354
FXUS66 KPQR 170458 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
958 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
THE WARM AND DRY
CONDITIONS TODAY LED TO RECORD BREAKING TEMPERATURES AND GUSTY
EASTERLY WINDS. BELOW, A LIST OF THE RECORDS ARE POSTED. 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, THERE IS A LOW
PROBABILITY PRECIPITATION REACHING THE COAST. HOWEVER THE COOLER
AIR WILL RESULT IN DAYTIME HIGHS 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. -MUESSLE/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 INLAND WILL MAINTAIN LARGELY CLEAR SKIES
AND LIGHT AND VARIABLE WINDS OF 5 KT OR LESS ACROSS WILLAMETTE
VALLEY TERMINALS TONIGHT. ALONG THE COAST, MARINE STRATUS WILL
SUPPORT IFR CIGS WITH HIGH CONFIDENCE AT KONP (70-80% LIKELIHOOD)
AND MODERATE CONFIDENCE (50-60%) AT KAST. CONFIDENCE IN PERSISTENT
RESTRICTED VIS WITHIN MIST IS LOW AT THE COAST, BUT INTERMITTENT
VIS OF 3SM OR LESS IS POSSIBLE (20-50% CHANCES). LOW STRATUS LOOKS
TO BREAK OUT TO MVFR CIGS AT KAST AND VFR CONDITIONS AT KONP BY
18-20Z WED. NORTH TO NORTHWEST WINDS RISE TO 5-10 KT INLAND AND
10-15 KT WITH GUSTS OF 20-25 KT ALONG THE COAST AFTER 17-20Z WED.
EARLIER GUSTY EAST WINDS PRODUCED A PLUME OF RESUSPENDED ASH TO
THE WEST AND NORTHWEST OF MOUNT ST HELENS, HOWEVER THIS IN NOT
EXPECTED TO IMPACT ANY TERMINALS.
KPDX AND APPROACHES...LARGELY CLEAR SKIES PERSIST THROUGH THE
PERIOD. EAST WINDS AT 5-10 KT WILL EASE BY 09-10Z WED, WITH LIGHT
AND VARIABLE WINDS THEN CONTINUING THROUGH TONIGHT. DIURNAL WINDS
RISE BY 18Z WED TO AROUND 10 KT OUT OF THE NORTHWEST. -PICARD
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.
CLIMATE
RECORD HIGH TEMPERATURES SET ACROSS NORTHWESTERN
OREGON.
ASTORIA - HIGH OF 89 DEGREES BREAKING THE OLD RECORD OF 85
DEGREES SET IN 1994.
EUGENE - HIGH OF 93 DEGREES BREAKING THE OLD RECORD OF 91
DEGREES SET IN 1994.
SALEM - HIGH OF 93 DEGREES TYING THE RECORD SET IN 1929 AND
1994.
ALL OBSERVATIONS ARE CONSIDERED PRELIMINARY.
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.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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