621
FXUS66 KPQR 100547
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1047 PM PDT FRI OCT 9 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
A WEAK COLD FRONT WILL PROGRESS EASTWARD OVER THE
CASCADES THIS EVENING, BRINGING AN END TO ANY LINGERING RAIN
SHOWERS FOR MOST LOCATIONS. CHANCES FOR LIGHT SHOWERS INCREASE
SLIGHTLY ON SATURDAY, HOWEVER MOST LOCATIONS WILL STAY DRY
THROUGH THE DAY WITH NOTICEABLY COOLER TEMPERATURES. COOL NIGHTS
WILL BRING CHANCES FOR MORNING FROST IN RURAL VALLEYS AWAY FROM
URBAN CORES THIS WEEKEND INTO EARLY NEXT WEEK. DRY CONDITIONS
ARE EXPECTED SUNDAY THROUGH AT LEAST MONDAY, WITH CHANCES FOR
LIGHT RAIN INCREASING SLIGHTLY LATE TUESDAY. TEMPERATURES TREND
A BIT WARMER LATE IN THE WEEK WITH DRY WEATHER AS UPPER-LEVEL
RIDGING AMPLIFIES OVER THE REGION.
SHORT TERM...NOW THROUGH SUNDAY NIGHT
RADAR, SATELLITE, AND
SURFACE WEATHER OBSERVATIONS FROM EARLY FRIDAY AFTERNOON
DEPICTED A NARROW BAND OF RAIN OCCURRING ALONG A SOUTHWEST-
NORTHEAST ORIENTED COLD FRONT DRAPED OVER THE NORTHERN
WILLAMETTE VALLEY, PORTLAND-VANCOUVER METRO, COLUMBIA RIVER
GORGE, AND SOUTH WA/NORTH OR CASCADES. BEHIND THIS WEAK FRONT,
ISOLATED LIGHT SHOWERS AND SPRINKLES WERE BEING OBSERVED. AS
THIS FRONT CONTINUES PROGRESSING EASTWARDS OVER THE CASCADES
THIS EVENING, RAIN WILL QUICKLY COME TO AN END ASIDE FROM A FEW
STRAY SHOWERS. OBSERVED RAIN TOTALS ARE GENERALLY TOPPING OUT
BETWEEN A TRACE AND 0.10 INCHES, EXCEPT FOR SLIGHTLY HIGHER
AMOUNTS AT THE COAST AND OVER HIGHER TERRAIN. WHILE THIS ISN'T
VERY MUCH RAIN, IT AT LEAST BREAKS OUR IMPRESSIVE 13-DAY DRY
STREAK.
OBSERVED WIND GUSTS WITH THIS FRONTAL PASSAGE HAVE GENERALLY PEAKED
BETWEEN 15-30 MPH, RESULTING IN LITTLE TO NO IMPACTS. HOWEVER,
WESTERLY WINDS IN THE CENTRAL COLUMBIA RIVER GORGE AND ON EXPOSED
RIDGETOPS ADJACENT TO THE GORGE ARE NOT EXPECTED TO PEAK UNTIL LATER
THIS EVENING IMMEDIATELY BEHIND THE FRONTAL PASSAGE. THESE AREAS CAN
EXPECT MAX GUSTS BETWEEN 25-45 MPH, STRONGEST ON EXPOSED RIDGETOPS.
EVEN THEN, WIND IMPACTS SHOULD BE MINOR.
ALTHOUGH RAIN WILL QUICKLY END THIS EVENING IN THE WAKE OF THE COLD
FRONT, CHANCES FOR RAIN WILL INCREASE AGAIN LATE TONIGHT INTO
SATURDAY. THIS IS IN RESPONSE TO A CLOSED UPPER-LEVEL LOW THAT IS SET
TO MOVE SOUTHWARD OVER THE REGION ON SATURDAY, BRINGING WRAP-AROUND
MOISTURE ON THE RELATIVELY COOLER BACKSIDE OF THE LOW OVER WESTERN
WA/OR. GIVEN THE LIGHT AND SHOWERY NATURE OF PRECIPITATION ON
SATURDAY, RAIN TOTALS WILL BE EVEN LIGHTER THAN FRIDAY FOR MOST
LOCATIONS (70-90% CHANCE RAIN AMOUNTS WILL BE LESS THAN 0.10"). IN
FACT, MANY LOCATIONS WILL SEE LITTLE TO NO RAIN AT ALL ON SATURDAY,
ESPECIALLY DOWNWIND OF HIGHER TERRAIN WHERE RAIN-SHADOWING WILL BE
MOST PRONOUNCED.
IT IS ALSO WORTH NOTING THAT CLEARING SKIES OVER THE UPPER HOOD RIVER
VALLEY TONIGHT MAY SUPPORT LOWS DIPPING INTO THE 30S DEPENDING ON HOW
QUICKLY WESTERLY WINDS COME TO AN END. IF WINDS BECOME CALM EARLY IN
THE NIGHT, LOWS COULD EASILY DROP TO 33-36 DEGREES. IF WINDS HANG ON
UNTIL SUNRISE, LOWS WOULD STRUGGLE TO FALL BELOW 40 DEGREES. THE
CURRENT FORECAST SUGGESTS WINDS WILL BECOME LIGHTER BY 4-5 AM, WHICH
WOULD ALLOW TEMPERATURES TO QUICKLY PLUMMET THEREAFTER UNTIL SUNRISE,
WITH AREAS OF FROST LIKELY FORMING SHORTLY BEFORE SUNRISE IN
WIND-SHELTERED AREAS WHERE LOWS BELOW 37 DEGREES ARE POSSIBLE. DEE
AND PARKDALE HAVE THE BEST CHANCE FOR FROST DEVELOPMENT BY SUNRISE ON
SATURDAY (80-90% CHANCE), AND THESE AREAS HAVE A FROST ADVISORY IN
EFFECT TO COVER THIS THREAT. ODELL MAY SEE PATCHY FROST AS WELL,
HOWEVER CHANCES ARE RELATIVELY LOWER AT AROUND 35-45%.
CHANCES FOR MORE WIDESPREAD AND IMPACTFUL MORNING FROST INCREASE
CONSIDERABLY SATURDAY NIGHT INTO SUNDAY MORNING GIVEN CLEAR SKIES AND
CALM WINDS WILL BE IN PLACE THROUGH THE NIGHT. THERE IS HIGH
CONFIDENCE FOR FROST AND MORNING LOWS BETWEEN 33-36 DEGREES OVER THE
UPPER HOOD RIVER VALLEY, CASCADE FOOTHILLS, NORTH OREGON COAST RANGE
VALLEYS, BATTLE GROUND/BRUSH PRAIRIE AREA, AND PORTIONS OF THE
CENTRAL/SOUTHERN WILLAMETTE VALLEY TO THE EAST OF THE I-5 CORRIDOR
NEAR THE FOOTHILLS (E.G. LEBANON, SCIO, ALBANY, HALSEY, BROWNSVILLE,
SWEET HOME, MARCOLA, MOHAWK, JASPER). SUB-FREEZING TEMPERATURES LESS
THAN 32 DEGREES ARE LIKELY IN DEE AND PARKDALE (70-90% CHANCE).
THEREFORE, VARIOUS FROST ADVISORIES ARE CURRENTLY IN EFFECT WHERE
CONFIDENCE IN FROST FORMATION IS HIGHEST. ANYONE GROWING OUTDOOR
PLANTS THAT ARE SUSCEPTIBLE TO FROST DAMAGE SHOULD COVER PLANTS OR
MOVE PLANTS INDOORS IF POSSIBLE. -23
LONG TERM...MONDAY THROUGH THURSDAY NIGHT
THE LONG TERM
FORECAST IS HIGHLIGHTED BY SEASONABLE TEMPERATURES MONDAY
THROUGH WEDNESDAY WITH TEMPERATURES BECOMING WARMER AND ABOVE
AVERAGE LATE IN THE WEEK AS AN UPPER-LEVEL RIDGE OVER THE FAR
NORTHEAST PACIFIC EARLY IN THE WEEK BECOMES MORE AMPLIFIED AND
MOVES OVER THE U.S. WEST COAST. THIS SET-UP WILL BRING MAINLY
DRY CONDITIONS MONDAY THROUGH THURSDAY NIGHT, WITH ONE POTENTIAL
EXCEPTION LATE TUESDAY INTO WEDNESDAY MORNING WHEN CHANCES FOR
LIGHT RAIN INCREASE TO 10-30% AS A WEAK COLD FRONT OVER THE
COASTAL WATERS ATTEMPTS PUSHING INLAND. EVEN IF THIS FRONT IS
ABLE TO MOVE INLAND, IT WOULD BE DECAYING, WHICH SUGGESTS RAIN
AMOUNTS WOULD LIKELY BE VERY LIGHT (A TRACE TO 0.10 INCHES, IF
ANY AT ALL). CURRENTLY AROUND 50-70% OF THE TOTAL ENSEMBLE SPACE
FROM THE 00Z/OCT. 9 ITERATION OF THE ENS/GEFS/GEPS SHOWS NO
RAIN AT ALL TUESDAY INTO WEDNESDAY, WITH RAIN MOST FAVORED OVER
SOUTHWEST WA, COASTAL AREAS, AND HIGHER TERRAIN. NO IMPACTS ARE
EXPECTED WITH THIS FRONT.
FOR TEMPERATURES, EXPECT CHILLY MORNING LOWS TO CONTINUE MONDAY
MORNING AND TUESDAY MORNING, ESPECIALLY IN RURAL AREAS AND SHELTERED
VALLEYS WHERE LOWS IN THE MID 30S WILL SUPPORT FROST. LOCATIONS THAT
CURRENTLY HAVE FROST ADVISORIES IN EFFECT FOR SATURDAY NIGHT/SUNDAY
MORNING ARE THE AREAS WITH THE HIGHEST CHANCES FOR CONTINUED FROSTY
MORNINGS WITH LOWS BELOW 37 DEGREES ON MONDAY AND TUESDAY (40-65%
CHANCE, EXCEPT 80-90% IN THE UPPER HOOD RIVER VALLEY). AFTERNOON
TEMPERATURES WILL BE MUCH MORE MILD, WITH HIGHS IN THE MID TO UPPER
60S OVER THE LOWLANDS MONDAY THROUGH WEDNESDAY, WARMING INTO THE
UPPER 60S TO MID 70S ON THURSDAY. -23
AVIATION...THROUGH 06Z SUNDAY
MAINLY VFR CONDITIONS WITH
SCATTERED LOW AND MID LEVEL CLOUDS STREAMING IN ALONG NORTHWEST
FLOW. SCATTERED RAIN SHOWERS HAVE POPPED UP AND WILL CONTINUE TO
MOVE ACROSS THE AREA IN THE POST FRONTAL ENVIRONMENT. GUIDANCE
SUGGESTS LOW STRATUS REMAINS AWAY FROM THE TERMINALS WITH LOW
(10-20%) CHANCES FOR MVFR CIGS AT ANY GIVEN TERMINAL. STRATUS
ALONG THE WESTERN SLOPES OF THE CASCADES AND COAST RANGE ARE
POSSIBLE. BRIEF SUB-VFR CONDITIONS ARE POSSIBLE IF ANY LIGHT
SHOWER PASSES DIRECTLY OVER A TERMINAL. LIGHT NORTHWEST WINDS LESS
THAN 5 KT OVERNIGHT BECOMING SOUTHERLY INLAND LATE SATURDAY
MORNING AND STAYING NORTHWEST ALONG THE COAST.
KPDX AND APPROACHES...VFR CONDITIONS THROUGH THE PERIOD. THERE IS
A 10-20% CHANCE FOR LIGHT RAIN SHOWERS THROUGH SATURDAY AFTERNOON.
ANY SHOWER THAT PASSES DIRECTLY OVER THE TERMINAL MAY BRING
SUB-VFR CONDITIONS. LIGHT WEST WINDS SHIFT SOUTHERLY DURING THE
DAY. -19
MARINE
A FRONTAL SYSTEM HAS MOVED THROUGH MOST OF THE WATERS
TODAY, WITH THE REMAINDER OF THE FRONT MOVING THROUGH THE
WATERS SOUTH OF CAPE FOULWEATHER AS OF 2 PM. BREEZY
NORTHWESTERLY WINDS WITH GUSTS UP TO 25 KT CONTINUE TONIGHT INTO
SATURDAY MORNING OVER THE WATERS NORTH OF CAPE FALCON. WITH
THIS FRONTAL SYSTEM BRINGING A NORTHWESTERLY SWELL, SEAS WILL
BUILD TO 9-12 FT AT 9-10 SECONDS FROM NORTH TO SOUTH OVER MOST
OF THE WATERS THIS EVENING THROUGH SATURDAY AFTERNOON.
AS A RESULT OF SEAS BUILDING AND BECOMING STEEP AND CHOPPY, A
HAZARDOUS SEAS WARNING REMAINS IN EFFECT FOR THE OUTER WATERS
NORTH OF CAPE FALCON UNTIL 5 AM SATURDAY. ADDITIONALLY, SMALL
CRAFT ADVISORIES REMAIN IN EFFECT OVER ALL OF THE WATERS
(INCLUDING THE COLUMBIA BAR) EXCEPT FOR THE INNER WATERS SOUTH OF
CAPE FOULWEATHER AND OUTER WATERS NORTH OF CAPE FALCON UNTIL 2 PM
SATURDAY DUE TO STEEP AND CHOPPY SEAS OF 8-10 FT AT 9-10 SECONDS.
BY SUNDAY, WINDS WEAKEN AND VEER OUT OF THE NORTH/NORTHEAST WHILE
SEAS FALL BACK TO 6-8 FT THROUGH EARLY NEXT WEEK. ~12/10
PQR WATCHES/WARNINGS/ADVISORIES
OR...FROST ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 9 AM PDT SUNDAY
FOR ORZ104-106-113-117-121-123>125.
FROST ADVISORY UNTIL 9 AM PDT SATURDAY FOR ORZ121.
WA...FROST ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 9 AM PDT SUNDAY
FOR WAZ205-208.
PZ...SMALL CRAFT ADVISORY UNTIL 2 PM PDT SATURDAY FOR PZZ210-251-
252-272-273.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT SATURDAY FOR PZZ271.
SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM PDT SATURDAY FOR PZZ271.
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