786
FXUS66 KPQR 021000
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
300 AM PDT SAT MAY 2 2026
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
NORTHERLY FLOW AT THE SURFACE CONTINUES TO SUPPORT A
MVFR/IFR MARINE LAYER ALONG THE COAST. FLIGHT CONDITIONS ALONG
THE COAST ARE EXPECTED TO BECOME MORE IFR/LIFR FROM 07Z-10Z
SATURDAY, WITH A HIGHER PROBABILITY OF LIFR CONDITIONS FOR KAST.
WHILE NORTHERLY FLOW AT THE SURFACE IS PRESENT FOR INLAND
TERMINALS, THERE IS SOUTHERLY FLOW ALOFT (WHICH CAN BE OBSERVED
VIA SATELLITE). THIS PATTERN IS MAINTAINING HIGH LEVEL CLOUDS
ACROSS THE AIRSPACE ABOVE FL200-FL250. WEST TO NORTHWEST WINDS AT
THE SURFACE 5-10 KT THROUGH THE EVENING, BECOMING LIGHT AND
VARIABLE OVERNIGHT. EXPECT SLOWLY LOWERING CIGS DOWN TOWARDS
FL050-FL100 AROUND THROUGH 10Z SAT.
RADAR IS ALSO SHOWING SOME SHOWERS ALONG THE CASCADES AND THEY
ARE HIGH BASED. THERE ARE SOME EMBEDDED THUNDERSTORMS WITHIN
THESE SHOWERS AND AS THE UPPER LEVEL FLOW SLOWLY BECOMES MORE
SOUTHEASTERLY THROUGH THE TAF PERIOD, THESE SHOWER COULD PUSH
FURTHER INLAND, RESULTING IN BRIEF PERIODS OF MVFR CONDITIONS.
GENERAL INSTABILITY WILL CONTINUE TO DECREASE AS SURFACE CONDITIONS
COOL. STILL, THE LOCATION AND TIMING OF ANY SHOWERS IS UNCERTAIN,
WITH CONFIDENCE IN ANY IMPACTS TO TERMINALS REMAINING VERY LOW.
KPDX AND APPROACHES...VFR CONDITIONS BENEATH INCREASING HIGH
CLOUDS EXPECTED THROUGH THE PERIOD, WITH CIGS FALLING FROM
FL200-FL250 TOWARDS FL100 THROUGH 08Z SATURDAY. NORTHWEST WINDS
TO 5-10 KT EASING BELOW 5 KT AROUND 06Z SATURDAY. /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.
SMALL CRAFT ADVISORY UNTIL 2 AM PDT EARLY THIS MORNING FOR
PZZ252-253-271.
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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