419  
FXUS66 KSEW 102201  
AFDSEW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SEATTLE WA  
301 PM PDT THU JUL 10 2025  
   
SYNOPSIS
 
HIGH PRESSURE RETURNING TO THE REGION WILL RESULT IN  
AN EXTENDED PERIOD OF WARM AND DRY CONDITIONS THAT WILL PERSIST WELL  
INTO NEXT WEEK. TEMPERATURES ARE EXPECTED TO PEAK TUESDAY INTO  
WEDNESDAY, WHERE TEMPERATURES COULD REACH THE LOW TO MID 90S FOR  
MANY AREAS.  
 

 
   
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/
 
AS EXPECTED, THE  
DEEPER MARINE LAYER TODAY HAS HELPED THE STRATUS LINGER WELL  
INTO THE AFTERNOON. CEILINGS HAVE BEEN LIFTING AND STARTING TO  
SCATTER ALL ALONG THE I-5 CORRIDOR WITH SOME BLUE SKY LEADING  
INTO THE EVENING HOURS FOR MOST AREAS OUTSIDE OF THE COAST.  
HIGH TEMPERATURES ALONG THE COAST TODAY WILL REMAIN IN THE MID  
60S, WITH TEMPERATURES IN THE LOWER 70S THROUGH THE INLAND  
AREAS.  
 
THE OFFSHORE UPPER LEVEL RIDGE WILL TIP INTO THE PACIFIC  
NORTHWEST FRIDAY WITH LESS MORNING STRATUS AND A BUMP TO  
TEMPERATURES - BACK INTO THE LOWER TO MID 80S ACROSS MUCH OF  
THE INTERIOR LOWLANDS. LINGERING, ALBEIT WEAKER ONSHORE FLOW  
WILL MAINTAIN CLOUDY SKIES ALONG THE PACIFIC COAST WITH MOSTLY  
CLEAR AND DRY CONDITIONS ELSEWHERE. A WEAK UPPER LEVEL WAVE  
RIDING THE RIDGE SATURDAY WILL BRING A FEW EXTRA CLOUDS HIGH  
CLOUDS ESPECIALLY ALONG THE NORTHERN BORDER, BUT ULTIMATELY VERY  
SIMILAR CONDITIONS - WARM AND DRY WITH HIGHS IN THE 80S OVER THE  
INTERIOR AND NEAR 70 ALONG THE COAST.  
 

 
   
LONG TERM /SUNDAY THROUGH THURSDAY/
 
CONDITIONS ON SUNDAY INTO  
MONDAY LOOK TO BEGIN TRENDING WARMER AS HIGH PRESSURE CONTINUES  
TO BUILD OFFSHORE, WITH HIGH TEMPERATURES WORKING MORE INTO THE  
UPPER 80S. SOME OF THE ENSEMBLES DO SHOW PERHAPS A BIT OF A  
BRIEF PAUSE TO THE WARMING TREND MONDAY - WITH HIGHS STILL IN  
THE MID TO PERHAPS UPPER 80S. NBM CONTINUES TO HIGHLIGHT  
TEMPERATURES PEAKING TUESDAY INTO WEDNESDAY. FOR TUESDAY  
WIDESPREAD AREAS OVER THE INTERIOR SOUTH OF PUGET SOUND INTO  
THE CASCADE VALLEYS AND FOOTHILLS HAVING AN 80-85% CHANCE OF  
HIGH TEMPERATURES AT OR ABOVE 90. THIS WILL EXPAND WEDNESDAY -  
EXTENDING NORTHWARD THROUGH THE KITSAP PENINSULA, WESTERN KING  
AND SNOHOMISH COUNTIES. IN ADDITION TO THE VERY WARM DAYTIME  
TEMPERATURES, OVERNIGHT LOWS IN THE METRO AREA WILL START TO  
STRUGGLE TO COOL BELOW 60 DEGREES MONDAY NIGHT INTO TUESDAY  
MORNING. THIS WILL BROADEN TO MOST OF THE INTERIOR OVERNIGHT  
TUESDAY NIGHT AND AGAIN WEDNESDAY NIGHT. THE OVERALL WARMING  
TREND WILL RESULT IN WIDESPREAD MODERATE (ORANGE) HEATRISK TO  
WESTERN WASHINGTON BY TUESDAY WITH LOCAL AREAS OF MAJOR (RED)  
HEATRISK. SOME DEGREE OF COOLING IS NOW INDICATED FOR THURSDAY -  
BUT TEMPERATURES WILL LIKELY REMAIN IN THE 80S OVER MUCH OF THE  
INTERIOR - STILL WELL ABOVE NORMAL.  
 

 
   
AVIATION
 
FLOW TURNING NORTHWESTERLY THIS AFTERNOON AS AN UPPER-  
RIDGE BUILDS OFFSHORE. SHOWERS FROM EARLIER ARE DRYING OUT AND LOW  
STRATUS IS RISING AND GRADUALLY CLEARING AS A RESULT. MOSTLY VFR  
OBSERVED SO FAR BUT ISOLATED MVFR/IFR REMAINS (KHQM). FOR TONIGHT,  
STRATUS WILL BE MOSTLY CONFINED TO THE COAST, SW INTERIOR AND BITS  
HUGGING THE CASCADES. KHQM HAS A 70-80% CHANCE OF CIGS AROUND IFR TO  
LIFR OVERNIGHT INTO FRIDAY MORNING WITH MIST POSSIBLY LIMITING  
VISIBILITY. STRATUS WILL RETREAT TO THE IMMEDIATE COASTLINE BY 18Z  
FRIDAY WITH VFR FOR ALL INTERIOR TERMINALS EXPECTED. WINDS BECOMING  
NW THIS EVENING AND MAINTAIN A NORTHERLY COMPONENT INTO FRIDAY  
BETWEEN 5-10 KT (LIGHTER OVERNIGHT).  
 
KSEA...VFR NOW OBSERVED THIS AFTERNOON AND FAVORED TO REMAIN  
THROUGHOUT THE TAF PERIOD. THERE'S A 20% CHANCE OF MVFR CIGS  
BETWEEN 12-16Z FRIDAY DUE TO PATCHY MARINE STRATUS. SOUTHWEST  
WINDS TURNING NORTHWESTERLY BY 00Z FRIDAY WITH NW WINDS  
PERSISTING INTO THE DAY ON FRIDAY ON BETWEEN 5-10 KT.  
 
MCMILLIAN  
 

 
   
MARINE
 
FLOW TURNING NW OVER THE COASTAL WATERS THIS EVENING AS A  
SURFACE HIGH SITS WELL OFFSHORE. BENIGN SEAS TONIGHT BUT A SHALLOW  
MARINE LAYER COULD LEAD TO PATCHY FOG OVER AREA WATERS INTO FRIDAY  
MORNING. FOR FRIDAY, ONSHORE FLOW LOOKS TO INCREASE AND BECOME  
STRONG. SCA WINDS ARE PROBABLE FOR THE CENTRAL AND EASTERN STRAIT OF  
JUAN DE FUCA ON FRIDAY EVENING INTO EARLY SATURDAY MORNING. DIURNAL  
PUSHES ARE FAVORED THROUGHOUT THE STRAIT THIS WEEKEND AND COULD  
REACH ADVISORY LEVELS. A TROUGH PASSING TO THE NORTH EARLY NEXT WEEK  
MAY PRODUCE GUSTY WINDS IN THE OUTER COASTAL WATERS, ALONG WITH  
STEEPER SEAS.  
 
SEAS WILL RANGE 3-5 FEET TODAY THROUGH FRIDAY, INCREASING TO 6 TO 8  
FEET OVER THE WEEKEND, COUPLE SPOTS FURTHER OFFSHORE MAY SEE 10 FEET  
SEAS INTO EARLY NEXT WEEK.  
 
MCMILLIAN  
 

 
   
FIRE WEATHER
 
SKIES WILL BEGIN TO CLEAR OUT TONIGHT AS HIGH  
PRESSURE BEGINS TO BUILD OVER THE REGION, SIGNALING THE BEGINNING OF  
A PROLONGED WARMING AND DRYING TREND FROM FRIDAY THROUGH NEXT WEEK.  
FRIDAY WILL BE NOTABLY DRY, WITH RH VALUES DROPPING BACK INTO THE 25-  
35% RANGE OVER THE MOUNTAINS AS WELL AS THE INTERIOR LOWLANDS SOUTH  
OF THE PUGET SOUND. MORE ROBUST ONSHORE FLOW THIS WEEKEND WILL HELP  
USHER IN MORE MOIST AIR WITH MIN RHS BACK INTO THE 30S AND 40S,  
DESPITE HIGH TEMPERATURES REMAINING IN THE 80S.  
 
WHILE THERE IS STILL SOME MODEL DISCREPANCY OVER HOW WARM AND DRY WE  
GET NEXT WEEK, THERE IS CONSENSUS THAT THE WARM AND DRY WILL  
CONTINUE INTO THE MIDDLE OF NEXT WEEK, WITH THE FLOW SWITCHING TO  
OFFSHORE BY TUESDAY AS A THERMAL TROUGH BEGINS TO BUILD ALONG THE  
COAST. FIRE WEATHER CONCERNS WILL BE ELEVATED BEGINNING TUESDAY AS  
MINIMUM RH VALUES LOOK TO DROP INTO THE 20S ACROSS MUCH OF THE  
CASCADES AND THE INTERIOR LOWLANDS SOUTH OF SEATTLE. THERE MAY ALSO  
BE SOME LOCALLY BREEZY WINDS THROUGH THE CASCADE GAPS. THIS PATTER  
WILL CONTINUE TO BE CLOSELY MONITORED AS WE APPROACH NEXT.  
 
62  
 

 
 

 
   
SEW WATCHES/WARNINGS/ADVISORIES
 
 
WA...NONE.  
PZ...NONE.  
 

 
 

 
 
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