610  
FXUS66 KPQR 021726 AAA  
AFDPQR  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE PORTLAND OR  
1026 AM PDT SAT MAY 2 2026  
 
UPDATED AVIATION DISCUSSION  
   
SYNOPSIS
 
BROAD HIGH PRESSURE OVER THE REGION WILL MAINTAIN  
GENERALLY DRY CONDITIONS THROUGH THE NEXT SEVERAL DAYS. AN UPPER  
LEVEL LOW OFFSHORE WILL BRING CHANCES FOR ELEVATED  
THUNDERSTORMS OVER THE CASCADES TODAY, HOWEVER, SOME OF WHICH  
MAY TRACK TOWARD THE WILLAMETTE VALLEY THIS AFTERNOON AND  
EVENING. A WARMING TREND WILL PEAK ON SUNDAY WITH DAILY RECORD  
HIGH TEMPERATURES IN THE FORECAST FOR SOME INLAND AREAS.  
TEMPERATURES WILL COOL BUT REMAIN ABOVE NORMAL INTO THE NEXT  
WORKWEEK.  
 

 
   
SHORT TERM...NOW THROUGH SUNDAY NIGHT
 
AN ELONGATED UPPER  
TROUGH JUST OFFSHORE OF THE WASHINGTON AND OREGON COASTS  
CONTINUES TO PINCH OFF INTO A CLOSED LOW THAT WILL DRIFT  
SOUTHWARD TOWARD THE CALIFORNIA COAST THROUGH THE REMAINDER OF  
THE WEEKEND WHILE A BROAD UPPER-LEVEL RIDGE OTHERWISE PERSISTS  
OVER THE NORTHEAST PACIFIC AND WESTERN CONUS. NORTHERLY SURFACE  
FLOW CONTINUES ACROSS THE REGION WITH COASTAL MARINE STRATUS  
EXPECTED TO DIMINISH IN COVERAGE THROUGH TODAY, BUT LESS SO IN  
COASTAL PORTIONS OF LANE AND LINCOLN COUNTIES.  
 
SUFFICIENT VORTICITY ADVECTION ALOFT ON THE EASTERN FLANK OF THE  
DEVELOPING CLOSED LOW WILL SUPPORT ANOTHER ROUND OF AFTERNOON  
AND EVENING CONVECTION LATER TODAY. THERE CONTINUES TO BE HIGH  
CONFIDENCE IN SURFACE-BASED INSTABILITY REACHING 1000-1500 J/KG  
OR MORE ON THE WEST SIDE OF THE CASCADE CREST BY THE EARLY  
AFTERNOON, WHILE THE SOUTHERLY MID-LEVEL STEERING FLOW IN PLACE  
EARLY THIS MORNING WILL BACK OUT OF THE SOUTHEAST THROUGH THIS  
AFTERNOON. ANY CONVECTION THAT DOES DEVELOP ON THE WESTERN  
SLOPES OF THE CASCADES MAY THEREFORE TEND TO MOVE TOWARD THE  
WILLAMETTE VALLEY, AND CAMS CONTINUE TO SUPPORT MODEST CHANCES  
(15-35%) FOR THUNDERSTORMS BETWEEN I-5 AND THE CASCADE CREST.  
THESE CHANCES ARE HIGHEST CLOSER TO THE UPPER LOW, NAMELY OVER  
LANE, LINN, AND MARION COUNTIES, BUT AN ISOLATED THUNDERSTORM AS  
FAR NORTH AS THE COLUMBIA RIVER AND PORTLAND/VANCOUVER METRO  
CERTAINLY CANNOT BE RULED OUT. THAT ALL BEING SAID, SHEAR WILL  
LIKELY REMAIN TOO LOW AND SEVERE STORMS ARE NOT ANTICIPATED.  
THE MOST LIKELY TIME FOR THUNDER WILL BE FROM 2-8 PM TODAY.  
 
AS THE UPPER LOW DRIFTS FARTHER SOUTH OFF OF CALIFORNIA THROUGH  
TONIGHT, RENEWED UPPER RIDGING WILL COME TO AGAIN DOMINATE  
CONDITIONS LOCALLY. INCIPIENT OFFSHORE FLOW WILL MAINTAIN MILD  
OVERNIGHT TEMPERATURES IN THE 50S, WITH THE COLUMBIA RIVER GORGE  
AND PORTLAND/VANCOUVER METRO POSSIBLY (NEAR 50% AND 20-35%  
CHANCE, RESPECTIVELY) FAILING TO FALL BELOW 60F TONIGHT INTO  
EARLY SUNDAY MORNING. AS MID-LEVEL TEMPERATURES RISE TO 17-18C  
BY SUNDAY AFTERNOON, DEEP MIXING WILL PUSH SURFACE TEMPERATURES  
SOME 15-25F ABOVE NORMAL FOR EARLY MAY. CHANCES TO EXCEED 90F  
REMAIN THE HIGHEST, 75-95% CHANCE, IN THE PORTLAND/VANCOUVER  
METRO, WITH LOWER BUT STILL NOTABLE CHANCES ELSEWHERE: NEAR 40%  
IN THE COWLITZ/LEWIS VALLEYS INCLUDING KELSO/LONGVIEW, 30-50% IN  
THE NORTHERN WILLAMETTE VALLEY FROM SALEM NORTHWARD, AND 10-30%  
ELSEWHERE AT LOW ELEVATIONS INLAND, INCLUDING EUGENE/SPRINGFIELD  
AND ALBANY/CORVALLIS. VALLEYS WITHIN THE WESTERN CASCADE AND  
EASTERN COAST RANGE SLOPES WILL ALSO SEE 25-50% CHANCES OF  
HITTING 90F SUNDAY AFTERNOON. WARMER THAN NORMAL TEMPERATURES  
WILL EXTEND NEARLY ALL THE WAY WEST TO THE COAST, WITH IMMEDIATE  
COASTAL LOCALES REMAINING CLOSER TO SEASONAL NORMS. WHILE  
OFFSHORE FLOW WEAKENS ON SUNDAY NIGHT, ANOTHER MILD NIGHT IN THE  
50S WILL STILL PROVIDE RELIEF FROM THE HEAT, ALTHOUGH THERE  
CONTINUE TO BE 25-50% CHANCES TEMPERATURES REMAIN ABOVE 60F  
THROUGH EARLY MONDAY MORNING ALONG THE I-5 AND I-84 CORRIDORS  
NORTH AND EAST OF THE PORTLAND/VANCOUVER METRO.  
 
THESE FORECAST HIGH TEMPERATURES REMAIN ON TRACK TO CHALLENGE  
DAILY RECORDS AT INLAND CLIMATE SITES ALONG THE I-5 CORRIDOR ON  
SUNDAY; REFER TO THE CLIMATE SECTION BELOW FOR DETAILS ON  
CURRENT RECORD VALUES ACROSS THE REGION. THE COMBINATION OF MILD  
NIGHTS AND A HOT AFTERNOON CONTINUE TO YIELD MODERATE HEATRISK  
ACROSS THE PORTLAND/VANCOUVER METRO AND LOWER COLUMBIA & COWLITZ  
VALLEYS, AND A HEAT ADVISORY THEREFORE REMAINS IN EFFECT FOR  
THESE AREAS FROM 9 AM THROUGH 11 PM SUNDAY. THOSE SENSITIVE TO  
HEAT OR PARTICIPATING IN STRENUOUS OUTDOOR ACTIVITIES MAY BE AT  
HIGHER RISK OF DEVELOPING HEAT ILLNESS, AND SHOULD DRINK PLENTY  
OF FLUIDS OR FIND A COOL PLACE TO AVOID THE PEAK AFTERNOON HEAT.  
DESPITE HOT AIR TEMPERATURES, AREA RIVERS AND LAKES REMAIN COLD  
ENOUGH TO CAUSE COLD SHOCK AND POSSIBLE DEATH. THOSE HEADING TO  
THE COAST TO AVOID THE HEAT SHOULD REMAIN AWARE OF AN ELEVATED  
RISK FOR SNEAKER WAVES THROUGH SUNDAY. SNEAKER WAVES CAN SWEEP  
YOU OFF OF YOUR FEET AND DISLODGE LOGS CAUSING HAZARDOUS  
CONDITIONS. AVOID JETTIES, ROCKS, AND LOGS WITHIN THE SURF  
ZONE, AND NEVER TURN YOUR BACK ON THE OCEAN. -36  
   
LONG TERM...MONDAY THROUGH FRIDAY
 
BY THE BEGINNING OF THE  
WORKWEEK, ENSEMBLE GUIDANCE CONTINUES TO FAVOR MODERATING  
TEMPERATURES AS THE UPPER RIDGE AXIS MOVES INLAND. A SOUTHERLY  
WIND REVERSAL WILL INCREASE MARINE STRATUS COVERAGE ALONG THE  
COAST, WITH BROADER ONSHORE FLOW COOLING INLAND AREAS AS WELL.  
THERE IS GENERAL CONSENSUS IN DRY CONDITIONS ACROSS MOST OF THE  
REGION, HOWEVER A MINORITY OF ENSEMBLE MEMBERS DEPICT VERY LIGHT  
RAIN OR DRIZZLE WITHIN THE SHALLOW MARINE LAYER, MOST LIKELY IN  
THE OVERNIGHT OR EARLY MORNING HOURS.  
 
LATE IN THE WEEK, GUIDANCE FAVORS A FLATTENING OF THE UPPER  
RIDGE AS SHORTWAVE IMPULSES RIDE UP AND OVER ITS NORTHERN  
PERIPHERY. THIS PATTERN WILL FAVOR TEMPERATURES COOLING FURTHER  
TOWARD SEASONAL NORMS, AS WELL AS SUPPORTING LOW (10-25%)  
CHANCES FOR LIGHT RAIN ACROSS PORTIONS OF THE REGION. -36  
 

 
   
AVIATION
 
GENERALLY MVFR CONDITIONS EXPECTED TO IMPROVE TOWARDS  
A VFR/MVFR MIXTURE THROUGH 20Z SATURDAY ALONG WITH AN INCREASING  
PROBABILITY FOR SHOWERS AND THUNDERSTORMS FOR INLAND LOCATIONS.  
 
AFTER 20Z SATURDAY, CHANCES FOR SHOWERS INCREASE ALONG WITH A  
15-35% CHANCE FOR THUNDERSTORMS DEVELOPING ON THE WEST SIDE OF  
THE CASCADE CREST. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO TRACK  
FROM THE SOUTH/SOUTHEAST TO THE NORTHWEST. WHICH DOES BRING A  
THREAT OF THUNDERSTORMS TO MOST INLAND LOCATIONS. AT THIS TIME THE  
CHANCE FOR THUNDERSTORMS IS 15-25%, WITH A START TIME FOR INCREASED  
SHOWERS AND THUNDERSTORMS STARTING AROUND 00Z SUNDAY. ANY SHOWERS  
OR THUNDERSTORMS WILL TEND TO DISSIPATE AFTER 03Z SUNDAY.  
 
NORTH TO NORTHWESTERLY WINDS AT 5-10 KT WILL CONTINUE THROUGH  
03Z-06Z SUNDAY, WHEN OFFSHORE NORTHEASTERLY FLOW WILL BEGIN TO  
DEVELOP. AS SHOWERS AND THUNDERSTORMS MOVE OUT OF THE AREA  
AFTER 06Z SUNDAY, EXPECT IFR/LIFR CONDITIONS TO RETURN TO COAST  
LOCATIONS.  
 
KPDX AND APPROACHES...GENERALLY MVFR CONDITIONS EXPECTED TO  
IMPROVE TOWARDS A VFR/MVFR MIXTURE THROUGH 20Z SATURDAY. SLOW  
CLEARING THROUGH THE LATE AFTERNOON WILL GIVE WAY TO AN INCREASING  
SHOWERS AND THUNDERSTORM THREAT. START TIME FOR INCREASED SHOWERS  
AND THUNDERSTORMS STARTING AROUND 00Z SUNDAY. NORTH TO NORTHWESTERLY  
WINDS AT 5-10 KT WILL CONTINUE THROUGH 03Z-06Z SUNDAY, WHEN  
OFFSHORE NORTHEASTERLY FLOW WILL BEGIN TO DEVELOP. /42  
 

 
   
MARINE
 
NORTHERLY WINDS CONTINUE THROUGH THE WEEKEND, RISING  
TO DIURNAL PEAKS IN THE AFTERNOON AND EASING OVERNIGHT. A STEADY  
SLACKENING OF THE SURFACE PRESSURE GRADIENT WILL FAVOR LIGHTER  
WINDS THROUGH THE WEEKEND. A SMALL CRAFT ADVISORY REMAINS IN  
EFFECT BEYOND 10 NM SOUTH OF CAPE FALCON THROUGH ONLY 8 AM  
TODAY BEFORE GUSTS FALL BELOW 20 KT. SEAS OF 5-6 FT THIS MORNING  
WILL SLOWLY INCREASE TO 6-8 FT AS A LONG-PERIOD NORTHWEST SWELL  
ARRIVES THROUGH TODAY. A FURTHER SMALL CRAFT ADVISORY HAS BEEN  
HOISTED FOR 3-9 AM SUNDAY WITHIN THE COLUMBIA RIVER BAR AS A  
STRONG EBB CURRENT YIELDS STEEP SEAS OF 7-8 FT.  
 
A WIND REVERSAL ON MONDAY WILL SEE SOUTHERLY TO SOUTHWESTERLY  
FLOW CONTINUE THROUGH TUESDAY NIGHT, WITH INCREASED LOW MARINE  
STRATUS AND OVERNIGHT DRIZZLE OR LIGHT RAIN ACROSS NEARSHORE  
AREAS. MORE SEASONABLE NORTHERLY FLOW REDEVELOPS IN THE LATTER  
HALF OF THE WEEK WITH PERSISTENT SEAS OF 4-6 FT. -36  
 

 
   
CLIMATE
 
 
DAILY RECORD HIGH TEMPERATURES FOR SUNDAY, MAY 3  
 
LOCATION FORECAST RECORD YEAR  
 
ASTORIA 75 81 1992, 1944  
VANCOUVER 89 84 1944  
PORTLAND INT'L 91 89 1992  
HILLSBORO 89 82 2017  
MCMINNVILLE 86 87 1992  
SALEM 86 86 1992  
EUGENE 83 83 1944  
 

 
   
PQR WATCHES/WARNINGS/ADVISORIES
 
 
OR...HEAT ADVISORY FROM 8 AM TO 11 PM PDT SUNDAY FOR ORZ108-109-111-  
112.  
 
WA...HEAT ADVISORY FROM 8 AM TO 11 PM PDT SUNDAY FOR WAZ204>207.  
 
PZ...SMALL CRAFT ADVISORY FROM 3 AM TO 9 AM PDT SUNDAY FOR PZZ210.  
 

 
 

 
 
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X.COM/NWSPORTLAND  
 
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