004
FXUS66 KPQR 222221
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
321 PM PDT WED OCT 22 2025
SYNOPSIS
ACTIVE AND WET WEATHER BEGINS ACROSS THE REGION
TODAY AS REPEATED FRONTAL SYSTEMS BRING ROUNDS OF PRECIPITATION
TO THE NORTHWEST. FOLLOWING A DRIER DAY ON THURSDAY, A MODERATE
ATMOSPHERIC RIVER WILL BRING PERIODS OF MODERATE TO HEAVY RAIN
FRIDAY THROUGH THE WEEKEND, AND GUSTY SOUTH WINDS MOSTLY ON
SATURDAY. BREEZY AND WET WEATHER IS OTHERWISE LARGELY EXPECTED
THROUGH MUCH OF THE WEEK.
SHORT TERM...NOW THROUGH FRIDAY NIGHT
PERSISTENT UPPER-LEVEL
TROUGHING OVER THE GULF OF ALASKA WILL SEE REPEATED SHORTWAVE
IMPULSES TRACK OVER THE PACIFIC NORTHWEST OVER THE NEXT WEEK.
AN INITIAL WEAK FRONTAL SYSTEM MOVING ONSHORE THROUGH TONIGHT
WILL SEE LIGHT RAIN SHOWERS, MOST LIKELY ALONG THE COAST AND IN
AREAS OF HIGHER TERRAIN NORTH OF US 26 WHERE EXPECTED TOTALS
REMAIN ONLY 0.05-0.1" OR LESS. CHANCES FOR 0.25" OF RAIN OVER
THE NEXT 24 HOURS REMAIN AT 5-15% IN THOSE AREAS, AND MUCH LESS
ELSEWHERE. AS THIS INITIAL WAVE EXITS EASTWARD BY THURSDAY
MORNING, A BRIEF DRYING TREND WILL RETURN TO THE REGION AS
TRANSIENT SHORTWAVE RIDGING PASSES OVERHEAD ON THURSDAY. HIGH
TEMPERATURES WILL REMAIN SOME 5 DEGREES OR SO ABOVE NORMAL,
REACHING THE UPPER 50S TO UPPER 60S ACROSS THE REGION.
HEIGHTS ALOFT WILL BEGIN TO FALL THURSDAY NIGHT AND CONTINUE
THROUGH FRIDAY AS A MUCH MORE POTENT COLD FRONTAL BOUNDARY
APPROACHES THE COAST. THIS MODERATE ATMOSPHERIC RIVER WILL MOVE
ACROSS THE REGION IN ABOUT 24-30 HOURS, BRINGING PERIODS OF
MODERATE TO LOCALLY HEAVY RAINFALL AND BREEZY SOUTH WINDS.
GUSTS ARE MOST LIKELY TO REACH 25-30 MPH INLAND AND 40-45 MPH
ALONG THE COAST FRIDAY AFTERNOON. THERE REMAINS AN OUTSIDE
CHANCE, 5-10% OR LESS, THAT MORE IMPACTFUL WIND GUSTS OF 45 MPH
MAY OCCUR ALONG THE WILLAMETTE VALLEY AND 55-60 MPH ALONG THE
COAST, WHICH WOULD HAVE THE POTENTIAL TO PRODUCE WIND DAMAGE AND
POWER OUTAGES, ESPECIALLY GIVEN PLENTY OF LEAVES ON TREES TO
INCREASE WIND DRAG.
THERE IS VERY HIGH CONFIDENCE, GREATER THAN 90-95%, OF RAINFALL
TOTALS EXCEEDING 0.5" ACROSS AREAS WEST OF THE CASCADE CREST
THROUGH FRIDAY NIGHT, WITH EXPECTED RAIN AMOUNTS OF 1-1.25"
ALONG THE I-5 CORRIDOR, 1.5-2.5" ALONG THE COAST AND IN THE
COAST RANGE, AND 1-2" IN THE CASCADES. CHANCES TO SEE 2" OF RAIN
ARE 15-25% ALONG THE I-5 CORRIDOR, AND 40-80% TO THE EAST AND
WEST, WITH THE HIGHEST LIKELIHOOD ON THE WESTERN COAST RANGE
SLOPES. BRIEFLY HEAVY RAIN RATES MAY PRODUCE NUISANCE FLOODING,
MOST LIKELY IN URBAN AREAS WITH POOR DRAINAGE AND WHERE LEAF
CLUTTER IS ABLE TO CLOG DRAINS, BUT LUCKILY, AREA RIVERS REMAIN
LOW THIS EARLY IN THE WET SEASON AND SHOULD BE ABLE TO HANDLE
THESE TOTALS WITHOUT ANY WIDESPREAD CONCERNS FOR FLOODING.
LONG TERM...SATURDAY THROUGH WEDNESDAY
THE MORE ACTIVE
WEATHER PATTERN CONTINUES THROUGH THIS WEEKEND INTO EARLY NEXT
WEEK AS ADDITIONAL IMPULSES MOVE ACROSS THE REGION WHILE THE
PARENT UPPER TROUGH REMAINS LODGED OVER THE GULF OF ALASKA. ON
THE HEELS OF THE EARLIER FRONTAL SYSTEM, ANOTHER SURFACE LOW IS
EXPECTED TO DEVELOP OFFSHORE AND DEEPEN AS IT MOVES GENERALLY
NORTHWESTWARD TOWARD THE OLYMPIC PENINSULA. AS THIS LOW
APPROACHES THE COAST ON SATURDAY, A STRONG SURFACE PRESSURE
GRADIENT WILL SET UP ACROSS THE REGION, ENCOURAGING GUSTY SOUTH
WINDS OF 35-40 MPH INLAND, AND 40-50 MPH ALONG THE COAST.
IN THE STRONGEST SCENARIO, ABOUT A 10% LIKELIHOOD, GUSTS OF
45-50 MPH INLAND AND 55-60 MPH ALONG THE COAST COULD YIELD MORE
WIDESPREAD WIND DAMAGE AND POWER OUTAGE IMPACTS; THIS FORECAST
REMAINS VERY SENSITIVE TO THE INTENSITY AND POSITION OF THE
COASTAL LOW, WITH ANY WEAKER OR DISPLACED LOW CENTER UNABLE TO
SUPPORT HIGHER-END WINDS.
PRECIPITATION CHANCES REMAIN ELEVATED THROUGH THE PERIOD, AS
ZONAL FLOW ORIENTED NEARLY PERPENDICULAR TO LOCAL TERRAIN WILL
CONTINUE SUNDAY BEHIND THE DEPARTING SHORTWAVE TROUGH. A
NOTABLE CHANGE IN THE MID-LEVELS WILL SEE 850 HPA TEMPERATURES
FALL FROM AROUND 5C TO -2C BEHIND THE BOUNDARY THROUGH SUNDAY
NIGHT, ALLOWING SNOW LEVELS TO FALL TO 3000-4000 FT OVER THE
CASCADES. PERSISTENT SHOWERY PRECIPITATION COMBINED WITH THIS
COLDER AIR MASS WILL SUPPORT SUSTAINED SNOW ACCUMULATIONS IN
HIGHER TERRAIN, ALTHOUGH SNOWFALL RATES ARE NOT EXPECTED TO
REACH FAR ABOVE 0.5" PER HOUR EVEN IN THE HIGH CASCADES. SNOW
WILL NONETHELESS ACCUMULATE AT PASS LEVEL AND TRAVELERS THROUGH
THE CASCADES SHOULD BE PREPARED FOR WINTER DRIVING CONDITIONS.
RECREATORS AT HIGHER ELEVATIONS SHOULD ALSO BE PREPARED FOR MORE
SIGNIFICANT ACCUMULATIONS AND RELATED IMPACTS. COOL AND SHOWERY
CONDITIONS WITH HIGH TEMPERATURES IN THE 40S TO MID 50S WILL
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK WHEN DRIER CONDITIONS
MAY FINALLY RETURN AS BRIEF RIDGING BUILDS OVERHEAD. -36
AVIATION
MAINLY VFR CONDITIONS ACROSS THE AREA AS A COLD FRONT
MOVES THROUGH THE AREA. SCATTERED LIGHT SHOWERS AND CLOUDS
BETWEEN 2-3 KFT HAVE DEVELOPED BUT NO SIGNIFICANT IMPACTS TO
ANY TERMINALS. GUIDANCE SUGGESTS A 70-90% CHANCE FOR MVFR ACROSS
THE COAST WITH A 20-40% CHANCE CONDITIONS ARE IFR THROUGH 6Z OR
SO. KAST DOES SHOW A DECENT (60-70) CHANCE FOR VFR CONDITIONS
TO DEVELOP LATE THIS EVENING AS LOW CLOUDS BECOME MORE SCATTERED
IN THE AREA. SOUTH WINDS 10-15 KT WITH GUSTS 20-25 KT EXPECTED.
INLAND CONDITIONS ARE EXPECTED TO BE MAINLY VFR THROUGH
SCATTERED MVFR CIGS ARE POSSIBLE WITH A 20-40% CHANCE AS THE
COLD FRONT PASSES THIS EVENING. PROBABILITIES INCREASE TO 40-60%
OVERNIGHT BEHIND THE FRONT. SOUTH TO SOUTHWEST WINDS 5-10 KT
WITH GUSTS TO 15 KT EXPECTED.
KPDX AND APPROACHES...PREDOMINATELY VFR CONDITIONS THROUGH THE
TAF PERIOD. 20-30% CHANCE OF BRIEF PERIODS OF MVFR CIGS THIS
AFTERNOON AND EVENING AS A COLD FRONT MOVES THROUGH THE AREA.
BETTER CHANCE FOR LOWERED CIGS LATE TONIGHT BEHIND THE FRONT
WITH A 40-70% CHANCE FOR MVFR CIGS FROM 10-18Z. WINDS SOUTH TO
SOUTHWEST 5-10 KT, POSSIBLE GUSTS TO 15 KT. /19
MARINE
AN ACTIVE WEATHER PATTERN CONTINUES THROUGH THE WEEKEND,
SUPPORTING PERIODS OF GUSTY WINDS AND STEEP SEAS. SEAS ARE
BRIEFLY EXPECTED TO FALL BELOW 10 FEET LATER THIS EVENING WITH
A PERIOD AROUND 12 SECONDS. A SMALL CRAFT ADVISORY IS IN EFFECT
FOR ALL MARINE ZONES THROUGH 5 PM THURSDAY TO ACCOUNT FOR STEEP
SEAS. CONDITIONS ON THE CALMER SIDE WILL BE SHORT LIVED AS A
DEEP LOW ACROSS THE GULF OF ALASKA WILL SEND A COLD FRONT
THROUGH THE WATERS. A WESTERLY SWELL 14-16 FEET AT 14-17 SECONDS
WILL ENTER THE WATERS LATE THURSDAY MORNING, PEAKING IN THE
AFTERNOON. WINDS WILL ALSO STRENGTHEN FROM THE SOUTH WITH
SUSTAINED WINDS 25-35 KT AND GUSTS 35-45 KT STARTING AROUND 5 PM
THURSDAY AND CONTINUING THROUGH AROUND 11 AM FRIDAY. THE GALE
WATCH HAS BEEN UPGRADED TO A GALE WARNING FOR THE 5 PM THURSDAY
TO 11 AM FRIDAY TIME FRAME, THROUGH THIS MAY NEED TO BE EXTENDED
DEPENDING ON TIMING OF THE SYSTEM.
CONDITIONS REMAIN ACTIVE OVERALL, THOUGH A BREAK IS EXPECTED FROM
GALE CONDITIONS FRIDAY AFTERNOON INTO FRIDAY NIGHT BEFORE THE NEXT
STRONG SYSTEM BRINGS ANOTHER ROUND OF GALES SATURDAY. THIS
WEEKEND SYSTEM HAS THE POTENTIAL TO BE STRONGER THEN THE
EARLIER SYSTEM WITH A 20-40% CHANCE OF STORM FORCE WIND GUSTS
ACROSS THE WATERS. THERE IS DECENT VARIABILITY IN THE MODELS AT
THIS POINT THOUGH AND WILL HEAVILY DEPEND ON WHERE THE SYSTEM
TRACKS. WAVE HEIGHTS MAY ALSO REACH 20-25 FEET WITH A 15-35%
CHANCE LATE SATURDAY INTO SUNDAY. /19
BEACH HAZARDS
A BEACH HAZARDS STATEMENT REMAINS IN EFFECT
ACROSS THE NORTHERN/CENTRAL OREGON COAST AND SOUTH WASHINGTON
COAST THROUGH FRIDAY MORNING AS A LONG PERIOD, WEST-NORTHWESTERLY
SWELL WILL BRING A HIGH THREAT FOR SNEAKER WAVES. RAZOR CLAM
DIGGERS AT THE COAST WILL NEED TO EXERCISE EXTREME CAUTION THIS
WEEK. SNEAKER WAVES CAN RUN UP SIGNIFICANTLY FARTHER ON A BEACH
THAN NORMAL, INCLUDING OVER ROCKS, LOGS, AND JETTIES. SNEAKER
WAVES CAN SUDDENLY KNOCK PEOPLE OFF OF THEIR FEET AND QUICKLY
PULL THEM INTO THE OCEAN WHICH MAY LEAD TO SERIOUS INJURY OR
DROWNING. CAUTION SHOULD BE USED WHEN IN OR NEAR THE WATER.
ALWAYS KEEP AN EYE ON THE WAVES, AND BE ESPECIALLY WATCHFUL OF
CHILDREN AND PETS. REMEMBER, NEVER TURN YOUR BACK ON THE OCEAN!
THE BEACH HAZARDS STATEMENT FOR THE SOUTH WASHINGTON COAST HAS
BEEN UPGRADED TO A HIGH SURF ADVISORY STARTING AT 5 PM THURSDAY
AND CONTINUING THROUGH 5 AM FRIDAY.
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...HIGH SURF ADVISORY FROM 5 PM THURSDAY TO 5 AM PDT FRIDAY FOR
WAZ201.
PZ...SMALL CRAFT ADVISORY UNTIL 5 PM PDT THURSDAY FOR PZZ210-251>253-
271>273.
GALE WARNING FROM 5 PM THURSDAY TO 11 AM PDT FRIDAY FOR PZZ210-
251>253-271>273.
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