438  
FXUS66 KSEW 021605  
AFDSEW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SEATTLE WA  
905 AM PDT THU OCT 2 2025  
   
SYNOPSIS
 
AN UPPER LEVEL LOW WILL SINK SOUTHWARD TODAY, WRAPPING  
MOISTURE INTO WESTERN WASHINGTON AS IT DOES SO. THIS WILL KEEP THE  
CHANCE FOR SHOWERS OVER THE AREA. DRY CONDITIONS EXPECTED TO EMERGE  
TONIGHT. ALTHOUGH GENERALLY DRY CONDITIONS ARE EXPECTED FOR THE  
REMAINDER OF THE FORECAST DUE TO HIGH PRESSURE ALOFT, SOME WEAK  
DISTURBANCES MAY ALLOW FOR A CHANCE FOR SHOWERS THIS WEEKEND.  
 

 
   
SHORT TERM /TODAY THROUGH SATURDAY/
 
THE UPPER LEVEL LOW CONTINUES  
TO CHURN OUT OVER THE PACIFIC, BRINGING IN ANOTHER WAVE OF SHOWERS  
TO THE AREA AS PER CURRENT RADAR. MOST ACTIVITY IS FOCUSED ON THE  
OLYMPIC PENINSULA AND MOVING NORTH-NORTHEASTWARD, SO DIFFICULT TO  
SAY HOW MUCH OF AN IMPACT THIS MIGHT HAVE ON LOCATIONS EAST OF THE  
SOUND, INCLUDING THE SEATTLE METRO AREA. EVER SINCE THE SUN WENT  
DOWN LAST NIGHT, NO LIGHTNING HAS BEEN DETECTED WITH THIS PRECIP AND  
AS SUCH WILL LIKELY RELY ON DAYTIME HEATING TO INTRODUCE THE ENERGY  
NECESSARY FOR CONVECTION. THAT SAID, MODELS DO SHOW SOME  
INSTABILITY, BUT IT IS PRIMARILY FOCUSED ON THE COASTAL WATERS AND  
THE IMMEDIATE COASTAL AREA. GIVEN THE STRONGEST ACTIVITY SEEMED TO  
BE FOCUSED THERE YESTERDAY, SEEMS LIKE A GOOD FIT FOR ISOLATED  
THUNDERSTORMS TO BE A PROSPECT THERE THIS AFTERNOON AND EARLY  
EVENING.  
 
THE UPPER LOW WASTES NO TIME PLUNGING TO THE SOUTH BY THIS EVENING,  
TAKING THE MAJORITY OF ITS ASSOCIATED MOISTURE WITH IT. THIS SHOULD  
RESULT IN DRY CONDITIONS OVER W WA AS EARLY AS THIS EVENING,  
ALTHOUGH MOST LIKELY OVERNIGHT TONIGHT. MODELS REMAIN ON TRACK FOR A  
STRONG UPPER LEVEL RIDGE TO BUILD OVER THE PACIFIC, BECOMING THE  
MAIN INFLUENCE TO W WA WEATHER FOR THE REMAINDER OF THE SHORT TERM.  
AS THE RIDGE STRENGTHENS, TEMPERATURES WILL REMAIN MILD AND  
SEASONABLE...HOWEVER THERE IS SOME CONSISTENCY IN ADVERTISING A  
COUPLE OF WEAK DISTURBANCES ON THE LEADING EDGE OF THIS RIDGE. THIS  
COULD RESULT IN SLIGHT CHANCE TO CHANCE POPS OVER THE AREA AT TIMES  
FRIDAY EVENING INTO SATURDAY, BUT PROBABILITIES REMAIN LOW ENOUGH TO  
ADD SOME CONFIDENCE TO A GENERALLY DRY CLOSE TO THE SHORT TERM.  
 
18  
   
LONG TERM /SUNDAY THROUGH WEDNESDAY/
 
THE UPPER LEVEL RIDGE  
REMAINS THE MAIN WEATHER FEATURE FOR THE LONG TERM PORTION OF THE  
FORECAST AS ITS AXIS GRADUALLY SHIFTS EASTWARD THROUGHOUT THE  
PERIOD. THIS LOOKS TO ENSURE DRY CONDITIONS FOR THE FIRST HALF OF  
NEXT WEEK. THIS FEATURE WILL INITIATE A WARMING TREND, BRINGING A  
RETURN TO DAYTIME HIGHS IN THE LOWER 70S IN THE INTERIOR LOWLANDS  
MONDAY AND TUESDAY. SOME ENSEMBLE MEMBERS HINTING AT AN UPPER LEVEL  
TROUGH SINKING DOWN TOWARD THE AREA LATE TUESDAY INTO WEDNESDAY,  
PUSHING THE RIDGE AXIS BACK WESTWARD AND OUT TO SEA. WHILE THIS  
COULD REINTRODUCE RAIN TO THE FORECAST, GIVEN HOW FAR OUT THIS WOULD  
OCCUR ALONG WITH THIS BEING A RELATIVELY NEW-ISH SOLUTION, NOT MUCH  
CONFIDENCE AT THIS TIME. AS SUCH, THE LOW POPS PROVIDED BY THE NBM  
IS IN LINE WITH CURRENT THINKING UNTIL THIS SOLUTION BECOMES EITHER  
MORE CONSISTENT, INCLUDES MORE MEMBERS OR BOTH.  
 
18  
 

 
   
AVIATION
 
SOUTHWEST FLOW ALOFT WILL CONTINUE THROUGH TODAY BEFORE  
BECOMING LIGHT TONIGHT AS AN UPPER LOW WEAKENS AND MOVES ACROSS  
WESTERN WASHINGTON. VFR CONDITIONS FOR THE MAJORITY OF TERMINALS  
THIS MORNING WITH AREAS OF MVFR/IFR CIGS ALONG THE COAST WITH  
CONTINUED SHOWERS. VFR CONDITIONS ARE EXPECTED THIS AFTERNOON WITH  
RAIN SHOWERS LINGERING, MAINLY ALONG THE OLYMPIC PENINSULA. LOW  
STRATUS MAY DEVELOP LATER TONIGHT INTO FRIDAY MORNING, ALONG WITH  
POTENTIAL FOR FOG DEVELOPMENT, ESPECIALLY IN PRONE AREAS DUE TO  
RESIDUAL MOISTURE AND LIGHT WINDS. SOUTH WINDS THROUGH THIS  
AFTERNOON WILL BECOME LIGHT TONIGHT.  
 
KSEA...VFR CONDITIONS INTO TONIGHT WITH MID AND HIGH CLOUDS. A FEW  
RAIN SHOWERS MAY BE AROUND PUGET SOUND THIS AFTERNOON, BUT  
PREDOMINANTLY DRY CONDITIONS ARE EXPECTED AT THE TERMINAL. LOW  
STRATUS OR FOG DEVELOPMENT MAY OCCUR FRIDAY MORNING, BUT CONFIDENCE  
REMAINS LOW IN LOCATION AT THIS TIME. CURRENT PROBABILITIES FOR  
IFR/LIFR CIGS ARE 25% AND 20% RESPECTIVELY BETWEEN 13 AND 18Z  
FRIDAY. OTHERWISE, S/SW SURFACE WINDS MAY BECOME VRB FOR A BRIEF  
PERIOD THIS EVENING (MAINLY BETWEEN 02-06Z). JD  
 

 
   
MARINE
 
GALE FORCE SOUTHERLY WINDS WILL START TO DECREASE IN  
STRENGTH LATER THIS MORNING AS A WEATHER SYSTEM STARTS TO WEAKEN  
OFFSHORE. WINDS WILL LOWER TO SMALL CRAFT STRENGTH, THEREFORE  
HAVE CONTINUED THE SMALL CRAFT ADVISORIES FOR THE COASTAL WATERS,  
EASTERN ENTRANCE OF THE STRAIT, AND THE NORTHERN INTERIOR WATERS  
UNTIL THIS AFTERNOON. WINDS WILL CONTINUE TO BECOME LIGHT HEADING  
INTO FRIDAY, ALONG WITH WINDS TAKING A MORE NORTHERLY DIRECTION  
INTO THE WEEKEND.  
 
THERE REMAINS A 15-20% CHANCE OF THUNDERSTORMS OVER THE COASTAL  
WATERS THIS AFTERNOON. CONVECTIVE SHOWERS OR THUNDERSTORMS MAY BE  
ACCOMPANIED BY BRIEF ERRATIC WINDS AND SMALL HAIL. THE  
THUNDERSTORM THREAT OVER THE COASTAL WATERS WILL DIMINISH BY THE  
EVENING HOURS.  
 
COMBINED SEAS THIS MORNING OF 15 TO 18 FEET. SEAS WILL SUBSIDE  
LATER THIS MORNING 13 TO 15 FEET, AND FURTHER LOWERING BELOW 10  
FEET BY THIS EVENING. SEAS WILL LOWER TO 4 TO 6 FEET BY FRIDAY  
MORNING AND MAINTAIN THAT HEIGHT OVER THE WEEKEND.  
 
MAZURKIEWICZ  
 

 
   
SEW WATCHES/WARNINGS/ADVISORIES
 
 
WA...NONE.  
PZ...SMALL CRAFT ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR COASTAL  
WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-  
COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-  
COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO  
60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE  
OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE  
SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE  
TO CAPE SHOALWATER OUT 10 NM-GRAYS HARBOR BAR.  
 
SMALL CRAFT ADVISORY UNTIL 2 PM PDT THIS AFTERNOON FOR EAST  
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-NORTHERN INLAND  
WATERS INCLUDING THE SAN JUAN ISLANDS.  
 

 
 

 
 
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