142
FXUS66 KPQR 161237 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
537 AM PDT FRI OCT 16 2026
UPDATED AVIATION AND MARINE DISCUSSIONS.
SYNOPSIS
CONDITIONS REMAIN DRY WITH WELL ABOVE AVERAGE
TEMPERATURES. EASTERLY WINDS WILL GRADUALLY WEAKEN AS A TROUGH
APPROACHES. A WEAK COLD FRONT WILL BRING CHANCES FOR LIGHT RAIN
LATE TONIGHT INTO SATURDAY MORNING, BEFORE HIGH PRESSURE RETURNS
DRY WEATHER SATURDAY NIGHT INTO SUNDAY. THE NEXT CHANCES FOR
RAIN ARE MONDAY INTO EARLY TUESDAY WITH AN APPROACHING LOW
PRESSURE SYSTEM, ALTHOUGH GUIDANCE CONTINUES TO TREND DRIER.
SHORT TERM...NOW THROUGH SATURDAY NIGHT
UPPER LEVEL RIDGING
WILL CONTINUE SHIFTING EAST AS TROUGHING OVER THE NORTHEAST
PACIFIC AND ALASKA PROGRESSES EASTWARD. CONDITIONS REMAIN DRY
ACROSS THE REGION WITH ANOTHER DAY OF ABOVE NORMAL TEMPERATURES.
HIGHS IN THE MID TO UPPER 70S ACROSS THE INTERIOR LOWLANDS,
10-15 DEGREES ABOVE THE NORMAL LOW TO MID 60S. HIGHS ALONG THE
COAST WILL BE MUCH CLOSER TO NORMAL AS THE OFFSHORE PRESSURE
GRADIENT CONTINUES TO WEAKEN, ALLOWING WESTERLY ONSHORE FLOW TO
RETURN AND MARINE STRATUS TO PUSH INTO THE COAST. HIGHS EXPECTED
TO TOP OUT IN THE LOW TO MID 60S. HIGH LEVEL CLOUDS WILL ALSO
INCREASE THROUGH THE DAY AS THE UPPER LEVEL TROUGH PROGRESSES.
THE OFFSHORE PRESSURE GRADIENT BETWEEN TROUTDALE AND THE DALLES
WILL CONTINUE TO WEAKEN THROUGH THE DAY WHICH WILL GRADUALLY
DECREASE EASTERLY WINDS TO LESS THAN 10 MPH BY THE AFTERNOON.
AN EMBEDDED SHORTWAVE TROUGH PASSING TO THE NORTH WILL GLANCE
THE REGION, SENDING A COLD FRONT THROUGH THE AREA TONIGHT AND
INTO SATURDAY MORNING. THIS WILL BRING MODERATE TO LOW CHANCES
OF LIGHT RAIN TO NORTHERN PORTIONS OF THE FORECAST AREA FOR
SATURDAY MORNING. MEAN QPF VALUES RANGE FROM A TRACE TO 0.10
INCH, GENERALLY NORTH OF LINCOLN CITY AT THE COAST AND FROM THE
PORTLAND METRO AREA NORTHWARD, WITH HIGHEST CHANCES FOR RAIN IN
THE SOUTHWEST WA CASCADES. CONDITIONS EXPECTED TO DRY OUT BY THE
AFTERNOON WITH NORTHERLY WINDS BEHIND THE FRONT. HIGHS WILL BE
CLOSER TO NORMAL, TOPPING OUT IN THE MID TO UPPER 60S ACROSS THE
INTERIOR VALLEYS. WILL NEED TO KEEP AN EYE ON SATURDAY NIGHT AS
CLOUDS CLEAR AND TEMPERATURES DROP INTO THE 30S. OUTSIDE OF THE
CASCADES, THE COOLEST TEMPERATURES ARE EXPECTED IN THE UPPER
HOOD RIVER VALLEY. -19/DH
LONG TERM...SUNDAY THROUGH THURSDAY
DRY WEATHER EXPECTED ON
SUNDAY AS FLOW ALOFT BECOMES MORE ZONAL WITH THE PASSAGE OF THE
SHORTWAVE TROUGH. HIGHS VERY SIMILAR TO SATURDAY PEAKING IN THE
MID 60S FOR MOST INTERIOR LOWLANDS AND MID 50S TO LOW 60S ALONG
THE COAST. SUNDAY NIGHT INTO MONDAY MORNING WILL BRING ANOTHER
CHANCE FOR FROST IN THE UPPER HOOD RIVER VALLEY AND THE SOUTHERN
WILLAMETTE VALLEY AS LOWS COULD DROP INTO THE MID TO UPPER 30S.
CLUSTER ANALYSIS CONTINUES TO DEPICT A TROUGH IMPACTING THE
REGION MONDAY AND TUESDAY BUT TRENDS HAVE THE TROUGH TAKING A
MORE SOUTHEAST TRAJECTORY AND JUST GLANCING NW OR AND SW WA.
APPROXIMATELY 40% OF ENSEMBLE MEMBERS HAVE LIGHT QPF FOR THE
PORTLAND AREA WHILE 60% OF MEMBERS HAVE LIGHT QPF AROUND
NEWPORT. MODELS CONTINUE TO TRACK THIS TROUGH MORE TOWARDS
NORTHERN CALIFORNIA, LIMITING ANY DECENT RAINFALL ACROSS THE
FORECAST AREA. CHANCES FOR 24-HOUR RAINFALL TOTALS EXCEEDING
0.25 INCHES BETWEEN 5 AM MONDAY TO 5 AM TUESDAY HAVE DROPPED TO
10-15% ALONG THE COAST AND COAST RANGE, SOUTHERN WILLAMETTE
VALLEY, AND THE OR CASCADE FOOTHILLS.
BY WEDNESDAY, ENSEMBLES SHOW THE UPPER TROUGH SWINGING INTO
CENTRAL CALIFORNIA, WHILE WEAK HIGH PRESSURE SHIFTS OVER THE
PACIFIC NORTHWEST, FAVORING PREDOMINATELY DRY CONDITIONS. AT THE
SAME TIME, IT DOES APPEAR THAT ANOTHER UPPER-LEVEL TROUGH WILL
BEGIN TO APPROACH BRITISH COLUMBIA AND POTENTIALLY MAKE ITS WAY
DOWN INTO THE PACIFIC NORTHWEST LATE NEXT WEEK, RETURNING
CHANCES FOR PRECIPITATION. -19/DH
AVIATION...THROUGH 12Z SATURDAY
MAINLY VFR CONDITIONS EXPECTED
THOUGH A FEW PATCHES OF FOG HAVE DEVELOPED UNDER MOSTLY CLEAR
SKIES. INTERMITTENT FOG HAS BEEN REPORTED BY KONP AND KEUG BUT
MAY NOT STICK AROUND LONG. MARINE STRATUS IS EXPECTED TO DEVELOP
THIS AFTERNOON AS A TROUGH APPROACHES AND WINDS TURN MORE
WESTERLY. CONDITIONS ALONG THE COAST START TO DETERIORATE WITH
PROBABILITIES FOR MVFR/IFR CIGS INCREASING TO AROUND 50% AT 20Z
AND FURTHER TO 70-80% AFTER 6Z SATURDAY. THIS DISTURBANCE WILL
ALSO BRING LIGHT RAIN AFTER 6Z, MAINLY AROUND KAST.
EASTERLY WINDS REMAIN STRONG THROUGH THE WESTERN COLUMBIA RIVER
GORGE AND INTO THE EASTERN METRO. KTTD IS STILL REGISTERING WIND
GUSTS OVER 30 KT BUT SHOULD GRADUALLY TREND LOWER THROUGH THE DAY
AS THE PRESSURE GRADIENT WEAKENS. WINDS ELSEWHERE WILL BECOME
NORTHWESTERLY AROUND 5 KT THIS AFTERNOON.
KPDX AND APPROACHES...VFR WITH CLEAR SKIES THROUGH THE TAF PERIOD.
LIGHT WINDS BECOMING NORTHWESTERLY LESS THAN 5 KT. -19
MARINE
BENIGN MARINE CONDITIONS CONTINUE. NORTHWEST WINDS TURN
SOUTHERLY THIS AFTERNOON INTO THE EVENING AS A WEAK FRONT PASSES
THROUGH. WINDS TURN BACK TO THE NORTHWEST ON SATURDAY BEHIND THE
FRONT. SEAS REMAIN AROUND 4-7 FT AT 10-12 SECONDS THROUGH EARLY
SATURDAY MORNING.
A STEEPER NORTHWESTERLY SWELL ARRIVES THIS WEEKEND, BUILDING SEAS
TO 7-9 FT BY SATURDAY EVENING AND 10-13 FT EARLY NEXT WEEK.
UNCERTAINTY REMAINS ON HOW HIGH SEAS WILL RISE EARLY NEXT WEEK DUE
TO UNCERTAINTY ON THE TRACK OF THE LOW PRESSURE SYSTEM ASSOCIATED
WITH THE SWELL. THERE IS A 15-30% CHANCE FOR SEAS EXCEEDING 15 FT
ON MONDAY, WITH THE HIGHEST CHANCES BEYOND 30-40 NM. WILL ALSO
NOTE THAT THE LONG PERIODS FROM THE SWELLS WILL RESULT IN A
MODERATE SNEAKER WAVE THREAT FRIDAY INTO EARLY NEXT WEEK. CAUTION
SHOULD BE USED WHEN IN OR NEAR THE WATER. -19/03
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
WWW.WEATHER.GOV/PORTLAND
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