418
FXUS66 KPQR 090542 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1042 PM PDT THU OCT 8 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
UNSEASONABLY WARM AND DRY WEATHER WILL GIVE WAY TO
COOLER TEMPERATURES AND CHANCES FOR LIGHT RAIN AS AN UPPER
TROUGH MOVES OVER THE REGION FRIDAY INTO SATURDAY. COOL NIGHTS
WILL BRING CHANCES FOR MORNING FROST IN RURAL VALLEYS AWAY FROM
URBAN CORES THIS WEEKEND INTO EARLY NEXT WEEK. DRY CONDITIONS
WITH SEASONABLE TEMPERATURES ARE EXPECTED SUNDAY AND MONDAY
BEFORE ANOTHER ROUND OF LIGHT RAIN IS POSSIBLE ON TUESDAY.
SHORT TERM...NOW THROUGH SATURDAY NIGHT
SUNNY SKIES UNDER
BROAD UPPER LEVEL RIDGING WILL MAINTAIN WARM AND DRY CONDITIONS
THROUGH THIS EVENING. A BIT OF A PATTERN CHANGE IS FORTHCOMING
AS THE WEATHER TRANSITIONS TOWARD MORE TYPICAL FALL-LIKE
CONDITIONS. WATER VAPOR SATELLITE IMAGERY REVEALS THE UPPER
LEVEL TROUGH CURRENTLY OVER THE GULF OF ALASKA THAT IS EXPECTED
TO DROP SOUTH INTO THE PACIFIC NORTHWEST ON FRIDAY. AS THIS
UPPER TROUGH APPROACHES, IT WILL PUSH A DECAYING COLD FRONT
ACROSS THE AREA LATER FRIDAY MORNING THROUGH THE AFTERNOON.
EXPECT CLOUDS COVER TO INCREASE TONIGHT WITH LIGHT RAIN PUSHING
ONTO THE SOUTH WA/NORTH OR COAST EARLY FRIDAY MORNING. BEST
CHANCE FOR RAIN ALONG THE I-5 CORRIDOR WILL BE LATER FRI MORNING
INTO THE AFTERNOON. RAIN ACCUMULATIONS WILL BE FAVORED ALONG
THE NORTH OR AND SOUTH WA COASTS AS WELL AS THE CASCADES AND
THEIR WESTERN SLOPES, WHILE AREAS ALONG THE CENTRAL OREGON COAST
AND WITHIN THE WILLAMETTE VALLEY ARE MORE LIKELY TO STAY DRIER.
AS THE TROUGH MOVES INLAND, A SECOND SHORTWAVE IMPULSE MOVING SOUTH
ON ITS WESTERN FLANK ON SATURDAY WILL SEE THE TROUGH ELONGATE AND
EVENTUALLY PINCH OFF INTO A CLOSED UPPER LOW WHICH WILL SETTLE SOUTH
OVER CALIFORNIA BY EARLY NEXT WEEK. THIS FEATURE WILL PRODUCE A
SECOND CHANCE OF LIGHT RAIN LATER FRIDAY NIGHT INTO SATURDAY AS
SCATTERED SHOWERS DEVELOP WITHIN THE COOLER AIR ALOFT. MEAN FORECAST
RAINFALL TOTALS DURING THIS PERIOD ARE 0.10-0.25 INCH NORTH OF
LINCOLN CITY AND IN THE CASCADES AND FOOTHILLS NORTH OF US-20, WITH
0.10 INCH OR LESS ELSEWHERE. THE CHANCES FOR 0.25 INCHES OF RAIN IN
48 HOURS REACH 40-60% IN THE WETTEST AREAS FROM TILLAMOOK COUNTY
NORTH ON THE COAST AND NORTH OF OR-22 IN THE CASCADES AND FOOTHILLS.
ELSEWHERE, THOSE CHANCES ARE 15-25% IN THE LOWER COLUMBIA AND
COWLITZ VALLEYS, AND 5-15% WITHIN THE WILLAMETTE VALLEY AND ALONG
THE COAST SOUTH OF PACIFIC CITY.
AS THE INITIAL FRONT MOVES INLAND FRIDAY THROUGH FRIDAY NIGHT,
PEAK GUSTS OUT OF THE WEST IN THE CASCADES, CENTRAL COLUMBIA
GORGE, AND HOOD RIVER VALLEY COULD REACH 35-45 MPH. BEHIND THE
BOUNDARY AS THE CORE OF COOLER AIR ALOFT MOVES OVERHEAD,
TEMPERATURES WILL QUICKLY FALL BACK TOWARD SEASONAL NORMS IN THE
UPPER 50S AND 60S FRIDAY AND SATURDAY. OVERNIGHT LOWS WILL
SIMILARLY TREND COOLER, ESPECIALLY SATURDAY NIGHT. ON FRIDAY
NIGHT, THERE IS HIGH CONFIDENCE THAT HIGHER ELEVATION PORTIONS
OF THE UPPER HOOD RIVER VALLEY NEAR DEE AND PARKDALE WILL SEE
TEMPERATURES IN THE MID 30S AND AN ELEVATED POTENTIAL FOR FROST. A
FROST ADVISORY IS IN EFFECT FOR PORTIONS OF THE UPPER HOOD RIVER
VALLEY COUNTY LATE FRIDAY NIGHT INTO SAT MORNING.
BY SATURDAY NIGHT, THE CHANCES FOR A TRUE FREEZE IN THE UPPER HOOD
RIVER VALLEY REACH 35-65% IN THOSE SAME AREAS. THERE ARE
ADDITIONALLY GREATER THAN 50% CHANCES FOR TEMPERATURES IN THE MID
30S AND FROST ON SATURDAY NIGHT IN THE CASCADE FOOTHILLS AND NORTH
OREGON COAST RANGE VALLEYS, AND 25-50% CHANCES IN THE SOUTHERN
WILLAMETTE VALLEY AND HIGHER ELEVATION PORTIONS OF CLARK AND COWLITZ
COUNTY LOWLANDS IN SOUTHWESTERN WASHINGTON.
FROST ADVISORIES AND/OR FREEZE WATCHES MAY THEREFORE BE
NEEDED, AND THOSE WITH AGRICULTURAL INTERESTS SHOULD CONTINUE
TO MONITOR THE FORECAST. DH/36
LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT
ENSEMBLE
GUIDANCE IS IN GOOD AGREEMENT THAT THE ELONGATED UPPER TROUGH
DROPS SOUTH OVER CALIFORNIA ON SUNDAY AND EVENTUALLY SPLITS INTO
A CUTOFF UPPER LOW EARLY NEXT WEEK. WEAK UPPER LEVEL RIDGING OF
THE NE PACIFIC WILL NUDGE BACK OVER THE REGION, LEADING TO DRY
AND MORE SEASONABLY WARM TEMPERATURES INTO THE MID TO UPPER 60S.
SUNDAY MORNING WILL FEATURE A NEAR-REPEAT OF SATURDAY MORNING,
IF NOT COOLER UNDER MORE CLEAR SKIES, WITH WIDESPREAD CHANCES
FOR FROST IN SHELTERED VALLEYS AWAY FROM URBAN AREAS AND CHANCES
FOR A FREEZE WITHIN THE UPPER HOOD RIVER VALLEY. THERE IS
INCREASING CONSENSUS AMONG LONG-RANGE ENSEMBLE MEMBERS IN
ADDITIONAL UPPER-LEVEL TROUGHING MOVING INTO THE REGION TUESDAY
INTO WEDNESDAY. AT THIS POINT, LOW TO MODERATE (35- 55%) CHANCES
FOR RAIN ARE ASSESSED DURING THIS PERIOD UNTIL CONFIDENCE IN
THE EVOLUTION OF THIS FEATURE INCREASES. DH/36
AVIATION...THROUGH 06Z SATURDAY
VFR CONDITIONS PERSIST INLAND
WHILE MARINE STRATUS HAS MOVED IN ALONG THE ENTIRE COAST,
SUPPORTING MVFR OR LOWER CIGS. UPPER LEVEL CLOUDS ARE STREAMING IN
ALONG WESTERLY FLOW AHEAD OF AN APPROACHING TROUGH AND FRONTAL
SYSTEM. THE TROUGH IS EXPECTED TO BRING RAIN TO KAST AROUND 12Z
AND THEN INTERIOR LOWLAND TERMINALS AROUND 15-20Z AS THE FRONT
MOVES SOUTHWARD (KPDX: AROUND 15Z, KEUG: AROUND 19Z). ADDITIONALLY,
THIS TROUGH WILL BRING A 40-70% CHANCE OF MVFR CIGS.
LIGHT NORTH TO NORTHWEST WINDS AROUND 5 KT WILL EASE OVERNIGHT.
WINDS INLAND ARE EXPECTED TO INCREASE AHEAD OF THE FRONT,
INITIALLY OUT OF THE SOUTH AROUND 5 KT BUT WILL QUICKLY TURN
WESTERLY WITH THE PASSAGE OF THE FRONT ALONG WITH INCREASING TO
AROUND 10 KT AND GUSTS. WINDS ALONG THE COAST WILL REMAIN
NORTHWESTERLY THROUGH THE PERIOD BUT WILL INCREASE BEHIND THE
FRONT TO 10-15 KT WITH GUSTS AROUND 20 KT.
KPDX AND APPROACHES...VFR WITH HIGH CLOUD COVER THROUGH MOST OF
THE PERIOD. A TROUGH APPROACHING WILL BRING A CHANCE OF RAIN TO
AROUND 16Z FRI AND A 40-60% CHANCE OF MVFR CIGS. ADDITIONALLY,
WINDS WILL LIKELY INCREASE TOMORROW AFTERNOON, TO AROUND 8 TO 10
KT. -19
MARINE
HIGH PRESSURE AT THE SURFACE OVER THE NORTHEASTERN
PACIFIC TODAY CONTINUES TO BRING AFTERNOON/EVENING WIND GUSTS OF
20-25 KT. AS A RESULT, SMALL CRAFT ADVISORIES FOR THE WATERS
SOUTH OF CAPE FALCON REMAIN IN EFFECT UNTIL 11 PM TONIGHT.
ANTICIPATE LARGELY WIND-DRIVEN SEAS OF 6-9 FT WITH AN UNDERLYING
WEST-NORTHWEST SWELL DURING THE ADVISORIES. WHILE WEAKENING
HIGH PRESSURE ALOFT WOULD CONTINUE TO SUPPORT AREAS OF FOG IN
THE MORNING HOURS TOMORROW, AN APPROACHING WEATHER SYSTEM THAT
WILL BRING RAIN AND WIND WILL LIKELY INHIBIT FOG FROM BECOMING
DENSE.
THIS WEATHER SYSTEM ON FRIDAY AND THROUGH THE WEEKEND, WHICH IS A
TROUGH OVER THE GULF OF ALASKA PUSHING SOUTHWARD, WILL GENERATE A
NORTHWEST SWELL IN ADDITION TO THE ARRIVAL OF A FRONTAL BOUNDARY.
WINDS OUT OF THE NORTHWEST ASSOCIATED WITH THE FRONTAL BOUNDARY
WILL INCREASE TO AROUND 20 TO 25 KT ON FRIDAY, ESPECIALLY NORTH
OF CAPE FALCON, WHILE SEAS PEAK AT 8-12 FT FRIDAY EVENING INTO
SATURDAY. BY SUNDAY, WINDS EASE AND VEER OUT OF THE NORTH TO
NORTH-NORTHEAST WHILE SEAS FALL BACK TO 5-7 FT THROUGH EARLY NEXT
WEEK. ~12/36
PQR WATCHES/WARNINGS/ADVISORIES
OR...FROST ADVISORY FROM MIDNIGHT FRIDAY NIGHT TO 9 AM PDT SATURDAY
FOR ORZ121.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 11 AM TO 6 PM PDT FRIDAY FOR PZZ210.
SMALL CRAFT ADVISORY FROM 8 AM TO 2 PM PDT FRIDAY FOR PZZ251.
SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR PZZ252-
253-272-273.
SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM PDT FRIDAY FOR PZZ271.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page