966  
FXUS66 KSEW 060257  
AFDSEW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SEATTLE WA  
757 PM PDT SAT JUL 5 2025  
   
SYNOPSIS
 
A WARMING TREND WILL BEGIN THE NEW WEEK AS AN UPPER  
RIDGE STRENGTHENS OVER WESTERN WASHINGTON. THE RIDGE WILL WEAKEN  
AND ONSHORE FLOW WILL INCREASE FOR A BRIEF COOLING TREND MIDWEEK  
BEFORE WARMER CONDITIONS RETURN AS AN UPPER RIDGE REBUILDS.  
 

 
   
SHORT TERM /TONIGHT THROUGH TUESDAY/
 
THE CURRENT FORECAST  
REMAINS ON TRACK WITH NO PLANNED UPDATES. 33  
 
PREVIOUS DISCUSSION...THE WARMING TREND BEGINS SUNDAY AS FLOW  
ALOFT BECOMES MORE ZONAL. INTERIOR TEMPERATURES WILL CLIMB INTO  
THE MID TO UPPER 70S, WITH SOME LOCATIONS IN THE SOUTHWEST  
INTERIOR AND CASCADE VALLEYS REACHING AROUND 80°F. BY MONDAY, THE  
UPPER LEVEL RIDGE STRENGTHENS IN RESPONSE TO STRONG RIDGING OVER  
THE SOUTHWEST US, LEADING TO MORE WIDESPREAD 80S ACROSS INTERIOR  
AREAS, PARTICULARLY FROM SEATTLE SOUTHWARD. THE ECMWF AND GFS  
DETERMINISTIC MODELS, ALONG WITH THEIR RESPECTIVE ENSEMBLES, SHOW  
STRONG AGREEMENT ON THE CONTINUATION AND STRENGTHENING OF THE  
UPPER-LEVEL RIDGE THROUGH TUESDAY. THIS WILL RESULT IN THE WARMEST  
TEMPERATURES OF THE FORECAST PERIOD, WITH LOW TO MID-80S ACROSS  
MUCH OF THE PUGET SOUND REGION, AND SOME AREAS PUSHING INTO THE  
UPPER 80S. MODERATE HEATRISK COULD BE A CONCERN ON TUESDAY.  
   
LONG TERM /WEDNESDAY THROUGH SATURDAY/
 
ENSEMBLE GUIDANCE INDICATES  
A FLATTENING OF THE RIDGE AS A TROUGH CROSSES NORTHERN BRITISH  
COLUMBIA. THIS WILL PROMOTE INCREASING ONSHORE FLOW AND A  
COOLING TREND. THERE'S A SLIGHT CHANCE OF A SHOWER NEAR THE COAST  
OR NORTH CASCADES, BUT THE OVERALL FORECAST REMAINS DRY. UPPER  
RIDGING RETURNS LATE WEEK WITH TEMPERATURES RISING BACK ABOVE  
NORMAL.  
 

 
   
AVIATION
 
WESTERLY FLOW ALOFT CONTINUES WITH ONSHORE FLOW IN THE  
LOWER LEVELS AS AN UPPER LEVEL TROUGH MOVES EASTWARD. VFR CONDITIONS  
AT ALL OF THE TERMINALS THIS EVENING WITH SOME HIGH CLOUDS MOVING  
ACROSS THE AREA. MOST TERMINALS WILL REMAIN VFR FOR THE TAF PERIOD  
AS THE WESTWARD PUSH IS NOT EXPECTED TO BE AS STRONG AS 24 HOURS  
AGO. THAT SAID, WILL SEE MVFR CONDITIONS EMERGE OVERNIGHT ALONG THE  
COAST AND PERHAPS STRETCHING AS FAR EAST AS OLM. LATEST GUIDANCE  
KEEPS BOTH OLM AND CLM VFR, FURTHER LIMITING INLAND EXTENT.  
 
SURFACE WINDS REMAINING NORTHERLY FOR MOST TERMINALS WITH SPEEDS  
RANGING 8-12 KTS. EXCEPTIONS INCLUDE HQM AND CLM, BEING MORE EXPOSED  
TO THE DIRECT WESTERLY PUSH MENTIONED ABOVE...ALTHOUGH THEY WILL  
RETAIN SIMILAR SPEEDS. ANY MVFR CONDITIONS SHOULD SEE RECOVERY TO  
VFR LATE SUNDAY MORNING.  
 
KSEA...VFR CONDITIONS WILL CONTINUE THROUGHOUT THE TAF PERIOD.  
NORTHERLY WINDS GENERALLY 8 TO 12 KNOTS, DECREASING TO 5 KTS OR LESS  
BY 10-12Z. WIND SPEEDS PICK UP AGAIN BY NOON SUNDAY, RANGING 4-8  
KTS, WITH A DIRECTIONAL SHIFT TO MORE WESTERLY.  
 
MAZURKIEWICZ/18  
 

 
   
MARINE
 
SURFACE HIGH PRESSURE WILL CONTINUE TO REMAIN OFFSHORE  
THROUGHOUT THE WEEKEND AND INTO EARLY NEXT WEEK. DIURNAL WESTERLY  
PUSHES DOWN THE STRAIT WILL CONTINUE OVER THE NEXT SEVERAL  
EVENINGS, ESPECIALLY THIS EVENING AS A SMALL CRAFT ADVISORY  
REMAINS IN EFFECT. A WEAK SYSTEM MAY APPROACH THE AREA WATERS  
DURING THE MIDDLE OF THE WEEK WITH AN UPTICK IN WINDS AND SEAS.  
 
COMBINED SEAS LOOK TO HOVER BETWEEN 4 TO 6 FEET THROUGHOUT THE  
WEEKEND AND INTO THE EARLY HALF OF NEXT WEEK. SEAS MAY BECOME  
STEEP AT TIMES WITH CONTINUOUS NORTHERLY WINDS OVER THE WATERS.  
 
MAZURKIEWICZ  
 

 
   
SEW WATCHES/WARNINGS/ADVISORIES
 
 
WA...NONE.  
PZ...SMALL CRAFT ADVISORY UNTIL 3 AM PDT SUNDAY FOR CENTRAL U.S.  
WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S. WATERS  
STRAIT OF JUAN DE FUCA.  
 

 
 

 
 
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