473  
FXUS66 KPQR 070327  
AFDPQR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PORTLAND OR  
825 PM PDT SUN JUL 6 2025  
   
SYNOPSIS
 
WEAK HIGH PRESSURE ALOFT WITH ONSHORE FLOW AT THE  
SURFACE. WARMING TEMPERATURES THROUGH TUESDAY WITH MODERATE  
HEATRISK IN THE INLAND LOWLANDS MONDAY AND TUESDAY. COOLER ON  
WEDNESDAY AND THURSDAY AS A BROAD LOW ALOFT MOVES NORTHWARD.  
FOR THE LATTER PART OF THE WEEK WARMING RETURN AS HIGH PRESSURE  
ALSO RETURNS.  
 

 
   
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
 
 
...EVENING FORECAST UPDATE FOR WINDS IN THE EUGENE AREA BEING ABOUT  
5-10 MPH STORNGER THAN FORECAST. THE NORTH WIND GRADIENT BETWEEN THE  
HIGH TO OUR NORTH AND LOW TO OUR SOUTH AND IN THE WILLAMETTE VALLEY  
HAD THINGS A LITTLE HIGHER THAN ANTICIPATED. NO ADDITIONAL UPDATES  
TO THE FORECAST. TF  
 
BROAD AREA OF HIGH PRESSURE BUILDS THROUGH THE START OF THE WEEK. AT  
THE SAME TIME, AN UPPER LEVEL LOW WILL PARK OVER NORTHERN CALIFORNIA  
THROUGH TUESDAY. WITH RIDGE OF HIGH PRESSURE POLE-WARD ALONG WITH AN  
UNDERCUTTING LOW, THIS CREATES A REX BLOCKING PATTERN. NOW, THIS  
BLOCKING PATTERN IS VERY WEAK, GIVEN THAT THE UPPER LEVEL RIDGE IS  
NOT VERY ROBUST. HOWEVER, THIS PATTERN WILL BRING ABOUT A WARMING  
AND DRYING TREND FOR THE FORECAST AREA THROUGH TUESDAY NIGHT.  
DAYTIME HIGHS AT THIS TIME ARE FORECASTED TO BE IN THE UPPER 80S TO  
LOW 90S FOR INLAND LOCATIONS AND INTO THE UPPER 60S TO LOW 70S ALONG  
THE COAST. HIGHEST TEMPERATURES ARE EXPECTED ON MONDAY. ON TUESDAY,  
THE UPPER LEVEL LOW THAT IS FORMING THE REX BLOCK, WILL START TO  
MEANDER NORTHWARD ALONG THE CALIFORNIA COAST. AS THAT UPPER LEVEL  
LOW MOVES NORTHWARD, THE GREAT BASIN SURFACE LOW WILL ALSO RESULT IN  
A TIGHTENING OF THE PRESSURE GRADIENT ALONG THE CASCADES AND COULD  
SEE GUSTS UP TO 30 MPH FOR THE CENTRAL AND EASTERN PARTS OF THE  
COLUMBIA RIVER GORGE ON TUESDAY.  
 
MONDAY AND TUESDAY WILL ALSO HAVE MODERATE HEATRISK FOR THE  
WILLAMETTE VALLEY, CLARK COUNTY LOWLANDS AND THE GORGE. THOSE  
SENSITIVE TO HEAT SHOULD TAKE PRECAUTIONS AND EVERYONE SHOULD  
REMAIN HYDRATED. /42  
   
LONG TERM...WEDNESDAY THROUGH SATURDAY
 
AS WEDNESDAY  
APPROACHES, THE REX BLOCK WILL CONTINUE TO BREAK DOWN AS BOTH  
THE UPPER LEVEL RIDGE BECOMES MORE ZONAL AND THE UPPER LEVEL LOW  
CONTINUES TO PUSH EASTWARDS TOWARDS EASTERN OREGON. THIS  
PATTERN CHANGE WILL ALSO BRING ABOUT RELATIVELY COOLER AND  
MOISTER AIR INTO THE REGION. 850 MB TEMPERATURES WILL DROP FROM  
16-18 DEG C ON TUESDAY TOWARD 8-10 DEG C ON WEDNESDAY AND  
THURSDAY. ONE NEWER FEATURE THAT HASN'T BEEN REALIZED YET IN  
PREVIOUS MODEL RUNS IS A WEAK MESO-LOW AND SHORTWAVE TROUGH AT  
THE MID-LEVELS FORMING OVER WASHINGTON. THE ADDED INSTABILITY  
COMBINED WITH MOISTER AIR AND COOLING TEMPERATURES IS BRINGING A  
SLIGHT CHANCE (LESS THAN 25%) OF VERY LIGHT PRECIPITATION TO  
SOUTHWEST WASHINGTON, AND LESS THAN A 10% CHANCE OF ISOLATED  
SHOWERS ALONG THE CENTRAL OREGON CASCADES. CONFIDENCE IS VERY  
LOW THOUGH AS THE PATTERN COULD EASILY SHIFT IF THE LOW TRACKS A  
BIT FURTHER NORTH. OVERALL, MOST PLACES SHOULD REMAIN DRY. WITH  
ALL THAT SAID, ANY PRECIPITATION THAT DOES FALL WILL BE LIGHT,  
BRIEF AND RESULT IN LITTLE TO NO ACCUMULATIONS.  
 
THURSDAY WILL BE DRY ONCE AGAIN WITH NEAR NORMAL HIGH  
TEMPERATURES IN THE 80S INLAND. AS THE LATTER PART OF THE WEEK  
AND THE WEEKEND APPROACHES, MODELS ARE SHOWING A BROAD, UPPER  
LEVEL RIDGE RETURNING TO THE EASTERN PACIFIC. SOME MODELS ARE  
ALSO SHOWING A MESO-LOW DEVELOPING AGAIN NEAR NORTHERN  
CALIFORNIA. EITHER OF THESE SCENARIOS LOOK TO BRING BACK A  
WARMING PATTERN FOR THE REGION AND COULD EASILY BE A REPEAT (OR  
VERY SIMILAR) OF MONDAY AND TUESDAY. AS A RESULT, DAYTIME HIGHS  
COULD WARM RIGHT BACK INTO THE UPPER 80S TO LOW 90S FOR INLAND  
LOCATIONS, WHILE THE COAST WARMS INTO THE 70S. THE FORECAST WILL  
CONTINUE TO EVOLVE THROUGH THE WEEK AND WILL LIKELY CHANGE AS  
DETAILS BECOME MORE CLEAR. /42  
 

 
   
AVIATION
 
HIGH PRESSURE CONTINUES TO BUILD OVER THE  
REGION TONIGHT LEADING TO CLEAR SKY VFR CONDITIONS ACROSS INLAND  
TERMINALS. SATELLITE IMAGERY AS OF 03Z MON SHOWS MARINE STRATUS  
FILLING IN ACROSS THE COASTAL WATERS. EXPECT THE STRATUS TO PUSH  
ONSHORE THIS EVENING AND REMAIN IN PLACE TONIGHT INTO MONDAY MORNING  
AS INCREASING SUBSIDENCE AND THE SHALLOW NATURE OF THE MARINE LAYER  
SUGGEST PROBABLE IFR TO LIFR CIGS WITH THE POTENTIAL FOR SOME  
PATCHES OF LIFR FOG ALONG THE CENTRAL COAST NEAR KONP, BREAKING OUT  
TOWARDS VFR AGAIN AFTER 18Z MON. OTHERWISE, VFR WILL PREVAIL THROUGH  
THE PERIOD AT THE INLAND TERMINALS. WINDS WILL DIMINISH BACK TO  
AROUND 5 KT AFTER 06Z MON, THEN CONTINUE TO FOLLOW A DIURNAL TREND,  
WITH N-NW WINDS INCREASING TO 10-15 KT WITH GUSTS TO 20-25 KT MONDAY  
AFTERNOON.  
 
PDX AND APPROACHES...VFR PREVAILS THROUGH THE PERIOD UNDER CLEAR  
SKIES. NW WINDS AROUND 10 KT WITH GUSTS UP TO 20 KT, EASING TO  
AROUND 5 KT AFTER 06-08Z MON. /DH  
 

 
   
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. INLAND HEATING WILL  
DRIVE A STRENGTHENING COASTAL PRESSURE GRADIENT THROUGH MONDAY,  
WHICH IS IN LINE WITH CURRENT OBSERVATIONS SHOWING GUSTS  
INCREASING TO 20-25 KT OVER THE WATERS. SMALL CRAFT ADVISORIES  
REMAIN IN EFFECT THROUGH MONDAY EVENING AS WIND GUSTS INCREASE A  
BIT MORE TO 25 TO 30 KT LATER TODAY INTO 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  
 

 
   
PQR WATCHES/WARNINGS/ADVISORIES
 
 
OR...NONE.  
WA...NONE.  
PZ...SMALL CRAFT ADVISORY UNTIL 10 PM PDT MONDAY FOR PZZ251>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