581
FXUS66 KPQR 030403 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
903 PM 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
UPPER LEVEL HIGH
PRESSURE SITS WEST OF WA AND OR WITH A SHORTWAVE TROUGH PINCHING
OFF SOUTHWARD TOWARD SOUTHERN OR AND NORTHERN CA TODAY. THE
SHORT WAVE PINCHES OFF INTO A CLOSED LOW TONIGHT INTO SUNDAY
MORNING DEEPENING OFF THE CA COAST WHILE UPPER LEVEL HIGH
PRESSURE OVER THE NORTHEAST PACIFIC BUILDS INTO THE PACNW.
THE TROUGH PINCHING OFF TO THE SOUTH WILL SUPPORT SOUTHEAST FLOW
IN THE UPPER LEVELS WHICH WILL ADVECT VORTICITY OVER NORTHWEST
OR. THIS IS A FAVORABLE SET-UP FOR SOME CONVECTION DEVELOPING
ALONG WEST SIDE OF THE CASCADES AND POSSIBLY DRIFTING TOWARD THE
FOOTHILLS AND WILLAMETTE VALLEY ALONG THAT SOUTHEAST FLOW.
SURFACE BASED INSTABILITY IS EXPECTED TO INCREASE AS DAYTIME
HEATING CONTINUES AND CLOUD COVER THINS THIS AFTERNOON.
EXPECTING SURFACE CAPE BETWEEN 500-1000 J/KG OVER THE WILLAMETTE
VALLEY AND PORTLAND-VANCOUVER METRO WITH VALUES CLOSER TO 1500
J/KG OVER THE FOOTHILLS AND CASCADES. HI-RES MODELS DO SHOW
POTENTIAL FOR SOME CONVECTION TO DEVELOP OVER THE HIGHER TERRAIN
AND DRIFT INTO THE VALLEY WITH A ~15-30% CHANCE THROUGH THIS
EVENING. FORTUNATELY, THIS DOES NOT LOOK LIKE A GOOD SEVERE
THUNDERSTORM ENVIRONMENT. FACTORS SUCH AS SHEAR AD HELICITY ARE
LACKING THOUGH THERE IS A SMALL AMOUNT OF DCAPE WHICH COULD
SUPPORT SOME STRONG, SUB-SEVERE WIND GUSTS WITHIN ANY STORM
THAT DOES DEVELOP. THE HIGHEST THUNDERSTORM THREAT REMAINS OVER
THE LANE, LINN, AND MARION COUNTY CASCADES AT 25-30% WITH LOWER
CHANCES IN THE WILLAMETTE VALLEY AND SOUTH OF THE COLUMBIA
RIVER AT 15-25%. THUNDERSTORM ACTIVITY WANES THIS EVENING AS
INSTABILITY DROPS OFF AFTER PEAK HEATING.
AS THE UPPER LOW DRIFTS SOUTHWARD AND PINCHES OFF, RIDGING MOVES
OVERHEAD TONIGHT INTO SUNDAY. AN INVERTED SURFACE TROUGH WILL
DEVELOP OVERNIGHT, SUPPORTING OFFSHORE WINDS ON THE WEST SIDE OF
THE CASCADES AND COAST RANGE. DESPITE A CLEARING TREND TONIGHT,
LOWS EXPECTED TO REMAIN MILD IN THE LOW TO MID 50S AS EASTERLY
FLOW DEVELOPS. THERE IS A CHANCE THAT LOWS FAIL TO DIP BELOW 60
FOR LOCATIONS WITHIN THE COLUMBIA RIVER GORGE AND AROUND THE
PORTLAND-VANCOUVER METRO, WITH A A 40-60% CHANCE AND A 10-20%
CHANCE RESPECTIVELY. 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. -19/36
LONG TERM...MONDAY THROUGH SATURDAY
TEMPERATURES ARE
EXPECTED TO MODERATE BACK INTO THE 70S FOR MONDAY AND THROUGH
MUCH OF THE WORK WEEK AS THE RIDGE AXIS SHIFTS INLAND. HIGHS
WILL STILL RUN 5-10 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR.
WINDS TURN SOUTHERLY WITH THE RIDGE SHIFTING EASTWARD WHICH WILL
HELP SUPPORT CHANCES FOR MARINE STRATUS TO DEVELOP ALONG THE
COAST. ENSEMBLES SHOW A STRONG CONSENSUS FOR DRY CONDITIONS
THROUGH THE WORKWEEK FOR MUCH OF THE AREA. HOWEVER, THERE IS A
LOW (10-20%) CHANCE FOR A POP-UP SHOWER OR THUNDERSTORM OVER
THE LANE AND LINN COUNTY CASCADES BOTH MONDAY AND TUESDAY
AFTERNOON. COULD ALSO SEE SOME LIGHT DRIZZLE ALONG THE COAST IF
THE MARINE STRATUS IS THICK ENOUGH.
CLUSTER ANALYSIS FAVORS THE RIDGE FLATTENING OUT TOWARD THE END
OF THE WEEK AS A SHORTWAVE RIDES OVER THE RIDGE. THIS COULD LEAD
TO A PATTERN SHIFT BACK TO COOLER TEMPERATURES AND LOW CHANCES
FOR LIGHT RAIN. -19
AVIATION
PREDOMINATELY, VFR ACROSS THE AIRSPACE THROUGH AROUND
06Z SUNDAY. SHOWERS AND THUNDERSTORMS CONTINUE TO SLOWLY
DISSIPATE THROUGH 05Z SUNDAY. NORTH/NORTHWEST WINDS AT 5-10 KT
WILL CONTINUE THROUGH 06Z SUNDAY. AFTERWARDS, NORTHEASTERLY FLOW
WILL BEGIN TO DEVELOP. EXPECT IFR/LIFR CONDITIONS TO RETURN TO
COAST AS MARINE STRATUS RETURNS STARTING AROUND 06Z-08Z SUNDAY.
ANY LOWERED FLIGHT CONDITIONS SHOULD START TO IMPROVE TOWARDS VFR
AROUND 20Z-22Z SUNDAY. AFTER 22Z SUNDAY, WIDESPREAD VFR CONDITIONS
EXPECTED WITH IFR MARINE STRATUS RETURNING TO THE COAST TOWARDS
THE END OF THE TAF PERIOD.
KPDX AND APPROACHES...GENERALLY VFR CONDITIONS THROUGH THE TAF
PERIOD. NORTH/NORTHWEST WINDS AT 5-10 KT WILL CONTINUE THROUGH
03Z-06Z SUNDAY AFTERWARDS, NORTHEASTERLY FLOW WILL BEGIN TO
DEVELOP. /42
MARINE
NORTHERLY WINDS CONTINUE THROUGH THE WEEKEND, WITH
PEAK GUSTS EXPECTED AFTERNOON AND EASING OVERNIGHT. A STEADY
WEAKENING OF THE SURFACE PRESSURE GRADIENT WILL FAVOR LIGHTER
WINDS THROUGH THE WEEKEND. SEAS OF 5-6 FT THIS MORNING WILL
SLOWLY BUILD TOWARDS 6-8 FT AS A LONG-PERIOD NORTHWEST SWELL
ARRIVES. WILL MAINTAIN THE CURRENT SMALL CRAFT ADVISORY FOR 3-9
AM SUNDAY WITHIN THE COLUMBIA RIVER BAR AS A STRONG EBB CURRENT
YIELDS STEEP SEAS OF 7-8 FT.
A SOUTHERLY WIND REVERSAL IS EXPECTED ON MONDAY, WHICH WILL BRING
AN RETURN TO MARINE STRATUS ALONG THE COAST THROUGH TUESDAY NIGHT.
THIS WILL ALSO BRING OVERNIGHT AGGRESSIVE DRIZZLE/LIGHT RAIN
TO THE COAST. NORTHERLY WINDS RETURN TOWARDS THE LATTER PART OF
THE WEEK WITH SEAS OF 4-6 FT. /42-36
CLIMATE
DAILY RECORD HIGH TEMPERATURES FOR SUNDAY, MAY 3
LOCATION FORECAST RECORD YEAR
ASTORIA 76 81 1992, 1944
VANCOUVER 90 84 1944
PORTLAND INT'L 91 89 1992
HILLSBORO 90 82 2017
MCMINNVILLE 87 87 1992
SALEM 87 86 1992
EUGENE 85 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.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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