927  
FXUS66 KPQR 090440  
AFDPQR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PORTLAND OR  
940 PM PDT TUE JUL 8 2025  
   
UPDATE
 
QUICK UPDATE THIS EVENING. A STRONG SOUTHWEST TO  
WESTERLY MARINE PUSH IS UNDERWAY. THE KOTH-KPDX PRESSURE  
GRADIENT PEAKED AT OVER 7MB THIS EVENING, WHICH IS UP THERE.  
TYPICALLY, WHEN THIS GETS TO 5MB, WE ARE IN FOR A SOLID  
SOUTHWEST MARINE PUSH. GIVEN COAST RANGE GAP WINDS HAVE BEEN  
BLOWING 10-20 KT FOR MUCH OF THE EVENING AT KEUG, KCVO AND KMMV,  
MARINE AIR IS INFILTRATING THE WILLAMETTE VALLEY AND A  
SIGNIFICANT, ALBEIT SHORT LIVED CHANGE IS UNDERWAY. HAVE THE  
KEPT THE CURRENT SKY COVER AND TEMPERATURE FORECAST AS IS, BUT  
WOULD SUSPECT IT WILL BE SUBSTANTIALLY CLOUDIER IN THE MORNING  
THAN THE CURRENT DETERMINISTIC FORECAST SUGGESTS GIVEN THE  
OBSERVED PRESSURE GRADIENTS AND SURFACE WIND OBSERVATIONS. AS  
SUCH, WOULD ALSO EXPECT THAT THE CURRENT TEMPERATURE FORECAST IS  
TOO HIGH, POTENTIALLY BY QUITE A BIT DEPENDING ON HOW FAR AND  
QUICKLY MARINE CLOUDS PUSH INLAND OVERNIGHT. GIVEN THE TYPICALLY  
RELIABLE HREF GUIDANCE IS NOT BULLISH ON CLOUD COVER AND LITTLE  
MODEL GUIDANCE SUGGESTS A DRASTICALLY COOLER TEMPERATURE  
FORECAST, GOING TO FOREGO MAKING ANY DRASTIC CHANGES, WILL  
LEAVE THE GRIDS ALONE THIS EVENING AND LET THE NIGHT SHIFT  
MONITOR TRENDS AND ADJUST AS NECESSARY.  
 
IN ADDITION, SOME ELEVATED INSTABILITY AND LARGE SCALE LIFT  
AHEAD OF AN APPROACHING SHORTWAVE TROUGH TRIGGERED A LONE  
THUNDERSTORM OVER CLACKAMAS COUNTY THAT DIED QUICKLY AND IS NOW  
MOVING OVER THE WEST-CENTRAL COLUMBIA RIVER GORGE BEFORE IT WILL  
SHIFT NORTHEASTWARD TOWARDS MT ADAMS OVER THE NEXT 1-2 HOURS.  
CANNOT RULE OUT ANOTHER ISOLATED CELL, BUT OVERALL THIS THREAT  
SHOULD BE COMING TO AN END ACROSS OUR CWA WITH THE FOCUSING  
GENERALLY REMAINING EAST AND NORTHEAST OF OUR CWA OVERNIGHT.  
 
MEANWHILE, A WEAKENING COLD FRONT WILL PUSH INTO SOUTHWEST  
WASHINGTON AND NORTHWEST OREGON WEDNESDAY. NBM POPS HAVE COME  
DOWN A LITTLE BIT FROM EARLIER, WHICH GIVEN THE CURRENT  
LACKLUSTER AMOUNT OF RADAR RETURNS ACROSS THE OLYMPIC PENINSULA  
AND POINTS WEST DOES NOT SEEM UNREASONABLE. NONETHELESS, THESE  
SHALLOW FRONTS HAVE A TENDENCY TO OVERPERFORM AND WRING OUT A  
SURPRISING AMOUNT OF DRIZZLE SO WILL KEEP NBM POPS AS IS FOR  
WEDNESDAY MORNING. /NEUMAN  
 

 
   
SYNOPSIS
 
 
INLAND HIGHS AROUND 90 DEGREES AGAIN THIS AFTERNOON.  
A WEAK FRONTAL SYSTEM BRINGS MORE SEASONABLE TEMPERATURES FOR  
WEDNESDAY AND THURSDAY, WITH A CHANCE FOR SOME LIGHT RAIN ALONG  
NORTHERN COASTAL AREAS EARLY WEDNESDAY. HOTTER TEMPERATURES  
RETURN FRIDAY AND PERSIST INTO NEXT WEEK AS STRONG HIGH PRESSURE  
BUILDS OFFSHORE.  
 

 
   
SHORT TERM...NOW THROUGH THURSDAY NIGHT
 
 
NOW THROUGH THURSDAY NIGHT...HIGH PRESSURE REMAINS  
ENTRENCHED OVER THE WESTERN CONUS TODAY, PROMOTING CLEAR SKIES  
ACROSS ALL OF WESTERN OREGON AND WASHINGTON WITH THE EXCEPTION  
OF SOME PATCHY MARINE STRATUS ALONG THE IMMEDIATE COAST.  
OBSERVATIONS FROM AROUND THE AREA SHOW HIGHS IN THE UPPER 80S TO  
LOW 90S IN THE INTERIOR VALLEYS AS OF MID AFTERNOON. VISIBLE  
SATELLITE SHOWS CUMULUS FIELDS STARTING TO BECOME MORE AGITATED  
NEAR AND EAST OF THE CASCADE CREST IN CENTRAL OREGON, AND EXPECT  
THIS TO EVENTUALLY YIELD A FEW THUNDERSTORMS THIS AFTERNOON AND  
EVENING AS CUTOFF UPPER LEVEL LOW PRESSURE DRIFTS INLAND FROM  
NORTHERN CALIFORNIA. EXPECT MOST OF THIS ACTIVITY TO REMAIN ON  
THE EAST SIDE OF THE CASCADES, BUT WILL MAINTAIN A 15-20% CHANCE  
OF THUNDERSTORMS ALONG THE LANE COUNTY CASCADES THIS EVENING AS  
A FEW STORMS COULD MOVE NEAR THE CREST LATER TODAY.  
 
A BRIEF PATTERN CHANGE WILL COMMENCE TONIGHT AS A DEEP UPPER  
LEVEL TROUGH OVER THE GULF OF ALASKA PUSHES INLAND ACROSS  
WESTERN CANADA. THIS WILL SEND A WEAK SURFACE COLD FRONT ACROSS  
THE PACIFIC NORTHWEST EARLY WEDNESDAY, BRINGING ABOUT CLOUDIER  
WEATHER AND MORE SEASONABLE TEMPS FOR THE AREA WEDNESDAY INTO  
THURSDAY. EXPECT ANY PRECIPITATION CHANCES TO REMAIN LIMITED TO  
NORTHERN COASTAL AREAS AND PARTS OF SOUTHWEST WASHINGTON ON  
WEDNESDAY. MODEL QPF SUGGESTS PARTS OF PACIFIC COUNTY COULD SEE  
AS MUCH AS A TENTH OR TWO OF AN INCH OF RAIN THROUGH EARLY  
WEDNESDAY AFTERNOON, BUT OTHER LOCATIONS ALONG THE NORTH OREGON  
COAST OR THE COWLITZ VALLEY WILL LIKELY BE LIMITED TO A TRACE  
TO A FEW HUNDREDTHS. ALTHOUGH OTHER LOCATIONS ARE EXPECTED TO  
REMAIN DRY, PASSAGE OF THE FRONT WILL AT LEAST BRING SOME  
TEMPORARY RELIEF FROM THE RECENT HOT TEMPERATURES AS AFTERNOON  
HIGHS WILL RUN ABOUT 10 DEGREES COOLER IN THE INTERIOR VALLEYS,  
MAXING OUT IN THE UPPER 70S TO AROUND 80 DEGREES IN MOST  
LOCATIONS. EXPECT DRY WEATHER ON THURSDAY, WITH A BIT LESS CLOUD  
COVER AND TEMPERATURES REBOUNDING BY A FEW DEGREES INTO THE LOW  
80S IN MANY INTERIOR LOCATIONS. MEANWHILE, PERSISTENT ONSHORE  
FLOW AMD MARINE STRATUS WILL KEEP COASTAL TEMPERATURES IN THE  
LOW TO MID 60S GOING FORWARD. /CB  
   
LONG TERM...FRIDAY THROUGH TUESDAY
 
HOTTER TEMPERATURES RETURN  
ON FRIDAY AND LOOK TO PERSIST WELL INTO NEXT WEEK AS ENSEMBLE  
CLUSTERS REMAIN IN LOCK STEP IN DEPICTING A STRONG UPPER LEVEL  
RIDGE DEVELOPING ACROSS THE NE PACIFIC IN THE LONG TERM. THIS  
WILL LIKELY CORRESPOND TO A PROLONGED STRETCH OF DAYTIME HIGHS  
IN THE LOW 90S ACROSS THE WILLAMETTE VALLEY AND PORTLAND  
VANCOUVER METRO, HELPING TO MAINTAIN A MODERATE HEAT RISK IN  
THESE AREAS FROM FRIDAY INTO NEXT WEEK. THE PROBABILITY TO REACH  
95 DEGREES RANGES FROM 60-80% FROM SALEM TO EUGENE AND 25-40%  
IN THE PORTLAND/VANCOUVER METRO EACH DAY FROM FRIDAY THROUGH  
MONDAY. THE NBM IS HINTING AT THE POSSIBILITY FOR EVEN HOTTER  
TEMPERATURES NEXT TUESDAY AND WEDNESDAY, WITH NBM 75TH  
PERCENTILE GUIDANCE DEPICTING HIGHS REACHING THE LOW 100S FROM  
THE PORTLAND/VANCOUVER METRO TO EUGENE AND PUSHING HEAT RISK  
INTO THE MAJOR CATEGORY ON TUESDAY. IT SHOULD BE SAID THAT MORE  
MODEST HIGHS IN THE LOW 90S REMAIN WELL WITHIN THE RANGE OF  
OUTCOMES ON THESE DAYS, BUT THE POTENTIAL IS THERE FOR THE FIRST  
WIDESPREAD TRIPLE DIGIT READINGS OF THE SUMMER AS WE HEAD INTO  
TUESDAY AND THE MIDDLE OF NEXT WEEK.  
 
IN TERMS OF PRECIPITATION, CERTAINLY EXPECT MOST OF THE AREA TO  
REMAIN DRY THROUGH THE END OF THE LONG TERM. HOWEVER, DID NOTE  
THAT MOST DETERMINISTIC SOLUTIONS DEPICT A MID LEVEL IMPULSE OFF  
OF NORTHERN CALIFORNIA THIS WEEKEND AND EARLY NEXT WEEK, WHICH  
MAINTAINS AT LEAST A THOUGHT FOR A FEW THUNDERSTORMS IN THE  
VICINITY OF THE LANE COUNTY CASCADES INTO THE LONG TERM. MODEL  
PROBABILITIES ARE TOO LOW TO WARRANT INCLUSION OF THUNDERSTORMS  
IN THE FORECAST FOR NOW, BUT WILL NEED TO MONITOR THIS POTENTIAL  
AS MODELS START TO BETTER RESOLVE THIS FEATURE IN THE COMING  
DAYS. /CB  
 

 
   
AVIATION
 
WEAKENING HIGH PRESSURE OVER THE REGION WILL  
GIVE WAY TO A DYING FRONT SLIDING INTO NORTHWEST OREGON AND  
SOUTHWEST WASHINGTON WEDNESDAY MORNING. MARINE CLOUDS ARE  
PUSHING INTO THE COAST RANGE GAPS AS A STRONG SOUTHWEST TO WEST  
MARINE PUSH IS UNDERWAY WITH THE KOTH-KPDX GRADIENT PEAKING AT  
OVER 7MB EARLIER THIS EVENING. THIS SUGGESTS MARINE CLOUDS  
SHOULD DEEPEN SUBSTANTIALLY OVERNIGHT AND PUSH INTO THE  
WILLAMETTE VALLEY DESPITE MOST HIGH RESOLUTION MODEL GUIDANCE  
SUGGESTING OTHERWISE. AT THE MOMENT, HIGH RESOLUTION ENSEMBLE  
GUIDANCE SUGGESTS A 50% CHANCE THAT MARINE CLOUDS REACH KEUG AND  
STAY PRIMARILY DOWNRIVER OF KPDX & KTTD ALONG THE LOWEST  
STRETCHES OF THE COLUMBIA RIVER. GIVEN THE SOLID 10-20 KT SEA  
BREEZE OBSERVED MOST OF THE EVENING AT KEUG, KCVO, KS12 AND  
KMMV, AND THE AFOREMENTIONED OBSERVED PRESSURE GRADIENTS, HAVE  
HEDGED TOWARDS MVFR CEILINGS BEING MORE LIKELY THAN NOT WITH THE  
LATEST TAF PACKAGE FOR INLAND TAF SITES WEDNESDAY MORNING. THE  
AFOREMENTIONED DYING FRONT WILL PUSH ONTO OUR NORTHERN COASTAL  
ZONES AROUND DAYBREAK ON WEDNESDAY WITH A 50-60% CHANCE FOR  
DRIZZLE AND LIGHT RAIN AT KAST BETWEEN 12-20Z WEDNESDAY. THE  
ODDS THE FRONT HANGS ON ENOUGH TO PRODUCE MEASURABLE DRIZZLE OR  
LIGHT RAIN AND IMPACT VISIBILITIES FOR THE PORTLAND METRO TAF  
SITES HAS LOWERED TO ~10% AND DROPS TO WELL BELOW 10% AS ONE  
GOES SOUTHWARD IN THE WILLAMETTE VALLEY.  
 
PDX AND APPROACHES...WEAKENING HIGH PRESSURE OVER THE REGION WILL  
GIVE WAY TO A DYING FRONT SLIDING INTO NORTHWEST OREGON AND  
SOUTHWEST WASHINGTON WEDNESDAY. MARINE CLOUDS ARE PUSHING INTO  
THE COAST RANGE GAPS THIS EVENING AS A STRONG SOUTHWEST TO WEST  
MARINE PUSH IS UNDERWAY WITH THE KOTH-KPDX GRADIENT PEAKING AT  
OVER 7MB THIS EVENING. THIS SUGGESTS MARINE CLOUDS SHOULD  
DEEPEN SUBSTANTIALLY OVERNIGHT AND PUSH INTO THE WILLAMETTE  
VALLEY DESPITE MOST HIGH RESOLUTION MODEL GUIDANCE SUGGESTING  
OTHERWISE. GIVEN THE SOLID 10-20 KT SEA BREEZE OBSERVED MOST OF  
THE EVENING AT KEUG, KCVO, KS12 AND KMMV CURRENTLY, AND THE  
AFOREMENTIONED PRESSURE GRADIENT, HAVE HEDGED TOWARDS MVFR  
CEILINGS ARRIVING BETWEEN 12-15Z WEDNESDAY FOR THE PORTLAND TAF  
SITES. THE AFOREMENTIONED DYING FRONT WILL PUSH TOWARDS THE TAF  
SITES BETWEEN 15-20Z WEDNESDAY, BUT THE ODDS THE FRONT IS  
STRONG ENOUGH TO WRING OUT MEASURABLE DRIZZLE OR LIGHT RAIN AND  
IMPACT VISIBILITIES FOR THE PORTLAND METRO TAF SITES IS ~10%.  
/NEUMAN  
 

 
   
MARINE
 
A DENSE FOG ADVISORY HAS BEEN ISSUED TO ACCOUNT FOR THE  
FACT THAT THE WIDESPREAD LOW CLOUDS OVER THE WATERS ARE MOST  
LIKELY LOWERING TO THE OCEAN'S SURFACE IN THE VICINITY OF THE  
MAXIMUM UPWELLING, WHICH IS TYPICALLY WITHIN 20-30NM OF THE COAST.  
IN ADDITION, A WEAK FRONT IS CURRENTLY DROPPING SOUTHEASTWARD  
INTO THE WATERS. THIS WILL TURN THE WINDS SOUTHERLY ACROSS THE  
WATERS OVERNIGHT. WINDS WILL BE STRONGEST WITHIN 20 NM OF THE  
COAST, PARTICULARLY FROM CAPE FALCON NORTHWARD, BUT THERE IS A 75%  
CHANCE THAT SOUTHERLY WIND GUSTS REMAIN BELOW 20 KT. ONCE THE  
FRONT PASSES, WINDS WILL TURN WEST TO NORTHWESTERLY LATE IN THE  
DAY ON WEDNESDAY.  
 
WE WILL THEN RETURN A MORE TYPICAL NORTHERLY WIND PATTERN THURSDAY  
INTO FRIDAY AS HIGH PRESSURE BUILDS ACROSS THE NORTHEAST PACIFIC  
AND THERMALLY INDUCED LOWER PRESSURE RETURNS TO NORTHERN  
CALIFORNIA. THIS WILL PRODUCE GUSTY NORTHERLY WINDS AND CHOPPIER  
WIND DRIVEN SEAS, PARTICULARLY SOUTH OF CAPE FALCON. WINDS AND  
SEAS WILL BE STRONGEST OFF THE CENTRAL COAST OF OREGON AND WILL  
TYPICALLY PEAK IN THE AFTERNOON AND EVENING HOURS OVER THE INNER  
WATERS EACH DAY THROUGH THE WEEKEND. /NEUMAN  
 

 
   
PQR WATCHES/WARNINGS/ADVISORIES
 
 
OR...NONE.  
WA...NONE.  
PZ...DENSE FOG ADVISORY UNTIL 11 AM PDT WEDNESDAY FOR PZZ210-  
251>253-271>273.  

 
 

 
 
WWW.WEATHER.GOV/PORTLAND  
 
INTERACT WITH US VIA SOCIAL MEDIA:  
WWW.FACEBOOK.COM/NWSPORTLAND  
X.COM/NWSPORTLAND  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab OR Page
The Nexlab WA Page Main Text Page