739
FXUS66 KPQR 230520 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1020 PM PDT MON JUN 22 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
HOT WEATHER REMAINS THE PRIMARY CONCERN THROUGH
TUESDAY, THOUGH FORECAST TEMPERATURES HAVE TRENDED A BIT LOWER
COMPARED TO EARLIER EXPECTATIONS. INLAND HIGHS WILL STILL REACH
THE 90S THROUGH TUESDAY, WHILE SOMEWHAT COOLER OVERNIGHT LOWS
SHOULD OFFER AT LEAST MODEST RELIEF IN SOME AREAS. TEMPERATURES
BEGIN EASING WEDNESDAY, THOUGH INLAND CONDITIONS REMAIN ABOVE
NORMAL, AND A LOW-END THUNDERSTORM THREAT MAY DEVELOP. A BROADER
SHIFT TOWARD COOLER, MORE UNSETTLED WEATHER IS THEN FAVORED
LATE WEEK INTO NEXT WEEKEND.
DISCUSSION...NOW THROUGH SUNDAY
AS OF LATE MONDAY AFTERNOON,
THE FORECAST REMAINS BROADLY ON TRACK, WITH UPPER-LEVEL RIDGING
STILL THE DOMINANT FEATURE OVER THE PACIFIC NORTHWEST. A DRY AND
WARM AIR MASS REMAINS IN PLACE, AND AFTER MORNING COASTAL
STRATUS MIXED OUT, TEMPERATURES ROSE EFFICIENTLY THROUGH THE DAY
INLAND. EVEN WITH A SLIGHT DOWNWARD ADJUSTMENT TO THE
TEMPERATURE FORECAST, READINGS STILL CLIMBED WELL ABOVE NORMAL
THIS AFTERNOON, WITH MANY INTERIOR VALLEY LOCATIONS REACHING
THE UPPER 80S TO LOWER 90S.
HEAT REMAINS THE MAIN FORECAST CONCERN THROUGH TUESDAY, ALTHOUGH
BOTH AFTERNOON HIGHS AND OVERNIGHT LOWS HAVE TRENDED SOMEWHAT
LOWER THAN EARLIER FORECASTS. THE MORE NOTABLE CHANGE HAS BEEN
ON THE OVERNIGHT SIDE, WHERE LOWS TONIGHT AND AGAIN TUESDAY
NIGHT NOW APPEAR MORE LIKELY TO PROVIDE SOMEWHAT BETTER RELIEF
THAN PREVIOUSLY EXPECTED. EVEN SO, MANY INLAND AREAS WILL REMAIN
QUITE WARM DURING THE DAY, WITH HIGHS STILL EXPECTED TO REACH
THE 90S THROUGH TUESDAY. THIS WILL CONTINUE TO SUPPORT
WIDESPREAD MODERATE HEATRISK ACROSS THE INTERIOR VALLEYS,
ESPECIALLY FOR THOSE SENSITIVE TO HEAT OR WITHOUT EFFECTIVE
COOLING.
TUESDAY STILL LOOKS HOT, EVEN AS THE OVERALL TEMPERATURE
FORECAST COMES DOWN SLIGHTLY. MUCH OF THE INTERIOR VALLEY SHOULD
AGAIN WARM INTO THE LOW TO MID 90S, WHILE AREAS FROM SALEM
NORTHWARD INTO THE PORTLAND/VANCOUVER METRO MAY STILL SEE WARMER
OVERNIGHT LOWS THAN SURROUNDING LOCATIONS DUE TO URBAN HEAT
RETENTION. THE HEAT ADVISORY REMAINS IN EFFECT THROUGH TUESDAY
EVENING FOR THE I-5 CORRIDOR FROM SALEM TO THE COWLITZ VALLEY,
ALONG WITH THE COLUMBIA RIVER GORGE AND UPPER HOOD RIVER VALLEY.
ANYONE WITH OUTDOOR PLANS SHOULD CONTINUE TAKING BASIC HEAT
PRECAUTIONS, INCLUDING STAYING HYDRATED, SEEKING SHADE, AND
LIMITING STRENUOUS ACTIVITY DURING THE WARMEST PART OF THE DAY.
A TRANSITION BEGINS WEDNESDAY AS THE RIDGE WEAKENS AND MARINE
INFLUENCE GRADUALLY INCREASES. TEMPERATURES WILL TREND LOWER,
BUT INLAND HIGHS ARE STILL EXPECTED TO REMAIN ABOVE NORMAL,
GENERALLY IN THE UPPER 80S TO LOWER 90S. IN ADDITION, SPC HAS
INTRODUCED A GENERAL THUNDERSTORMS RISK FOR WEDNESDAY ACROSS
THE CASCADES/FOOTHILLS. CONFIDENCE REMAINS LOW, BUT A FEW
THUNDERSTORMS CANNOT BE RULED OUT AS THE PATTERN BECOMES LESS
STABLE. WHILE SOME MODELS SUGGEST CAPE VALUES AS HIGH AS 1200
J/KG AND BULK SHEAR AROUND 20 KT, THE CHANCE OF PRECIPITATION
IS SO LOW THAT THOSE SAME MODELS BARELY SUGGEST ENOUGH
SATURATION FOR THUNDERSTORM DEVELOPMENT.
THE LARGER-SCALE PATTERN CHANGE STILL APPEARS ON TRACK FOR LATE
THURSDAY INTO FRIDAY AS UPPER-LEVEL TROUGHING MOVIES INTO THE
PACIFIC NORTHWEST. THIS SHOULD BRING A MORE NOTICEABLE TURN
TOWARD COOLER AND MORE UNSETTLED CONDITIONS, ALONG WITH
INCREASING CHANGES FOR RAINFALL ACROSS MUCH OF NORTHWEST OREGON
AND SOUTHWEST WASHINGTON. THERE IS ALSO A LOW CHANCE OF
THUNDERSTORMS LINGERING INTO SATURDAY, PARTICULARLY ACROSS THE
INTERIOR VALLEYS AND CASCADES/FOOTHILLS.
BEYOND THAT, ENSEMBLE GUIDANCE CONTINUES TO FAVOR GENERALLY
SEASONABLE TO SLIGHTLY COOL CONDITIONS HEADING INTO NEXT
WEEKEND. WHILE THE EXACT TIMING AND COVERAGE OF PRECIPITATION
LATER THIS WEEK STILL CARRIES SOME UNCERTAINTY, CONFIDENCE IS
INCREASING THAT THE PROLONGED HOT AND DRY PATTERN WILL GIVE WAY
TO A MORE TYPICAL LATE-JUNE REGIME BY THE END OF THE WEEK.
~12
AVIATION
WESTERLY FLOW ALOFT WITH WEAK UPPER LEVEL RIDGING WILL
MAINTAIN HIGH PRESSURE OVER THE REGION THROUGH TUESDAY. LOW
MARINE STRATUS AND AREAS OF FOG CONTINUE AT THE COAST AS OF 05Z
TUESDAY, IMPACTING KONP WITH LIFR CEILINGS AND VISIBILITIES
THROUGH AT LEAST 18Z TUESDAY. FOG AND LOW STRATUS HAS NOT PUSHED
FAR ENOUGH INLAND TO IMPACT KAST, HOWEVER THERE IS A 20-30% CHANCE
LOW STRATUS OR FOG WILL DEVELOP OVER THE TERMINAL AT ANY POINT IN
TIME NOW THROUGH 13Z TUESDAY. THIS IS NOT REFLECTED IN THE TAF AS
THE CONTINUATION OF MOSTLY CLEAR SKIES AND VFR CONDITIONS IS THE
MOST LIKELY OUTCOME.
INLAND TERMINALS WILL REMAIN MOSTLY CLEAR THROUGH 06Z WEDNESDAY,
ASIDE FROM A PERIOD OF HIGH CLOUDS TUESDAY MORNING AND AFTERNOON.
HOWEVER, CEILINGS ARE EXPECTED TO BE ABOVE 20-25 KFT WITH THESE
HIGH CLOUDS. LIGHT AND VARIABLE WINDS TONIGHT WILL INCREASE OUT OF
THE NORTH TUESDAY AFTERNOON OVER THE WILLAMETTE VALLEY. IN
ADDITION, HIGH TEMPERATURES BETWEEN 90 TO 95 DEGREES ARE FORECAST
ACROSS THE WILLAMETTE VALLEY ON TUESDAY. BE AWARE OF HIGH DENSITY
ALTITUDE WHICH MAY REDUCE AIRCRAFT PERFORMANCE.
KPDX AND APPROACHES...VFR CONDITIONS ARE EXPECTED THROUGH THE TAF
PERIOD WITH MOSTLY CLEAR SKIES, EXCEPT FOR A PERIOD OF HIGH
CLOUDS WITH CEILINGS OVER 20-25 KFT TUESDAY MORNING AND AFTERNOON.
WEST-NORTHWEST WINDS AROUND 7-8 KT MONDAY EVENING SHOULD BECOME
LIGHT AND VARIABLE AROUND 5 KT OR LESS BY 08Z TUESDAY. WINDS WILL
MOST LIKELY INCREASE OUT OF THE NORTH BY EARLY TUESDAY AFTERNOON,
SUSTAINED BETWEEN 7-10 KT. HOWEVER, THERE IS SOME UNCERTAINTY
REGARDING THE EXACT WIND DIRECTION TUESDAY AFTERNOON. ALTHOUGH
NORTHERLY WINDS ARE THE MOST LIKELY OUTCOME, THERE IS AROUND A 40%
CHANCE THE WIND DIRECTION WILL BECOME EASTERLY TO NORTHEASTERLY.
-23
MARINE
HIGH PRESSURE OFFSHORE WILL MAINTAIN BREEZY NORTH TO
NORTHWEST WINDS ACROSS THE COASTAL WATERS THROUGH WEDNESDAY. WINDS
GENERALLY EXPECTED TO REMAIN UNDER 20 KT, THOUGH GUSTS UP TO 25 KT
ARE POSSIBLE ACROSS THE OUTER WATERS SOUTH OF CAPE FALCON THROUGH
TONIGHT. SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR THESE WATERS
THROUGH 5 AM TUESDAY. WEAKENING HIGH PRESSURE WILL GIVE WAY TO A
FRONTAL SYSTEM APPROACHING THE AREA ON THURSDAY. WINDS ARE
EXPECTED TO BACK WEST TO SOUTHWESTERLY BEFORE THE COLD FRONT
PUSHES ACROSS THE COASTAL WATERS LATE THURSDAY INTO FRIDAY.
SOUTHWEST WINDS ARE EXPECTED TO BE STRONGEST ACROSS THE NORTHERN
INNER WATERS, BUT ONLY AROUND A 10-20% CHANCE OF GUSTS REACHING
SCA THRESHOLDS THROUGH FRIDAY MORNING. WEST TO NORTHWEST WINDS
WILL PERSIST BEHIND THE FRONT LATER FRIDAY AND INTO THE WEEKEND AS
WEAK LOW PRESSURE LINGERS NEAR VANCOUVER ISLAND. HIGH PRESSURE
GRADUALLY BUILDS ACROSS THE WATERS LATE WEEKEND. SEAS REMAIN
RELATIVELY STEEP AND CHOPPY AROUND 5 TO 6 FT THROUGH WEDNESDAY,
SUBSIDING TO 4 TO 5 FT THURSDAY INTO FRIDAY. /DH
PQR WATCHES/WARNINGS/ADVISORIES
OR...HEAT ADVISORY UNTIL 11 PM PDT TUESDAY FOR ORZ108>115-119>123.
WA...HEAT ADVISORY UNTIL 11 PM PDT TUESDAY FOR WAZ204>210.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT TUESDAY FOR PZZ272-273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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