584  
FXUS66 KPQR 071025  
AFDPQR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PORTLAND OR  
325 AM PDT MON JUL 7 2025  
   
SYNOPSIS
 
HIGH PRESSURE LINGERS THROUGH TUESDAY WITH A LOW  
SPINNING OVER NORTHERN CALIFORNIA ALOFT. TEMPERATURES WILL BE IN  
THE UPPER 80S TO LOW 90S THROUGH TUESDAY BUT WILL QUICKLY COOL  
ON WEDNESDAY AS THE LOW MOVES INLAND. SLIGHT CHANCE FOR SHOWERS  
ON WEDNESDAY IN SOUTHWEST WASHINGTON. WARMER TEMPERATURES RETURN  
LATE IN THE WEEK THOUGH CONFIDENCE IS QUITE LOW.  
 

 
   
SHORT TERM...NOW THROUGH WEDNESDAY NIGHT
 
HIGH PRESSURE  
CONTINUES TO BUILD OVER THE NORTHEAST PACIFIC WHICH WILL KEEP  
CONDITIONS DRY AND CAUSE TEMPERATURES TO RISE. SUNDAY HIGHS  
RANGED FROM THE MID 80S WITHIN THE WILLAMETTE VALLEY TO 60-70  
DEGREES F ALONG THE COAST, AND NEAR 80 DEG F WITHIN THE CASCADES  
AND FOOTHILLS. KEEP THESE TEMPERATURES IN MIND AS WE DIVE INTO  
TODAY'S FORECAST. THIS MORNING, LOW TEMPERATURES ARE AROUND 5 DEGREES  
WARMER THAN SUNDAY MORNING WHICH MEANS THAT WE ARE ALREADY  
STARTING WITH A LEG UP FOR EVEN WARMER TEMPERATURES TODAY.  
WHILE HIGHER RESOLUTION MODELS ARE TRENDING A LITTLE COOLER THAN  
THE NBM MEAN, THESE WARMER TEMPERATURES OVERNIGHT FURTHER SUPPORT  
THE WARMER DAYTIME TEMPERATURES OF THE NBM. STILL WILL SEE  
MODERATE HEATRISK FOR THE INLAND VALLEYS INCLUDING THE GORGE AND  
VALLEYS WITHIN THE CASCADE FOOTHILLS. WITH THE THERMAL TROUGH  
FORMING TO THE SOUTH, EXPECTING NORTHERLY WINDS ALONG THE COAST  
AND THE WILLAMETTE VALLEY. GUSTS UP TO 20 MPH ARE POSSIBLE. WILL  
NOTE THAT HUMIDITY WILL BE LOW (AROUND 25-30% RH) WITHIN THE  
WILLAMETTE VALLEY AND ALONG THE CASCADES.  
 
MINIMAL DIFFERENCE IN THE FORECAST FOR TUESDAY IN REGARDS TO  
TEMPERATURE AND IMPACTS. IN THE EVENING, THE RIDGE WILL BEGIN  
TO BREAK DOWN THOUGH AS A LOW ALOFT THAT IS SITTING NEAR  
NORTHERN CALIFORNIA BEGINS IT'S INLAND TREK. WINDS ALOFT WILL  
SHIFT TO THE NORTHWEST AND USHER IN A MOISTER AIRMASS. WINDS  
WILL BECOME GUSTY ALONG THE COAST RANGE RIDGETOPS, THE GAPS INTO  
THE WILLAMETTE VALLEY AND GORGE NEAR HOOD RIVER. THERE IS  
AROUND A 30% CHANCE OF GUSTS GREATER THAN 30 MPH IN THE UPPER  
HOOD RIVER VALLEY AND EXPOSED TERRAIN IN THE GORGE. WILL NOTE  
THAT AS THE LOW SHIFTS INLAND, THERE ARE A FEW SHORTWAVES  
FORMING IN THE MID-LEVEL FLOW. SOME WRAP AROUND MOISTURE IS  
POSSIBLE WITH THE INITIAL PASSAGE OF THE LOW, BUT CONFIDENCE IS  
VERY LOW ON WHETHER OR NOT PRECIPITATION IS POSSIBLE ALONG THE  
CASCADES. THE NBM IS SHOWING AROUND A 10% CHANCE OF VERY LIGHT  
SHOWERS OVER THE CASCADES TUESDAY NIGHT. HOWEVER, GIVEN THE  
PATTERN, SHOWERS SHOULD REMAIN EAST OF THE CASCADES.  
 
WEDNESDAY WILL SEE AN INCREASE IN THE ONSHORE FLOW AS A  
SHORTWAVE TROUGH DIGGING DOWN OVER WASHINGTON FROM THE NORTH,  
AND THE LOW THAT SAT OVER NORTHERN CALIFORNIA ADVECTS EASTWARD.  
THIS TROUGH BRINGS AROUND A 20-40% CHANCE OF LIGHT SHOWERS TO  
SOUTHWEST WASHINGTON WITH MOST OF NORTHWEST OREGON EVADING THE  
RAIN. TEMPERATURES WILL SWING AROUND 10 DEG F COOLER INLAND AS  
THE ONSHORE FLOW INCREASES. -MUESSLE  
 
   
LONG TERM...THURSDAY THROUGH SUNDAY
 
UNCERTAINTY INCREASES  
CONSIDERABLY IN THE LONG TERM FORECAST. GLOBAL ENSEMBLES ARE IN  
GOOD AGREEMENT IN A BROAD AREA OF HIGH PRESSURE FORMS OVER THE  
PACIFIC ON FRIDAY WITH A THERMAL TROUGH AT THE SURFACE. IN THIS  
SCENARIO, NORTH-EASTERLY WINDS WILL DOMINATE ALOFT WITH 850 MB  
TEMPERATURES AROUND 18 DEG C. THESE WARM TEMPERATURES WILL MIX  
DOWN TO THE SURFACE BRINGING SURFACE HIGHS TO SIMILAR VALUES TO  
WHAT IS EXPECTED MONDAY. WITH THE DRY AIR MOVING IN, WILL SEE  
DROPPING DAYTIME HUMIDITY AND GUSTY WINDS FROM THE NORTH.  
 
ON SATURDAY SOME OF THE GLOBAL MODELS ARE SUGGESTING ANOTHER  
SHORTWAVE TROUGH FORMING OVER THE OREGON/CALIFORNIA BORDER. THIS  
TROUGH COULD SHAKE UP THE FORECAST A BIT IF IT WERE TO  
MANIFEST. FOR EXAMPLE, LOOKING AT THE ENSEMBLE CLUSTERS, ONE  
ENSEMBLE CLUSTER IS SHOWING A DECREASE IN HEIGHTS FROM THE MEAN  
AND THUS, SUGGESTING TEMPERATURES WILL BE LOWER. ONSHORE FLOW  
IS FORECAST TO INCREASE ON SATURDAY AND SUNDAY THOUGH SO  
HUMIDITY SHOULD BE HIGHER, ESPECIALLY IN THE NORTHERN PORTIONS  
OF THE FORECAST AREA. OTHERS PATTERN OPTIONS THOUGH ARE  
CONTINUING A WARM PATTERN. THE PATTERN OVER THE WEEKEND IS  
CHAOTIC SO CONFIDENCE IS INCREDIBLY LOW. -MUESSLE  
 

 
   
AVIATION
 
VFR CONDITIONS AT ALL INLAND TERMINALS THROUGHOUT THE  
PERIOD, WITH A 40-70% CHANCE OF IFR CEILINGS OR LOWER AT COASTAL  
TERMINALS THROUGH 18Z MON DUE TO MARINE STRATUS. LIFR FOG MAY BE A  
POSSIBILITY AS WELL AT COASTAL TERMINALS, THOUGH THIS IS ONLY  
EXPECTED AT THE IMMEDIATE COAST. AFTER 18Z MON, COASTAL TERMINALS  
TRENDING TOWARDS VFR FOR THE REST OF DAYTIME HOURS (90%  
CONFIDENCE). WINDS PRESENTLY ARE FAIRLY WEAK, UNDER 5 KTS AT ALL  
TERMINALS AS OF 10Z MON. HOWEVER, DAYTIME HOURS WILL BRING DIURNAL  
HEATING BACK, AND NORTHERLY GUSTS UP TO 25 KTS AT THE COAST AND 20  
KTS INLAND ARE EXPECTED FROM 16-18Z MON ONWARDS, CONTINUING UNTIL  
5-7Z TUE.  
 
PDX AND APPROACHES...CLEAR SKY VFR CONDITIONS THROUGHOUT THE  
PERIOD. WINDS REMAIN UNDER 5 KTS FOR THE REST OF SUNDAY NIGHT, BUT  
INCREASE TO SEE NORTHERLY GUSTS UP TO 20 KT BETWEEN 18Z MON TO 5Z  
TUE. -JLIU  
 

 
   
MARINE
 
A TYPICAL SUMMERTIME PATTERN PERSISTS THROUGH MUCH OF  
THE COMING WEEK AS SURFACE HIGH PRESSURE OFFSHORE MAINTAINS NORTH  
TO NORTHWEST WINDS ACROSS THE COASTAL WATERS. RELATIVELY STRONG  
PRESSURE GRADIENT AT THE COAST DUE TO DIURNAL HEATING, AND  
ELEVATED WINDS REMAIN IN PLACE FOR ALL COASTAL WATERS THROUGH  
MONDAY NIGHT. SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH  
MONDAY EVENING AS WIND GUSTS INCREASE A BIT MORE TO 25 TO 30 KT  
MONDAY. EXPECT THE STRONGEST GUSTS SOUTH OF CAPE FALCON, WHILE  
CONDITIONS WILL BE MORE MARGINAL TO THE NORTH ACROSS THE MOUTH OF  
THE COLUMBIA RIVER AND THE SOUTH WASHINGTON COASTAL WATERS. SEAS  
WILL REMAIN IN THE 4-6 FT RANGE, COMPRISED MAINLY OF SHORT PERIOD  
WIND- DRIVEN WAVES AND A MODEST, MID-PERIOD WESTERLY SWELL.  
-CB/JLIU  
 

 
   
PQR WATCHES/WARNINGS/ADVISORIES
 
 
OR...NONE.  
WA...NONE.  
PZ...SMALL CRAFT ADVISORY UNTIL 10 PM PDT THIS EVENING FOR  
PZZ251>253-271>273.  

 
 

 
 
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