436
FXUS66 KPQR 241125
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
425 AM PDT MON AUG 24 2026
SYNOPSIS
UPPER LEVEL RIDGING AND LOW-LEVEL OFFSHORE FLOW
DEVELOPS TODAY, CONTINUING INTO TUESDAY, BRINGING WARMER AND
SUNNIER CONDITIONS WITH HIGH TEMPERATURES IN THE LOWER 90S TODAY
AND UPPER 80S TUESDAY ACROSS THE INTERIOR LOWLANDS. WILDFIRE
SMOKE WILL ALSO BEGIN TO INCREASE OVER THE COLUMBIA RIVER GORGE,
UPPER HOOD RIVER VALLEY, AND THE GREATER PORTLAND/VANCOUVER
METRO AREA THIS MORNING AND THEN LINGER THROUGH TUESDAY;
HOWEVER SMOKE IS NOT EXPECTED TO BE DENSE FOR MOST LOCATIONS.
ONSHORE FLOW ARRIVES BY WEDNESDAY AND CONTINUES THEREAFTER,
WHICH WILL CLEAR ANY LINGERING SMOKE OUT OF THE AREA AND BRING
COOLER, MORE SEASONABLE TEMPERATURES THROUGH THE END OF THE
WEEK AND INTO THE WEEKEND.
SHORT TERM...NOW THROUGH TUESDAY NIGHT
A BUILDING UPPER
LEVEL RIDGE WILL BRING A WARM START TO THE WORK WEEK AS A
THERMAL TROUGH DEVELOPS OVER THE AREA TODAY. OFFSHORE FLOW IS
WILL DEVELOP ON THE WESTERN SLOPES OF THE CASCADES AND COAST
RANGE THIS AFTERNOON, HELPING SUPPORT THE WARMER TEMPERATURES.
WINDS ARE NOT EXPECTED TO BE PARTICULARLY STRONG BUT COULD BE
GUSTY IN THE WESTERN COLUMBIA RIVER GORGE WITH GUSTS OF 25-35
MPH POSSIBLE LATE THIS MORNING THROUGH THE AFTERNOON. 850 MB
TEMPERATURES ARE EXPECTED TO RISE TO BETWEEN 18-22 C SUPPORTING
A NOTICEABLE JUMP IN HIGH TEMPERATURES FROM YESTERDAY.
10TH-90TH PERCENTILES FOR HIGHS SHOW A SMALL RANGE IN THE LOW TO
MID 90S FOR INTERIOR LOWLANDS AND UPPER 60S TO LOW 70S ALONG
THE COAST. OFFSHORE WINDS WILL ALSO BRING SOME NOTICEABLE
WILDFIRE SMOKE TO PORTIONS OF THE CENTRAL AND NORTHERN
WILLAMETTE VALLEY, THE PORTLAND METRO AND THE WESTERN COLUMBIA
RIVER GORGE. DEPENDING ON HOW THICK THIS SMOKE IS, IT COULD
IMPACT AFTERNOON HIGHS BY KNOCKING THEM DOWN A DEGREE OR TWO.
AFTERNOON SEA BREEZES RETURN LIGHT ONSHORE FLOW ALONG THE COAST
AND WESTERN PORTIONS OF THE COAST RANGE. A WEAK PASSING
DISTURBANCE MAY BRIEFLY DECREASE OFFSHORE WINDS ALONG THE
WESTERN SLOPES OF THE CASCADES DURING THE LATE AFTERNOON AND
EVENING HOURS BUT OFFSHORE FLOW RETURNS LATE IN THE EVENING
INTO THE OVERNIGHT HOURS. OVERNIGHT TEMPERATURES IN THE
PORTLAND METRO AND CASCADE VALLEYS AND FOOTHILLS WILL BE RATHER
MILD IN THE LOW TO MID 60S WHILE TEMPS DROP INTO THE MID 50S
ELSEWHERE.
TROUGHING OVER THE GULF OF ALASKA IS EXPECTED TO SLOWLY DRIFT
SOUTHEAST WHILE A SHORTWAVE OVER THE NORTHEAST PACIFIC GETS SWUNG
TOWARD THE PACNW EARLY TUESDAY. THIS WILL BRING SLIGHTLY LOWER
HEIGHTS ALOFT AND A DECREASE IN 850 MB TEMPERATURES TO AROUND 16-18
C BUT WILL STILL SUPPORT HIGH TEMPERATURES IN THE MID TO UPPER
80S ACROSS THE INTERIOR LOWLANDS AND 60S ALONG THE COAST. WINDS
WILL ALSO SHIFT ONSHORE ACROSS THE ENTIRE AREA. BY TUESDAY
EVENING, SURFACE HIGH PRESSURE BUILDING ALONG THE COAST WILL
BRING A STRONG MARINE PUSH OF WESTERLY WINDS. ANY LINGERING
WILDFIRE SMOKE SHOULD SHIFT BACK EAST OF THE CASCADES BY
WEDNESDAY. -19
LONG TERM...WEDNESDAY THROUGH SUNDAY
CONFIDENCE REMAINS HIGH
HEADING INTO THE LATTER HALF OF THE WEEK AND INTO THE WEEKEND.
CLUSTER ANALYSIS IS HEAVILY FAVORING TROUGHING OVER THE PACNW
AND WESTERN CANADA WITH SEVERAL EMBEDDED IMPULSES REINFORCING
THIS PATTERN FOR SEVERAL DAYS. THIS WILL BRING A SIGNIFICANT
DOWNWARD TREND IN TEMPERATURES STARTING WEDNESDAY WITH HIGHS
CLOSE TO AVERAGE THEN GRADUALLY DROPPING INTO THE UPPERS 70S
THURSDAY AND FRIDAY AND POSSIBLY THE MID 70S BY SATURDAY.
PRECIPITATION SIGNALS REMAIN WEAK BUT THE BEST CHANCE FOR LIGHT
RAIN LOOKS TO BE SATURDAY, THOUGH THERE IS SIGNIFICANT MODEL
SPREAD THIS FAR OUT. COULD SEE SOME LIGHT DRIZZLE ASSOCIATED
WITH WEAK FRONTAL PASSAGES THURSDAY MORNING AND A BETTER CHANCE
SATURDAY. -19
AVIATION...12Z TAFS
NORTH WINDS HAVE KEPT MARINE STRATUS JUST
OFF THE COAST BUT HAVE STARTED TO SEE SOME LOWER CLOUDS DEVELOP
RIGHT ALONG THE STRIP. THIS IS SUPPORTING LIFR CONDITIONS AT
KAST AND MVFR CONDITIONS AT KONP. GUIDANCE IS STRUGGLING WITH
THIS SET-UP WITH JUST SLIGHT CHANGES IN THE WIND DIRECTION
LIKELY SUPPORTING DRASTIC CHANGES IN CIGS AND THEREFORE
FLIGHT LEVEL ALONG THE COAST. COULD SEE INTERMITTENT CIG
RESTRICTIONS THROUGH 16Z ALONG THE COAST. INLAND CONDITIONS
LIKELY REMAIN VFR THOUGH GUIDANCE DOES SUGGEST SOME STRATUS
DEVELOPING IN THE EASTERN WILLAMETTE VALLEY AND PORTLAND METRO.
COULD SEE SOME BRIEF CIG IMPACTS AT KSLE, KEUG, KTTD AND MAYBE
KPDX BETWEEN THROUGH 16-18Z.
NORTH/NORTHEAST WINDS THROUGH THE TAF PERIOD. EXPECT BREEZY WINDS
GUSTING AROUND OF 20 KT AT KONP. AROUND 18-20Z, EASTERLY WINDS
AROUND 8-11 KT ARE EXPECTED TO DEVELOP AT KTTD AND KPDX AS
OFFSHORE WINDS DEVELOP THROUGH THE COLUMBIA RIVER GORGE. THE
NORTH/NORTHEAST WINDS WILL ALSO PUSH SOME WILDFIRE SMOKE/HAZE
INTO THE WILLAMETTE VALLEY.
SMOKE/HAZE WILL HAVE THE POTENTIAL REDUCE VERTICAL AND SLANTWISE
VISIBILITIES AT TIMES. IN ADDITION, TEMPERATURES ARE EXPECTED TO
WARM INTO THE LOWER 90S THIS AFTERNOON AT THE INLAND TAF SITES,
SO BE AWARE OF HIGH DENSITY ALTITUDE WHICH MAY REDUCE AIRCRAFT
PERFORMANCE.
KPDX AND APPROACHES...NORTH/NORTHEAST WINDS THROUGH THE TAF
PERIOD WITH MORE EASTERLY WINDS DEVELOPING AROUND 18-20Z.
EXPECT 8-11 KT TO DEVELOP NEAR AND EAST OF THE TERMINAL AS
EASTERLY WINDS DEVELOP THROUGH THE COLUMBIA RIVER GORGE.
SMOKE/HAZE WILL HAVE THE POTENTIAL REDUCE VERTICAL AND SLANTWISE
VISIBILITIES AT TIMES. IN ADDITION, TEMPERATURES ARE EXPECTED
TO WARM INTO THE LOWER 90S THIS AFTERNOON AT THE INLAND TAF
SITES, SO BE AWARE OF HIGH DENSITY ALTITUDE WHICH MAY REDUCE
AIRCRAFT PERFORMANCE. -19/42
MARINE
GUSTY NORTHERLY WINDS PERSIST THROUGH THE AFTERNOON
ACROSS ALL WATERS WITH GUSTS UP TO 25 KT EXPECTED. WINDS
DECREASE FROM FROM SOUTH TO NORTH THIS EVENING. THE SMALL CRAFT
ADVISORY (SCA) FROM FLORENCE TO CAPE FALCON WILL DROP OFF FIRST
AT 5 PM AND THE SCA FOR WATERS NORTH OF CAPE FALCON TO CAPE
SHOALWATER AND THE COLUMBIA RIVER BAR ARE EXPECTED TO END AT 8
PM AS WINDS DECREASE.
A SOUTHERLY WIND REVERSAL ARRIVES EARLY TUESDAY MORNING OVER THE
INNER WATERS WITH GUSTS UP TO 15-20 KT EXPECTED BY TUESDAY
AFTERNOON OVER THE NORTHERN INNER WATERS. THIS WILL ALSO BRING
INCREASING CHANCES FOR MARINE FOG BEGINNING EARLY TUESDAY
MORNING, ESPECIALLY OVER THE INNER WATERS. VISIBILITIES MAY FALL
BELOW 1 SM AT TIMES AS THE SOUTHERLY WINDS DEVELOP AND
UPWELLING OCCURS. ASIDE FROM THE INCREASING WINDS AND POTENTIAL
MARINE FOG, SIGNIFICANT WAVE HEIGHTS LOOK TO REMAIN RELATIVELY
LOW AT AROUND 3 TO 5 FT THROUGH FRIDAY. -19/23
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 8 PM PDT THIS
EVENING FOR PZZ210.
SMALL CRAFT ADVISORY UNTIL 8 PM PDT THIS EVENING FOR PZZ251-
271.
SMALL CRAFT ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR PZZ252-
253-272-273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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