154  
FXUS66 KSEW 221509  
AFDSEW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SEATTLE WA  
809 AM 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.  
 
 
   
UPDATE  
A FEW AREAS OF PATCHY FOG WILL BURN OFF QUICKLY THIS  
MORNING. OTHERWISE A PLEASANT DAY IS ON TAP ACROSS WESTERN  
WASHINGTON. THE CURRENT FORECAST IS ON TRACK AND NO UPDATES ARE  
PLANNED THIS MORNING. -WOLCOTT-  
 
 
   
SHORT TERM /TODAY THROUGH THURSDAY/  
CLOUD COVER WILL CONTINUE  
TO DECREASE EARLY THIS MORNING AS A DRY SHORTWAVE TROUGH DIGS  
SOUTHWARD INTO THE PACIFIC NORTHWEST AND HIGH PRESSURE BUILDS  
OFFSHORE. CLEARING SKIES WILL ALLOW TEMPERATURES TO DIP INTO THE  
30S FOR MOST AREAS THIS MORNING WITH PATCHES OF FOG AND FROST  
POSSIBLE, ESPECIALLY FOR AREAS SOUTH OF THE PUGET SOUND.  
 
A RIDGE OF HIGH PRESSURE WILL MOVE INLAND LATER TODAY THROUGH  
THURSDAY, BRINGING IN A GRADUAL WARMING TREND ALONGSIDE DRY AND  
SUNNY CONDITIONS. TEMPERATURES WILL RISE TO WELL ABOVE NORMAL BY  
THURSDAY, WITH MOST LOWLAND AREAS EAST AND SOUTH OF THE PUGET  
SOUND SEEING HIGHS IN THE 70S. CLOUDS WILL SLOWLY START TO MOVE  
BACK INTO THE REGION LATER ON THURSDAY AS A TROUGH SLOWLY  
APPROACHES THE COAST AND THE UPPER RIDGE AXIS SHIFTS TO THE EAST  
OF THE CASCADES.  
   
LONG TERM /FRIDAY THROUGH MONDAY/  
A CUTOFF LOW IS ON TRACK TO  
MOVE INLAND OVER NORTHERN CALIFORNIA ON FRIDAY, ADVECTING MOISTURE  
NORTHWARD TOWARDS WESTERN WASHINGTON. PRECIPITATION WILL BE  
HIGHLY DEPENDENT ON THE TRACK OF THE LOW PRESSURE SYSTEM, WITH  
ENSEMBLES MAINTAINING A CHANCE OF SHOWERS ACROSS THE AREA ON  
FRIDAY. CHANCES FOR LIGHT PRECIPITATION ALONGSIDE COOLER  
TEMPERATURES CONTINUE THROUGH THE WEEKEND, WITH ENSEMBLES  
MAINTAINING TROUGHING OVER THE REGION THROUGH SUNDAY. RIDGING IS  
FAVORED TO RETURN BY EARLY NEXT WEEK, ALTHOUGH FORECAST MODELS  
SHOW DIFFERENCES OVER THE TIMING AND STRENGTH OF THE NEXT INCOMING  
SYSTEM TO START OFF NEXT WEEK.  
 
15  
 
 
   
AVIATION  
UPPER RIDGING CENTERED OFFSHORE WILL CONTINUE TO  
BUILD INTO THE REGION TODAY WITH NORTH TO NORTHWEST FLOW ALOFT.  
THE LOW LEVEL FLOW IS NORTHERLY. APART FROM PATCHY STRATUS ACROSS  
NORTH PUGET SOUND AND OUTLYING RIVER VALLEYS THIS MORNING, VFR  
CONDITIONS WILL PREVAIL AREAWIDE TODAY.  
 
KSEA...VFR. SURFACE WINDS LIGHT AND VARIABLE EARLY BECOMING  
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.  
 
 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab WA Page
Main Text Page