309
FXUS66 KSEW 222048
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
145 PM PDT TUE APR 22 2025
SYNOPSIS
DRY AND WARMING CONDITIONS ARE EXPECTED THROUGH THURSDAY
AS HIGH PRESSURE MOVES INTO THE REGION. COOLER CONDITIONS AND
PRECIPITATION CHANCES WILL RETURN TO THE FORECAST FRIDAY INTO THE
WEEKEND.
SHORT TERM /TONIGHT THROUGH THURSDAY/
DRY AND MOSTLY SUNNY
CONDITIONS DOMINATE ACROSS WESTERN WA THIS AFTERNOON AS A RIDGE OF
HIGH PRESSURE NOSES INTO THE REGION. ANOTHER COOL NIGHT IS
EXPECTED OVERNIGHT WITH AREAS OF ISOLATED FOG AND FROST POSSIBLE
AGAIN. THAT SAID, TEMPERATURES ARE EXPECTED TO BE SLIGHTLY HIGHER,
LIMITING THE FROST EXTENT EVEN MORE THAN THIS MORNING.
THE RIDGE WILL SHIFT EAST ACROSS THE REGION WEDNESDAY AND
THURSDAY ALLOWING FOR A SIGNIFICANT WARM UP. BY THURSDAY,
AFTERNOON HIGHS WILL REACH INTO THE LOW TO MID 70S ACROSS THE
REGION.
LONG TERM /FRIDAY THROUGH TUESDAY/
BY FRIDAY, A TROUGH OFF
THE COAST WILL ELONGATE AND CLUSTER ANALYSIS NOW SLIGHTLY FAVORS A
CUTOFF LOW BRINGING THE BULK OF THE ENERGY SOUTH OF THE REGION
FRIDAY THROUGH SUNDAY AND LEAVING WESTERN WA WARMER AND SOMEWHAT
DRIER. STILL THERE IS A ~40% CHANCE THAT THE TROUGH HOLDS TOGETHER
AND BRINGS MORE OF THE ENERGY OUR WAY LEADING TO A WETTER AND
COOLER SOLUTION.
THERE REMAINS A SIGNAL IN ENSEMBLE GUIDANCE FOR WEAK AND
POTENTIALLY TRANSIENT RIDGING IN THE MONDAY/TUESDAY TIMEFRAME NEXT
WEEK. ALL IN ALL, LITTLE IMPACT IS EXPECTED AT THIS TIME.
-WOLCOTT-
AVIATION
UPPER RIDGING CENTERED OFFSHORE WILL CONTINUE TO BUILD
INTO THE REGION WITH NORTH TO NORTHWEST FLOW ALOFT. THE LOW
LEVEL FLOW IS NORTHERLY. VFR CONDITIONS PREVAIL. PATCHY STRATUS ON
WEDNESDAY MORNING WILL BE RESTRICTED TO OUTLYING RIVER VALLEYS, THE
CHEHALIS GAP, AND PORTIONS OF THE IMMEDIATE COAST.
KSEA...VFR. SURFACE WINDS NORTHERLY 8 TO 11 KNOTS MIDDAY THEN
SHIFTING LIGHT NORTHEASTERLY TONIGHT. 27
MARINE
A BROAD SURFACE RIDGE CENTERED OFFSHORE WILL GRADUALLY
WEAKEN INTO THURSDAY. A WEAK TROUGH MOVING INTO THE OREGON OFFSHORE
WATERS LATE IN THE WEEK WILL INCREASE NORTHWESTERLIES OVER THE
COASTAL WATERS, BUT WILL OTHERWISE PRODUCE LITTLE IMPACT ACROSS AREA
WATERS. 27
HYDROLOGY
NO RIVER FLOODING IS EXPECTED OVER THE NEXT 7 DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
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