540  
FXUS66 KSEW 120940  
AFDSEW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SEATTLE WA  
240 AM PDT THU JUN 12 2025  
   
SYNOPSIS
 
A WEAK UPPER TROUGH WILL MOVE INTO WESTERN WASHINGTON  
TODAY THEN REMAIN OVER THE AREA ON FRIDAY. THIS WILL LEAD TO  
COOLER TEMPERATURES, INCREASED CLOUD COVER, AND OCCASIONAL CHANCES  
FOR MOUNTAIN SHOWERS AND COASTAL DRIZZLE. UPPER RIDGING WILL  
WEAKLY REBUILD LATE IN THE WEEKEND FOR A MODEST WARMING TREND  
BEFORE ANOTHER TROUGH APPROACHES THE AREA EARLY IN THE COMING  
WEEK.  
 

 
   
SHORT TERM /TODAY THROUGH SATURDAY/
 
A WEAK UPPER TROUGH WILL  
MOVE INTO WESTERN WASHINGTON LATE TODAY FOR A MOSTLY CLOUDY DAY  
AHEAD AND TEMPERATURES A LITTLE BELOW AVERAGE. THE TROUGH WILL  
LEAD TO A CHANCE OF SHOWERS ACROSS THE NORTH CASCADES AND NEAR THE  
CANADIAN BORDER TONIGHT AND FRIDAY AS A COUPLE OF WEAK DISTURBANCES  
PIVOT ACROSS THE REGION. OTHERWISE, MAINLY DRY CONDITIONS ARE  
EXPECTED.  
 
AN UPPER LEVEL TROUGH WILL START TO DIG SOUTHWARD OFFSHORE ON  
SATURDAY. THIS WILL LEAD TO A SLIGHT RISE IN HEIGHTS OVER WESTERN  
WASHINGTON. INTERIOR HIGH TEMPERATURES WILL EDGE CLOSER TO  
NORMAL, BUT CONTINUING ONSHORE FLOW WILL ENSURE THAT COASTAL AREAS  
WILL REMAIN MOSTLY CLOUDY AND ON THE COOL SIDE.  
   
LONG TERM /SUNDAY THROUGH WEDNESDAY/
 
THE PATTERN REMAINS RATHER  
STATIC HEADING INTO SUNDAY WITH AN UPPER TROUGH OFFSHORE AND WEAK  
RIDGING OVER WESTERN WASHINGTON. MODEL AGREEMENT IS STARTING TO  
FALL INTO PLACE EARLY NEXT WEEK MORE SO THAN THE PAST FEW NIGHTS.  
A WEAK UPPER TROUGH IS SLATED TO MOVE ONSHORE ON MONDAY, BUT WILL  
PROBABLY PRODUCE LITTLE MORE THAN A BUMP IN ONSHORE FLOW AND THE  
ASSOCIATED SLIGHT COOLING THAT COMES WITH IT. A MAJORITY OF THE ENSEMBLES  
FROM BOTH THE GFS AND EURO ARE NOW TARGETING THE TUESDAY/WEDNESDAY  
PERIOD FOR A SOMEWHAT MORE SUBSTANTIAL UPPER TROUGH (BY MID JUNE  
STANDARDS) TO MOVE INTO THE REGION AND PRODUCE SOME LIGHT PRECIP.  
IT'S NOT SHAPING UP TO PRODUCE MUCH IN THE WAY OF IMPACTS, BUT IT  
COULD BE THE BEGINNING OF A MORE PROLONGED PERIOD OF COOLER, MORE  
UNSETTLED CONDITIONS THAT WILL SHARPLY CONTRAST HOW THE MONTH  
BEGAN. 27  
 

 
   
AVIATION
 
UPPER LEVEL TROUGH MOVING THROUGH THE AREA TODAY.  
SOUTHWESTERLY FLOW ALOFT BECOMING WESTERLY BEHIND THE TROUGH  
TONIGHT. LOW LEVEL ONSHORE FLOW THROUGH FRIDAY.  
 
MVFR CEILINGS OVER PARTS OF THE AREA EARLY THIS MORNING. STRATUS  
WILL FILL IN WITH MVFR CEILING OVER THE ENTIRE AREA BY 14Z.  
ISOLATED IFR CEILINGS AT THE HIGHER AIRPORTS. STRATUS LIFTING LATE  
MORNING WITH THE STRATUS DISSIPATING OVER THE INTERIOR 19Z-21Z.  
MVFR CEILINGS CONTINUING ALONG THE COAST. STRATUS MOVING BACK  
INLAND TONIGHT RETURNING TO THE PUGET SOUND AREA 09Z-12Z.  
 
KSEA...MVFR CEILINGS THROUGH THE MORNING. STRATUS DISSIPATING  
19-20Z. VFR CEILINGS THIS AFTERNOON INTO THE EARLY MORNING HOURS.  
STRATUS RETURNING TO THE TERMINAL AROUND 10Z WITH MVFR CEILINGS.  
SOUTHWEST WIND 8 TO 12 KNOTS BECOMING WEST NORTHWESTERLY 4 TO 8  
KNOTS AROUND 01Z. WINDS BECOMING SOUTHWESTERLY AGAIN AROUND 06Z.  
FELTON  
 

 
   
MARINE
 
SURFACE HIGH PRESSURE CENTERED OFFSHORE THROUGH THE END  
OF THE WEEK WILL MOVE CLOSER TO THE COASTAL WATERS OVER THE  
WEEKEND. A WEAKENING FRONT WILL REACH THE WATERS MONDAY NIGHT.  
 
SMALL CRAFT ADVISORY WESTERLY WINDS LINGERING IN THE CENTRAL AND  
EASTERN STRAIT OF JUAN DE FUCA THIS MORNING. WINDS EASING LATE  
MORNING THEN INCREASING AGAIN THIS EVENING BACK UP TO SMALL CRAFT  
ADVISORY SPEEDS ( 20 TO 25 KNOTS ). DIURNAL WESTERLY PUSHES THROUGH  
STRAIT OF JUAN DE FUCA ARE EXPECTED THROUGH THE WEEKEND WITH  
POSSIBLE SMALL CRAFT ADVISORY WINDS EACH EVENING FRIDAY THROUGH  
SUNDAY.  
 
SMALL CRAFT ADVISORIES CONTINUE FOR THE OUTER COASTAL WATERS DUE  
TO SEAS REMAINING GENERALLY AROUND 8 FEET WITH DOMINANT PERIODS  
AROUND 8 SECONDS THROUGH AT LEAST FRIDAY. WITH THE PERSISTENT  
NORTHWESTERLY WINDS, EXPECT SEAS TO REMAIN CHOPPY OVER THE OUTER  
COASTAL WATERS THROUGH THE WEEKEND. NORTHWESTERLY WINDS GENERALLY  
20 KNOTS OR LESS WITH THE EXCEPTION OF A ROUND OF 25 KNOT WINDS IN  
THE NORTHERN OUTER WATERS TONIGHT INTO FRIDAY MORNING. FELTON  
 

 
   
SEW WATCHES/WARNINGS/ADVISORIES
 
 
WA...NONE.  
PZ...SMALL CRAFT ADVISORY UNTIL 9 AM PDT THIS MORNING FOR CENTRAL  
U.S. WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S.  
WATERS STRAIT OF JUAN DE FUCA.  
 
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM PDT FRIDAY  
FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST  
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.  
 
SMALL CRAFT ADVISORY UNTIL 6 PM PDT FRIDAY FOR COASTAL WATERS  
FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL  
WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-  
COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10  
TO 60 NM.  
 

 
 
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