354
FXUS66 KSEW 232110
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
210 PM PDT WED APR 23 2025
SYNOPSIS
HIGH PRESSURE WILL BUILD OVER THE REGION THROUGH
THURSDAY, WITH DRY AND WARMING CONDITIONS. COOLER AND WETTER
WEATHER WILL MOVE IN LATER THIS WEEKEND, WITH A RETURN OF DRIER
AND WARMER WEATHER POSSIBLE TOWARDS THE LATTER HALF OF NEXT WEEK.
SHORT TERM /TONIGHT THROUGH SATURDAY/
UPPER LEVEL RIDGING WILL
CONTINUE TO BUILD OVER THE REGION THROUGH THURSDAY FOR DRY AND
WARM CONDITIONS. TEMPERATURES THIS AFTERNOON HAVE BEEN WARMING
STEADILY INTO THE MID TO UPPER 60S, WITH SOME LOCALIZED SPOTS IN
70S. TEMPERATURES WILL WARM A TOUCH MORE ON THURSDAY, WITH MOST OF
THE INTERIOR LOCATIONS SEEING TEMPERATURES IN THE LOWER 70S -
AREAS ALONG THE WATER WILL SEE HIGHS CLOSE TO THE MID 60S.
A WEAK TROUGH OFFSHORE WILL START TO INCREASE CLOUD COVER SLIGHTLY HEADING
INTO FRIDAY, AS A CUTOFF LOW CONTINUES TO MOVE SOUTHWARD INTO
CALIFORNIA. LATEST ENSEMBLE GUIDANCE HAS CONTINUED THIS TRACK OF A
SOUTHWARD PROGRESSION, WHICH WOULD DECREASE PRECIPITATION CHANCES
FOR WESTERN WASHINGTON. HIGH TEMPERATURES ON FRIDAY WILL CONTINUE
TO BE THE UPPER 60S/LOWER 70S.
A SPLIT FLOW REGIME LOOKS TO SET UP HEADING INTO THE WEEKEND, WITH
SATURDAY LOOKING TO BE MAINLY DRY AND TEMPERATURES IN THE LOW TO
MID 60S.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
SPLIT FLOW WILL SLIGHTLY
DIFFER AS A UPPER TROUGH OPENS WAY FOR PRECIPITATION CHANCES ON
SUNDAY. ENSEMBLES ARE HAVING A DIFFICULT TIME GRASPING ON THE
STRENGTH AND SPREAD OF PRECIPITATION AS IT SEEMS WEAK, BUT
OVERALL, IT LOOKS GENERALLY LIGHT, IF ANY PRECIP, ON SUNDAY.
SHOWERS MAY LINGER THROUGH MIDWEEK BEFORE DRIER WEATHER RETURNS.
MAZURKIEWICZ
AVIATION
AN UPPER LEVEL RIDGE AXIS OVER THE COASTAL WATERS WILL
SHIFT ONSHORE TONIGHT WITH NORTH TO NORTHWEST FLOW ALOFT BECOMING
LIGHT SOUTHERLY OVERNIGHT. THE LOW LEVEL FLOW REMAINS NORTHERLY. THE
AIR MASS IS DRY AND STABLE. MOSTLY CLEAR SKIES EXPECTED THROUGH THE
PERIOD EXCEPT FOR SOME PATCHY STRATUS ALONG THE COAST AND LOCALLY IN
THE CHEHALIS GAP ON THURSDAY MORNING.
KSEA...VFR. SURFACE WINDS NORTH/NORTHWESTERLY 5 TO 8 KNOTS BECOMING
LIGHT NORTHEASTERLY TONIGHT THEN NORTH/NORTHWESTERLY 7 TO 10 KNOTS
ONCE AGAIN THURSDAY AFTERNOON. 27
MARINE
A SURFACE RIDGE CENTERED OFFSHORE WILL WEAKEN THROUGH
TOMORROW. A BROAD AREA OF WEAK SURFACE LOW PRESSURE WILL DEVELOP
LATE IN THE WEEK OVER THE PACIFIC NORTHWEST WHILE HIGH PRESSURE
REMAINS CENTERED WELL OFFSHORE. THIS WILL LEAD TO AN OVERALL
INCREASE IN ONSHORE FLOW LEADING INTO THE UPCOMING WEEKEND. THE END
RESULT WILL LIKELY BE A PERIOD OF SMALL CRAFT ADVISORY WINDS ACROSS
THE COASTAL WATERS AS WELL AS THE CENTRAL/EAST PORTIONS OF THE
STRAIT. 27
HYDROLOGY
NO RIVER FLOODING IS EXPECTED OVER THE NEXT 7 DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
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