370
FXUS66 KPQR 162122
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
222 PM PDT TUE SEP 16 2025
SYNOPSIS
DRY, OFFSHORE FLOW WILL CONTINUE TO SUBSIDE THROUGH
THE EVENING. ONSHORE FLOW RETURNS TONIGHT AS A WEAK FRONT
BRUSHES THE COAST. A BROADER TROUGH MOVING INTO THE REGION FROM
THE NORTHEAST PACIFIC WILL BRING BETTER RAIN CHANCES TOWARDS THE
END OF THE WEEK AND INTO THE WEEKEND, ESPECIALLY NEAR THE COAST
AND ACROSS SOUTHWEST WASHINGTON.
SHORT TERM...NOW THROUGH THURSDAY NIGHT
CLEAR SKIES, DRY
CONDITIONS AND OFFSHORE WINDS WILL PERSIST THROUGH THE EARLY
EVENING. A PATTERN CHANGE IS ON DECK FOR TONIGHT THROUGH
WEDNESDAY MORNING AS A WEAK FRONTAL PASSAGE WILL BRING COOL,
MOIST ONSHORE FLOW BACK INTO THE REGION. NORMALLY, A FRONTAL
PASSAGE WILL BRING THE POTENTIAL FOR PRECIPITATION, BUT WITH
THE DRY AIR OVER THE REGION AND THE OVERALL WEAKNESS OF THE
FRONT AM NOT EXPECTING ANY PRECIPITATION TO REACH THE COAST.
HOWEVER, COOL AND MOIST CONDITIONS WILL PERSIST AND RESULT IN
DAYTIME HIGHS WEDNESDAY IN THE UPPER 60S TO LOW 70S ALONG THE
COAST AND UPPER 70S TO LOW 80S INLAND. THURSDAY LOOKS TO BE A
FEW DEGREES COOLER WITH DAYTIME HIGHS IN THE THE UPPER 60S TO
LOW 70S ALONG THE COAST AND UPPER 70S TO LOW 80S INLAND. LOW TO
MID 60S ALONG THE COAST AND MID TO UPPER 70S INLAND. AS THE
WEEKEND APPROACHES, A BETTER OPPORTUNITY FOR MUCH COOLER
TEMPERATURES AND PRECIPITATION PRESENTS ITSELF. /42
LONG TERM...FRIDAY THROUGH MONDAY
BY FRIDAY, ENSEMBLE
GUIDANCE CONVERGES ON A GENERALLY DRY PATTERN UNDER A NARROW,
SHORTWAVE RIDGE THAT WILL WARM THE CWA UP AGAIN BY A FEW DEGREES.
EXPECT DAYTIME HIGHS THE UPPER 70S TO LOW 80S INLAND AND UPPER
60S TO LOW 70S ALONG THE COAST. A LARGER-SCALE TROUGH BEGINS TO
DIG SOUTHEASTWARD FROM THE GULF OF ALASKA ON SATURDAY AND WILL
BRING AN INCREASING POTENTIAL FOR PRECIPITATION. AS THE
AFOREMENTIONED LOW MOVES EASTWARD, IT WILL DRAG A COLD FRONT
ACROSS THE REGION RESULTING IN PRECIPITATION CHANCES CLIMBING
ACROSS THE FORECAST AREA THROUGH SATURDAY. NW OREGON WILL SEE
POPS INCREASE TO 20-40% WITH HIGHER PROBABILITIES 50-70% FOR
SOUTHWEST WASHINGTON AND NEAR ASTORIA. SUNDAY AND INTO MONDAY,
TEMPERATURES WILL BE IN THE 70S INLAND AND LOW TO MID 60S ALONG
THE COAST. /42~HALL
AVIATION
HIGH PRESSURE AND LOW-LEVEL OFFSHORE FLOW WILL
MAINTAIN CLEAR SKIES ACROSS THE REGION THROUGHOUT THE TAF PERIOD,
EXCEPT AT THE COAST WHERE LIFR/IFR CIGS WILL MOST LIKELY DEVELOP
LATE TONIGHT (80% CHANCE AT KONP AND A 50-60% CHANCE AT KAST).
IN ADDITION, GUSTY EAST WINDS WILL CONTINUE TODAY BEFORE GRADUALLY
DECREASING IN STRENGTH THIS EVENING INTO TONIGHT. UNTIL THEN,
EXPECT WIND GUSTS UP TO 25-30 KT AT KTTD, 20 KT AT KHIO AND 20-25
KT AT KPDX. WINDS ARE GENERALLY LIGHT AND VARIABLE FROM KSLE TO
KEUG. NOTE THE STRONG EAST WINDS ARE ALSO RESULTING IN A PLUME OF
ASH AND DUST BLOWING WESTWARD OFF MT. ST. HELENS, HOWEVER THIS IS
NOT EXPECTED TO IMPACT ANY OF THE TERMINALS.
KPDX AND APPROACHES...CLEAR SKIES WILL CONTINUE THROUGHOUT THE TAF
PERIOD. GUSTY EAST WINDS UP TO 20-25 KT WILL CONTINUE TODAY BEFORE
GRADUALLY WEAKENING THIS EVENING INTO TONIGHT. -TK
MARINE
SOUTHERLY WINDS ARE EXPECTED TONIGHT AHEAD OF AN
INCOMING PACIFIC FRONT THAT WILL DECAY OVER THE COASTAL WATERS,
RESULTING IN MINIMAL IMPACTS. WINDS BECOME NORTHERLY ON WEDNESDAY
WHILE STRENGTHENING. GUSTS UP TO 25 KT ARE VERY LIKELY TO OCCUR
(90% CHANCE) LATE WEDNESDAY THROUGH THURSDAY, WITH GUSTS UP TO 30
KT POSSIBLE (50-70% CHANCE). SEAS WILL ALSO BUILD TO AROUND 10 FT
DURING THAT TIME. THEREFORE, HAVE ISSUED A SMALL CRAFT ADVISORY
FOR ALL MARINE ZONES FOR A COMBINATION OF WINDS AND SEAS,
INCLUDING THE COLUMBIA RIVER BAR. -TK
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 3 PM WEDNESDAY TO 5 AM PDT THURSDAY
FOR PZZ210.
SMALL CRAFT ADVISORY FROM 3 PM WEDNESDAY TO 5 PM PDT THURSDAY
FOR PZZ251>253-271>273.
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