JUAN DE FUCA OVER THE WEEKEND.
LONG TERM /MONDAY THROUGH FRIDAY/
THE ZONAL FLOW WILL OPEN THE DOOR TO THE NEXT SYSTEM ARRIVING
LATE SUNDAY NIGHT INTO MONDAY. THIS WILL BRING BREEZY, COOL, AND
WET CONDITIONS TO WESTERN WASHINGTON FOR THE MEMORIAL DAY
HOLIDAY. AMOUNTS OF AROUND A HALF INCH OF RAIN IN THE LOWLANDS
AND ONE TO ONE AND A HALF INCHES IN THE MOUNTAINS ARE EXPECTED.
ADDITIONALLY, THOUGH THE INSTABILITY LATE MONDAY AFTERNOON AND
EVENING LOOKS RATHER MODEST, THERE'S STILL AROUND A 10-15%
CHANCE OF A FLASH OF LIGHTNING OR TWO ESPECIALLY NEAR THE COAST
OR FROM PUGET SOUND SOUTHWARD. IN ADDITION TO THE RAIN, WE'LL
SEE RATHER BREEZY WINDS WITH GUSTS UP TO 20-30 MPH ACROSS MUCH
OF THE AREA AS THIS WEATHER SYSTEM MOVES THROUGH. WHILE THESE
SPEEDS ARE NOT GENERALLY STRONG ENOUGH TO CAUSE WIDESPREAD
IMPACTS, UNSECURED TENTS OR OUTDOOR EQUIPMENT COULD BE IMPACTS.
WITH THIS COOLER AIR MASS IN PLACE, TEMPERATURES ARE UNLIKELY
TO CLIMB OUT OF THE 60S. SHOWERS LINGER EARLY TUESDAY AS THE
UPPER TROUGH MOVES PAST THE AREA, WITH A RETURN TO DRY
CONDITIONS LATE TUESDAY THROUGH MIDWEEK AS WEAK HIGH PRESSURE
AGAIN REBUILDS.
AVIATION
AN UPPER LEVEL RIDGE CENTERED OFFSHORE WILL WEAKEN OVERNIGHT INTO
SATURDAY WITH WEST TO NORTHWEST FLOW ALOFT CONTINUING. INCREASING
LOW LEVEL ONSHORE FLOW AHEAD OF A WEAK SYSTEM MOVING INTO BRITISH
COLUMBIA WILL BRING COASTAL STRATUS INTO THE INTERIOR LOWLANDS
OVERNIGHT. WIDESPREAD IFR OR LOW MVFR CEILINGS ARE EXPECTED WEST OF
THE CASCADES ON SATURDAY MORNING. THE STRATUS IS EXPECTED TO
GRADUALLY LIFT AND SCATTER BY 21Z SATURDAY FOR THE INTERIOR AREAS,
BUT WILL LINGER ALONG THE COAST FOR THE ENTIRETY OF SATURDAY.
KSEA...VFR IS EXPECTED THROUGH THIS EVENING. IFR OR LOW MVFR STRATUS
WILL REACH THE TERMINAL BY AROUND 10Z SATURDAY AND PERSIST INTO
MIDDAY SATURDAY BEFORE SCATTERING OUT MID-AFTERNOON. SURFACE WINDS
WEST TO NORTHWEST 7 KNOTS OR LESS WILL BACK TO SOUTHWESTERLY
LATE THIS EVENING AND INCREASE 7 TO 10 KNOTS SATURDAY MORNING.
27
MARINE
SURFACE HIGH PRESSURE CENTERED WELL OFFSHORE WILL CONTINUE TO
PRODUCE ONSHORE FLOW INTO THE WEEKEND. A SYSTEM PASSING WELL NORTH
OF THE WATERS WILL INCREASE ONSHORE TONIGHT INTO SATURDAY. THIS WILL
LEAD TO ADVISORY LEVEL WESTERLIES IN THE CENTRAL/EAST STRAIT TONIGHT
AND NEAR GALE WESTERLIES SATURDAY EVENING. A GALE WATCH HAS BEEN
ISSUED ACROSS THE CENTRAL AND EAST STRAIT OF JUAN DE FUCA FOR
THE SATURDAY EVENING WESTERLY PUSH. THE OFFSHORE RIDGE WILL
WEAKEN AND SHIFT SOUTHWARD ON SUNDAY AS A FRONTAL SYSTEM
ASSOCIATED WITH A VERTICALLY STACKED LOW WEST OF HAIDA GWAII
APPROACHES THE AREA. THIS SYSTEM IS EXPECTED TO PRODUCE ADVISORY
LEVEL WINDS ACROSS MUCH OF THE WATERS MONDAY ALONG WITH SEAS
BUILDING TO AT OR ABOVE 10 FEET OVER THE COASTAL WATERS MONDAY
INTO TUESDAY. WEAK SURFACE RIDGING REBUILDS OFFSHORE LATER
TUESDAY INTO WEDNESDAY.
27/15
HYDROLOGY
THE DAILY HYDROLOGY DISCUSSION HAS ENDED UNTIL THE START OF THE
NEXT RAINY SEASON; IT WILL ONLY BE UPDATED DURING THIS TIME AS
NEEDED.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 3 AM PDT SATURDAY FOR CENTRAL U.S.
WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S. WATERS
STRAIT OF JUAN DE FUCA.
GALE WATCH FROM SATURDAY MORNING THROUGH LATE SATURDAY NIGHT
FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY FROM 5 AM SATURDAY TO 2 AM PDT SUNDAY FOR
COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO
60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE
10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER 10 TO 60 NM.
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