153
FXUS66 KPQR 191801 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1100 AM PDT SUN OCT 19 2025
...UPDATED AVIATION DISCUSSION AND WATCHES/WARNINGS/ADVISORIES
SECTION...
SYNOPSIS
A FRONT WILL PUSH EASTWARD TOWARDS THE CASCADES THIS
MORNING, BRINGING A TRANSITION FROM THE STEADY STRATIFORM RAIN THAT
WAS OBSERVED SATURDAY NIGHT TO POST-FRONTAL SHOWERS AND
THUNDERSTORMS. STRONGER SHOWERS OR STORMS WILL HAVE THE POTENTIAL TO
PRODUCE GUSTY OUTFLOW WINDS UP TO 45 MPH THIS MORNING AND AFTERNOON
DRY AND CALM WEATHER RETURNS SUNDAY NIGHT AND CONTINUES THROUGH
TUESDAY NIGHT AS HIGH PRESSURE RETURNS. THEN, A SERIES OF WEATHER
SYSTEMS FROM LATE WEDNESDAY ONWARD WILL BRING SEVERAL ROUNDS OF
WIDESPREAD RAIN TO THE AREA, LIKELY HEAVIEST ON FRIDAY. BREEZY SOUTH
WIND APPEAR LIKELY LATE THURSDAY INTO FRIDAY AND AGAIN FRIDAY NIGHT
INTO SATURDAY, HOWEVER PROBABILITIES FOR IMPACTFUL WIND GUSTS OF
45-55 MPH OR STRONGER HAVE DECREASED A BIT, ESPECIALLY FOR INLAND
AREAS.
SHORT TERM...NOW THROUGH TUESDAY NIGHT
RADAR AND SURFACE WEATHER
OBSERVATIONS FROM 3 AM SUNDAY SHOWED A BAND OF MODERATE TO LOCALLY
HEAVY STRATIFORM RAIN EXTENDING ALONG AND AHEAD OF A
SOUTHWEST-NORTHEAST ORIENTED FRONTAL BOUNDARY IN THE WILLAMETTE
VALLEY AND SOUTH WA CASCADES. ALTHOUGH PERSISTENT STRATIFORM RAIN
WILL CONTINUE CLEARING THE AREA FROM WEST TO EAST TOWARDS SUNRISE,
POST-FRONTAL SHOWERS AND THUNDERSTORMS WILL QUICKLY MOVE IN AND
CONTINUE SUNDAY MORNING THROUGH EARLY TO MID SUNDAY EVENING.
THUNDERSTORM PROBABILITIES PEAK BETWEEN 15-25% SUNDAY AFTERNOON,
HIGHEST OVER SOUTHWEST WA AND THE PORTLAND/VANCOUVER METRO. NOTE
STRONGER SHOWERS AND THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE
GUSTY OUTFLOW WINDS UP TO 45 MPH, BRIEF HEAVY RAIN, AND POTENTIALLY A
FUNNEL CLOUD OR LANDSPOUT GIVEN THE FAVORABLE VERTICAL WIND PROFILE
IN PLACE TODAY. THIS COULD RESULT IN HIGHLY LOCALIZED WIND DAMAGE.
SHOWERS DIMINISH SUNDAY NIGHT INTO MONDAY AS HIGH PRESSURE RETURNS TO
THE AREA. THIS WILL BRING DRY WEATHER, SEASONABLE TEMPERATURES AND
RELATIVELY LIGHT WINDS MONDAY AND TUESDAY. OFFSHORE FLOW BEGINS TO
INCREASE A BIT TUESDAY NIGHT, BRINGING BREEZIER EAST WINDS TO THE
CASCADES, WESTERN COLUMBIA RIVER GORGE AND TROUTDALE AREA. TUESDAY IS
SHAPING UP TO BE THE WARMEST DAY OF THE WEEK WITH HIGH TEMPERATURES
MAINLY IN THE MID TO UPPER 60S ACROSS THE LOWLANDS. -23
LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
THE WEATHER PATTERN
STILL LOOKS ACTIVE FOR THE LONG TERM FORECAST AS A SERIES OF WEATHER
SYSTEMS BRINGS WIDESPREAD RAIN AND BREEZY WINDS TO THE AREA. MODELS
ARE IN FAIRLY GOOD AGREEMENT ON WEDNESDAY, SUGGESTING A WEAKER
FRONTAL SYSTEM WILL PUSH INLAND LATE IN THE DAY AND BRING LIGHT RAIN
INTO THE AREA. THEN, A POTENTIALLY STRONGER SYSTEM ARRIVES THURSDAY
NIGHT INTO FRIDAY AS A MODERATE ATMOSPHERIC RIVER PUSHES INLAND. THIS
SYSTEM WILL BRING HEAVIER RAIN FROM THE COAST TO THE CASCADES; NBM
PROBABILITIES FOR 1" OF RAIN OR MORE RANGE BETWEEN 50-85%, HIGHEST
OVER THE MOUNTAINS AND ALONG THE COAST. PROBABILITIES FOR 2" OF RAIN
OR MORE DROP TO 5-15%, EXCEPT 40-60% FOR THE COAST AND WESTERN SLOPES
OF THE COAST RANGE AND CASCADES. GIVEN THE RELATIVELY LOW RIVER
LEVELS LEADING INTO THIS EVENT, RIVER FLOODING IS NOT EXPECTED.
DEPENDING ON FRONTAL FORCING AND HOURLY RAIN RATES, CANNOT COMPLETELY
RULE OUT MINOR URBAN FLOODING AND SMALL STREAM FLOODING.
BREEZY SOUTH WINDS WILL ACCOMPANY THIS SYSTEM AS WELL, HOWEVER THE
PROBABILITY FOR IMPACTFUL WIND GUSTS OVER 45 MPH HAS FALLEN TO 1-10%,
EXCEPT 30-50% AT THE COAST WHERE STRONGER GUSTS ARE LIKELY. WIND
CONCERNS INCREASE SATURDAY INTO SATURDAY NIGHT AS A CLOSED SURFACE
LOW OVER THE NORTHEAST PACIFIC MOVES TOWARDS THE COAST BEHIND THE
ATMOSPHERIC RIVER. THAT SAID, UNCERTAINTY REMAINS HIGH AS MODELS AND
THEIR ENSEMBLES CONTINUE TO SHOW A LARGE DEGREE OF MODEL SPREAD IN
REGARDS TO THE STRENGTH AND TRACK OF THIS LOW. CHANCES HAVE
DECREASED SLIGHTLY FOR WIND GUSTS OVER 45 MPH WITH THIS SYSTEM, DOWN
TO 10-20% FOR INLAND AREAS AND 30-40% FOR THE COAST AND COASTAL
MOUNTAINS. CHANCES FOR WIND GUSTS OVER 55 MPH HAVE DECREASED TO 1-5%
INLAND AND 15-25% AT THE COAST. WHILE WIND GUSTS OF THIS MAGNITUDE
ARE UNLIKELY TO OCCUR, THE POTENTIAL IS WORTH MENTIONING AS THESE
WINDS WOULD BE STRONG ENOUGH TO RESULT IN WIDESPREAD DOWNED TREES
AND POWER OUTAGES.
ALSO WORTH MENTIONING IS LOWERING SNOW LEVELS SATURDAY NIGHT AS
COLDER AIR ALOFT SETTLES OVER THE AREA. THE DETERMINISTIC NBM
SUGGESTS SNOW LEVELS WILL FALL TO 4000-4500 FT, WHILE THE 10TH
PERCENTILE SUGGESTS SNOW LEVELS DOWN TO 3000-3500 FT (10% CHANCE OF
OCCURRING). IN BOTH CASES, ACCUMULATING SNOW WOULD OCCUR AT PASS
LEVEL, RESULTING IN SOME TRAVEL IMPACTS. -23
AVIATION
RADAR IMAGERY AND TERMINAL OBSERVATIONS AS OF LATE
SUNDAY MORNING DEPICTS POST-FRONTAL SHOWER ACTIVITY ACROSS NORTHWEST
OREGON WITH A MIX OF MVFR AND VFR CIGS. EXPECT THIS TREND TO
CONTINUE THROUGH 00Z MON WITH A 15-25% CHANCE FOR THUNDERSTORMS. ANY
PASSING THUNDERSTORMS MAY BRING LIGHTNING, BRIEF HEAVY RAIN, GUSTY
OUTFLOW WINDS, SMALL HAIL, AND/OR FUNNEL CLOUDS. VISIBILITY MAY
BRIEFLY FALL TO IFR/MVFR THRESHOLDS DURING PERIODS OF HEAVY RAIN.
AFTER 00Z MON, SHOWER ACTIVITY DECREASES AND CONDITIONS BEGIN TO
GRADUALLY DRY UP. TONIGHT INTO MONDAY, HIGH PRESSURE RE-BUILDS,
RETURNING DRY WEATHER AND PREDOMINATELY VFR CONDITIONS. BREEZY
SOUTHWESTERLY WINDS WITH GUSTS OF 20-25 KT CONTINUE THROUGH THIS
AFTERNOON, GRADUALLY WEAKENING THIS EVENING. VARIABLE WINDS AROUND 5
KT OR LESS RETURN TONIGHT ACROSS THE AREA. THESE LIGHT WINDS
COMBINED WITH A MOIST SURFACE AND INCREASED CLEARING WILL RESULT IN
POTENTIAL FOG DEVELOPMENT OVERNIGHT. GUIDANCE SUGGESTS A 30-50%
CHANCE FOR LIFR/IFR CIGS/VIS FROM FOG ACROSS THE CENTRAL AND
SOUTHERN WILLAMETTE VALLEY BETWEEN 12-17Z MON, AND A 20-40% CHANCE
IN THE FAR WESTERN PORTLAND METRO (KHIO).
KPDX AND APPROACHES...PREDOMINATELY VFR THROUGH 00Z MON WITH
OCCASIONAL MVFR CIGS POSSIBLE DURING PERIODS OF HEAVY SHOWERS OR
THUNDERSTORMS. 15-25% CHANCE FOR THUNDERSTORMS THROUGH 00Z MON.
SOUTHWESTERLY WIND GUSTS OF 20-25 KT THROUGH THIS AFTERNOON,
WEAKENING THIS EVENING. -10
MARINE
WINDS HAVE VEERED TO THE WEST BEHIND A FRONTAL PASSAGE
EARLIER THIS MORNING. STEEP AND HAZARDOUS SEAS UP TO 20 FT ARE STILL
ON TRACK TO DEVELOP BY SUNDAY AFTERNOON. THEREFORE, A HAZARDOUS SEAS
WARNING REMAINS IN EFFECT FOR ALL WATERS INCLUDING THE COLUMBIA
RIVER BAR FROM 0800 SUNDAY TO 0500 MONDAY.
SEAS WILL DECREASE SUBSTANTIALLY SUNDAY NIGHT INTO MONDAY TO AROUND
10 FT AS HIGH PRESSURE RETURNS AND WINDS BECOME LIGHT AND VARIABLE.
THEN, ANOTHER POTENT NORTHWESTERLY SWELL ARRIVES TUESDAY AFTERNOON
AND EVENING PUSHING SEAS UP TO AROUND 15-17 FT RANGE AGAIN. AN
ACTIVE WEATHER PATTERN IS THEN EXPECTED TO CONTINUE LATE WEDNESDAY
THROUGH FRIDAY NIGHT WITH A PERIOD OF STORM FORCE SOUTHERLY WIND
GUSTS OF 48 KT OR STRONGER POSSIBLE (20-30% CHANCE OVER THE OUTER
WATERS AND A 30-50% CHANCE OVER THE INNER WATERS).
NOTE PROBABILITIES ARE HIGHER OVER THE INNER WATERS DUE TO THE
POTENTIAL DEVELOPMENT OF A COASTAL JET DURING THAT TIME. THIS SYSTEM
ALSO HAS THE POTENTIAL TO PUSH SEAS UP 15 TO 20 FT AGAIN (NEAR 100%
CHANCE FOR SEAS OVER 15 FT AND A 10% CHANCE FOR SEAS OVER 20 FT). -23
BEACH HAZARDS
A NORTHWESTERLY SWELL OF 15-18 FT AT 15-16
SECONDS IS FORECAST TO ENTER THE WATERS SUNDAY AFTERNOON. THIS
INCREASE IN WAVE ENERGY WILL SUPPORT A HIGH THREAT FOR SNEAKER WAVES
THROUGH SUNDAY EVENING. A BEACH HAZARDS STATEMENT REMAINS IN EFFECT
ACROSS THE CENTRAL AND NORTHERN OREGON COAST AND THE SOUTH
WASHINGTON COAST THROUGH SUNDAY EVENING TO HELP MESSAGE THIS THREAT.
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! -10/23
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ210.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT MONDAY 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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