275
FXUS66 KPQR 021135
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
435 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
MIXED VFR/MVFR FLYING CONDITIONS ARE IN PLACE EARLY
THIS MORNING ACROSS THE REGION AS MARINE STRATUS REACHES INLAND.
LOW-END MVFR CIGS ARE FAVORED TO PERSIST AT COASTAL TERMINALS
THROUGH 19-22Z SAT UNTIL LOW CLOUDS MIX OUT AND CONDITIONS
RETURN TO VFR. NORTH TO NORTHWESTERLY WINDS AT 5-10 KT WILL
CONTINUE THROUGH 03-06Z SUN, WHEN OFFSHORE NORTHEASTERLY FLOW
WILL BEGIN TO DEVELOP. A NARROW TONGUE OF MARINE STRATUS ALONG
THE CENTRAL OR COAST MAY AGAIN RESULT IN MVFR CIGS SOUTH OF
KTMK, WHILE CLEARER SKIES ARE MORE LIKELY TO THE NORTH.
INLAND, MVFR CIGS HAVE REACHED EASTWARD ALONG THE LOWER COLUMBIA
RIVER TO PORTLAND-AREA TERMINALS INCLUDING AT KPDX/KVUO/KTTD.
MARINE STRATUS WILL ALSO CONTINUE TO PUSH INLAND THROUGH COAST
RANGE GAPS TO THE SOUTHERN WILLAMETTE VALLEY, WITH 50-60%
CHANCES OF MVFR CIGS AT KEUG/KCVO AFTER 14-15Z SAT. ACROSS THE
NORTHERN WILLAMETTE VALLEY INCLUDING KUAO/KSLE, STRATUS
DEVELOPMENT AGAINST THE CASCADE FOOTHILLS IS EXPECTED TO SUPPORT
LOW-END VFR CIGS, WHILE CHANCES FOR BASES TO LOWER TO MVFR
LEVELS REACHES ONLY 20-40% THROUGH 18Z SAT. TERMINALS TO THE
WEST OF THE WILLAMETTE RIVER (KMMV/KHIO) ARE MUCH LESS LIKELY TO
SEE MVFR CIGS EARLY THIS MORNING. ANY LOW CLOUDS WILL TEND TO
MIX OUT BY 17-19Z SAT, WITH VFR CONDITIONS THEN FAVORED THROUGH
THE REMAINDER OF THE PERIOD. DIURNAL NORTHERLY WINDS WILL BUILD
TO AROUND 5 KT THIS AFTERNOON, THEN EASE BY 03-06Z SUN. AFTER
21Z SAT, SHOWERS AND THUNDERSTORMS (15-35% CHANCE) MAY BEGIN TO
DEVELOP ON THE WEST SIDE OF THE CASCADE CREST. WHILE ANY STORMS
ARE EXPECTED TO TRACK TO THE NORTHWEST, CONFIDENCE IN ANY
CONVECTIVE PRECIPITATION AT AREA TERMINALS IS TOO LOW TO INCLUDE
IN TAFS AT THIS LEAD TIME. ANY SHOWERS OR STORMS WILL TEND TO
DISSIPATE AFTER 03Z SUN.
KPDX AND APPROACHES...AN INLAND PUSH OF MARINE STRATUS HAS
RESULTED IN MVFR CIGS AROUND 1.5-2 KFT EARLY THIS MORNING, AND
IS FAVORED TO PERSIST THROUGH 17-19Z SAT. SKIES WILL TREND
CLEARER AS LOW CLOUDS MIX OUT THIS AFTERNOON. SHOWERS AND
THUNDERSTORMS DEVELOPING OVER THE CASCADES WILL TRACK TO THE
NORTHWEST, BUT THERE CHANCES OF TERMINAL IMPACTS ARE VERY LOW.
DIURNAL NORTH TO NORTHWEST WINDS WILL BUILD TO AROUND 5 KT THIS
AFTERNOON, THEN EASE AFTER 03-06Z SUN. -36
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.
SMALL CRAFT ADVISORY UNTIL 8 AM PDT THIS MORNING FOR PZZ272-
273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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