994
FXUS66 KSEW 170348
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
848 PM PDT SAT MAY 16 2026
SYNOPSIS
A COLD UPPER LEVEL TROUGH WILL CONTINUE TO PASS
THROUGH WESTERN WASHINGTON THROUGH SUNDAY MORNING AS SHOWERS
TAPER OFF TONIGHT. AN UPPER LEVEL RIDGE WILL BUILD OFFSHORE
THEREAFTER, WITH WESTERN WASHINGTON REMAINING ON THE BACKSIDE OF
THE RIDGE THROUGHOUT MUCH OF NEXT WEEK.
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/
LINGERING SHOWERS
WILL CONTINUE TO TAPER OFF TONIGHT INTO EARLY SUNDAY MORNING.
THE WINTER WEATHER ADVISORY CONTINUES GENERALLY SOUTH OF I-90
ABOVE 4000 FEET INTO TONIGHT. OTHERWISE, COOLER CONDITIONS INTO
SUNDAY MORNING MAY ALLOW FOR PATCHY FROST TO DEVELOP AROUND
SHELTON AND SOUTH OF OLYMPIA.
THE UPPER LEVEL TROUGH WILL SHIFT SOUTHEASTWARD BY SUNDAY
MORNING, WITH AN UPPER LEVEL RIDGE BUILDING OFFSHORE. CONDITIONS
ACROSS MUCH OF WESTERN WASHINGTON WILL DRY OUT DESPITE A MOSTLY
CLOUDY MORNING AND SOME SUN BREAKS IN THE AFTERNOON. WRAP
AROUND MOISTURE MAY RESULT IN LINGERING SHOWER ACTIVITY ACROSS
THE NORTH CASCADES WITH LITTLE TO NO ACCUMULATION. COOLER
TEMPERATURES WILL CONTINUE ACROSS THE REGION ON SUNDAY, WITH
HIGHS PEAKING IN THE LOW 60S ACROSS MUCH OF THE LOWLANDS.
LOW CLOUDS ARE FAVORED TO DEVELOP ACROSS MUCH OF THE LOWLANDS
AGAIN INTO MONDAY MORNING AS HIGH PRESSURE BUILDS INTO THE
REGION. THE CLOUDS ARE FAVORED TO BREAK UP FOR MOST AREAS BY THE
AFTERNOON, WITH NEAR NORMAL TEMPERATURES AND MOSTLY DRY
CONDITIONS FOR MONDAY.
LONG TERM /TUESDAY THROUGH SATURDAY/
ENSEMBLES REMAIN IN
GOOD AGREEMENT OVER HIGH PRESSURE REMAINING SITUATED OFFSHORE
THROUGH MUCH OF NEXT WEEK. A SERIES OF LOW PRESSURE SYSTEMS WILL
MOVE INLAND NEXT WEEK, BUT ARE FAVORED TO SPLIT APART OR STAY
NORTH OF THE WASHINGTON/CANADA BORDER. CONDITIONS ACROSS WESTERN
WASHINGTON ARE FAVORED TO REMAIN MOSTLY DRY THROUGH THE
FORECAST PERIOD WITH NEAR NORMAL TEMPERATURES.
JD/15
AVIATION
THE TROUGH CONTINUES TO MOVE SOUTH, GENERALLY
ENDING SHOWERS FOR MOST OF WESTERN WASHINGTON. AREAS OF THE
SOUTHERN WASHINGTON CASCADES WILL SEE SHOWERS CONTINUE OVER THE
NEXT SEVERAL HOURS. AREAS OF NORTHERN PUGET SOUND ARE GENERALLY
WEST TO NORTHWEST, WITH SOUTHWESTERLY WINDS RETURNING TO CENTRAL
AND SOUTHERN PUGET SOUND. WINDS OUTSIDE OF THIS AREA WILL
REMAIN OUT OF THE SOUTHWEST- NORTHWEST 5-10 KT WITH A FEW GUSTS
TO 20 KT FOR TERMINALS NEAR WATERS. VFR/MVFR CEILINGS ARE LIKELY
SUNDAY MORNING BEFORE CLEARING IN THE AFTERNOON.
KSEA...SHOWERS HAVE ENDED FOR THE TERMINAL AND IMMEDIATE VICINITY.
SURFACE WINDS HAVE RETURNED TO A SOUTH TO SOUTHWESTERLY, AND WILL
LINGER AS SUCH THROUGHOUT THE NIGHT BETWEEN 4-7 KTS. MVFR CIGS
POSSIBLE BETWEEN 13Z-16Z TOMORROW MORNING BEFORE RETURNING TO VFR IN
THE AFTERNOON. NORTHERLY WINDS 4-6 KTS RETURNING AFTER 18Z SUNDAY,
LINGERING THROUGH THE REST OF THE TAF PERIOD.
21
MARINE
GUSTY WINDS WILL CONTINUE WITH THE ONSHORE FLOW FOR
THE COASTAL WATERS, STRAIT OF JUAN DE FUCA AND ADMIRALTY INLET.
THERE REMAINS A CHANCE OF A BRIEF GALE GUST IN THE EASTERN
SECTION OF THE STRAIT EARLY THIS EVENING. THE ONSHORE PUSH WILL
DIMINISH LATE TONIGHT/SUNDAY MORNING. THE PATTERN WILL REMAIN
ONSHORE AS HIGH PRESSURE BUILDS BACK OVER THE WATERS SUNDAY.
ANOTHER WEAK FRONT WILL PASS THROUGH MONDAY INTO TUESDAY.
CONTINUAL PUSHES OF WINDS DOWN THE STRAIT OF JUAN DE FUCA REMAIN
LIKELY THROUGH MIDWEEK.
SEAS OF 8-11 FT WILL CONTINUE IN THE COASTAL WATERS THROUGH EARLY
SUNDAY (WITH ROUGH BAR CONDITIONS). THEY WILL DROP BACK TO 6-8 FT
LATER SUNDAY THROUGH TUESDAY BEFORE INCREASING TO 8-10 FT WEDNESDAY,
AND THEN DROPPING TO 5-6 FT THROUGH THE END OF THE WEEK.
HPR/21
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...WINTER WEATHER ADVISORY UNTIL 1 AM PDT SUNDAY FOR CASCADES OF
PIERCE AND LEWIS COUNTIES-CASCADES OF SOUTHERN KING
COUNTY.
PZ...SMALL CRAFT ADVISORY UNTIL 3 AM PDT SUNDAY FOR ADMIRALTY INLET-
CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE
U.S. WATERS STRAIT OF JUAN DE FUCA-GRAYS HARBOR BAR.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT PDT TONIGHT FOR WEST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 2 AM PDT SUNDAY 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.
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