179
FXUS66 KPQR 112230
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
230 PM PST SUN JAN 11 2026
SYNOPSIS
A SLOW-MOVING FRONTAL BOUNDARY WILL BRING PERIODS
OF LIGHT RAIN TO SOUTHWEST WASHINGTON AND ALONG THE FAR NORTH
OREGON COAST NOW THROUGH MONDAY MORNING, WHILE THE REST OF
WESTERN OREGON STAYS DRY WITH LIGHT WINDS AND HIGH CLOUDS. A
VERY STRONG HIGH PRESSURE SYSTEM WILL STRENGTHEN AND REMAIN
ANCHORED OVER THE PACIFIC NORTHWEST TUESDAY THROUGH NEXT
WEEKEND. THIS WILL RESULT IN A PROLONGED STRETCH OF DRY WEATHER
WITH ABNORMALLY MILD TEMPERATURES AND LIGHT WINDS. EXPECT AT
LEAST 6 TO 8 CONSECUTIVE DRY DAYS IN A ROW.
DISCUSSION...NOW THROUGH SATURDAY NIGHT
ASIDE FROM PERIODS OF
LIGHT RAIN OVER PORTIONS OF SOUTHWEST WASHINGTON AND THE FAR NORTH
OREGON COAST THROUGH SUNDAY NIGHT/MONDAY MORNING, THE WEATHER
FORECAST OVER THE NEXT 6 TO 8 DAYS IS DOMINATED BY A PROLONGED
STRETCH OF DRY AND CALM CONDITIONS WITH ABOVE NORMAL TEMPERATURES
FOR THIS TIME OF YEAR. THE PRIMARY CAUSE OF THESE CONDITIONS IS
AN ANOMALOUSLY STRONG HIGH PRESSURE SYSTEM THAT MODELS AND
THEIR ENSEMBLES CONTINUE TO SHOW A BROAD AREA OF HIGH PRESSURE
ANCHORED OVER THE PAC NW/ NE PACIFIC THROUGH THIS WEEK AND INTO
NEXT WEEKEND. MODELS ALSO SHOW THAT THE RIDGE WILL AMPLIFY OVER
WESTERN OR AND WA MONDAY THROUGH WEDNESDAY. THE OVERALL SYNOPTIC
PATTERS HAS A WELL ESTABLISHED, UPPER LEVEL RIDGE THAT
TRANSITIONS INTO A REX BLOCKING PATTERN TOWARDS THE LATTER PART
OF THIS WEEK. IT SHOULD BE NOTED THAT MODELS ARE SHOWING THE
RIDGE FLATTENING AS ALASKAN LOWS RIDE THE CREST OF THE RIDGE,
BUT THESE SYSTEMS ARE NOT EXPECTED TO BREAK THE OVERALL BLOCKING
PATTERN. 500 MB HEIGHTS LOOK TO PEAK NEAR 590 DM OVER NORTHERN
CALIFORNIA AND SOUTHERN OREGON, AND NEAR 585 DM OVER NORTHERN
OREGON. NOTE THESE VALUES ARE AROUND THE 95TH-99TH PERCENTILE
COMPARED TO CLIMATOLOGY, WHICH MEANS HIGH PRESSURE OF THIS
MAGNITUDE IS QUITE RARE THIS TIME OF YEAR, ESPECIALLY GIVEN THE
EXTENDED DURATION.
AT THIS TIME, IT IS NOT CLEAR EXACTLY WHEN THE RIDGE/BLOCKING
PATTERN WILL BREAK DOWN AND PRECIPITATION WILL RETURN, HOWEVER
SOME MODEL GUIDANCE IS SUGGESTING THAT A PATTERN CHANGE COULD
OCCUR AROUND JAN. 21-23 WITH PRECIPITATION COMING BACK INTO THE
CONVERSATION. STILL, CONFIDENCE ON THIS OCCURRING IS VERY LOW
GIVEN THAT WE ARE LOOKING AT MODEL SOLUTIONS AROUND 10 DAYS IN
THE FUTURE. ALSO, BLOCKING PATTERNS (VIA FORECASTER PATTERN
RECOGNITION) WILL TYPICALLY LAST 7-8 DAYS OR 10-11 DAYS. UNTIL
THEN, EXPECT MORE OF THE SAME EACH DAY WITH VARYING DEGREES OF
CLOUD COVER, LIGHT WINDS, AND MILD TEMPERATURES WITH AFTERNOON
HIGHS RUNNING ANYWHERE FROM 5-15 DEGREES ABOVE NORMAL FOR THIS
TIME OF YEAR AS DAYTIME HIGHS ARE EXPECTED TO BE GENERALLY IN
THE 50S TO 60S. THE NBM SUGGESTS HIGHS WILL RANGE IN THE LOW TO
UPPER 50S LOWLANDS, MID 50S TO MID 60S IN THE CASCADE FOOTHILLS
AND LOW TO UPPER 50S ALONG THE COAST. CURRENTLY, THE WARMEST
DAYS IN THE FORECAST ARE THURSDAY AND FRIDAY.
THE COOLEST DAYTIME TEMPERATURES WILL OCCUR IN PORTIONS OF THE
CENTRAL AND SOUTHERN WILLAMETTE VALLEY WHERE CHANCES FOR FOG AND
LOW CLOUDS EACH NIGHT/MORNING MAY LIMIT DAYTIME HEATING AND
KEEP HIGHS CLOSER TO 50 DEGREES. THE REASON THE OREGON CASCADE
FOOTHILLS WILL LIKELY BE WARMEST IS DUE TO A COMBINATION OF MORE
HOURS OF SUNSHINE AND THE FACT THAT THESE ELEVATIONS ARE HIGH
ENOUGH TO POKE ABOVE A STRONG LOW-LEVEL TEMPERATURE INVERSION
THAT WILL REMAIN IN PLACE THROUGH THE WEEK, THUS TAPPING INTO
RELATIVELY WARMER AIR ALOFT. LOCATIONS SUCH AS OAKRIDGE WILL
FEEL MORE SPRING LIKE RATHER THAN TYPICAL MID JANUARY DAYTIME
HIGHS.
IT SHOULD BE NOTED THAT A HIGH PRESSURE ALOFT WILL RESULT IN A
RATHER STABLE ATMOSPHERE IE...MINIMAL AIR MIXING AND MOVEMENT.
THIS WILL LEAD TO THE POTENTIAL FOR DEGRADED AIR QUALITY AS THIS
PATTERN IS EXPECTED TO PERSIST. SO, PROLONGED MULTI-DAY STRETCH
OF VERY LOW VERTICAL MIXING HEIGHTS, WHICH HELPS TRAP AIR
POLLUTANTS NEAR THE SURFACE, WILL BRING ABOUT STAGNANT AIR.
AS A RESULT OF THESE CONDITIONS, WE HAVE ISSUED A AIR
STAGNATION ADVISORY FOR THE MAJORITY OF THE WILLAMETTE VALLEY
AND IT COULD EXPAND AS THE WEEK PROGRESSES. STATE AIR QUALITY
AGENCIES HIGHLY RECOMMEND THAT NO OUTDOOR BURNING OCCUR AND THAT
RESIDENTIAL WOOD BURNING DEVICES BE LIMITED AS MUCH AS
POSSIBLE. ACCORDING TO STATE AIR QUALITY AGENCIES, PROLONGED
PERIODS OF STAGNANT AIR CAN HOLD POLLUTANTS CLOSE TO THE GROUND
WHERE PEOPLE LIVE AND BREATHE. CHECK WITH YOUR LOCAL BURN AGENCY
FOR ANY CURRENT RESTRICTIONS IN YOUR AREA.
ALSO, PEOPLE WITH RESPIRATORY ILLNESS SHOULD FOLLOW THEIR
PHYSICIAN'S ADVICE FOR DEALING WITH HIGH LEVELS OF AIR POLLUTION
DURING PERIODS OF STAGNANT AIR, ESPECIALLY IF AN AIR QUALITY
ALERT IS IN EFFECT FOR YOUR AREA. TO SEE IF AN AIR QUALITY ALERT
IS IN EFFECT FOR YOUR AREA, GO TO WWW.WEATHER.GOV/PQR AND LEFT-
CLICK YOUR LOCATION ON THE HOMEPAGE MAP DISPLAY. ALTERNATIVELY,
YOU COULD ALSO TYPE YOUR LOCATION INTO THE SEARCH BAR FOUND ON
THE TOP-LEFT HAND SIDE OF THE HOMEPAGE. FROM THERE, YOU WILL SEE
AN AIR QUALITY ALERT LISTED AT THE TOP IF ONE IS IN EFFECT FOR
YOUR LOCATION; YOU CAN CLICK THE ALERT TO READ MORE DETAILS IF
APPLICABLE. YOU CAN ALSO FIND THE CURRENT AIR QUALITY INDEX
(AQI) FOR YOUR LOCATION AT WWW.AIRNOW.GOV. /42-23
AVIATION
THIS AFTERNOON VFR CONDITIONS CURRENTLY PREVAIL ACROSS
THE REGION OUTSIDE OF KAST WHERE THE SOUTHERN EDGE OF A FRONTAL
BOUNDARY HAS KEPT OCCASIONAL LIGHT RAIN AND MVFR CIGS IN PLACE.
HEADED THROUGH TONIGHT THE PRIMARY FLIGHT IMPACTS WILL BE
ASSOCIATED WITH THE POTENTIAL FOR PATCHY FOG WITHIN PORTIONS OF
THE WILLAMETTE VALLEY AND TUALATIN VALLEY. CONFIDENCE IS STILL
RATHER LOW REGARDING EXACTLY WHERE AND WHEN FOG WILL DEVELOP - IF
IT EVEN DEVELOPS AT ALL. SIMILAR TO THE PAST COUPLE OF NIGHTS,
BROKEN HIGH CLOUDS WILL LARGELY WORK AGAINST WIDESPREAD FOG
FORMATION, BUT THIS SETUP HAS GENERALLY RESULTED IN PATCHY FOG AND
FLUCTUATING VISIBILITIES AT KHIO, KSLE, AND KUAO. KHIO HAS THE
HIGHEST CHANGE FOR FOG OF ANY TAF SITE, WITH PROBABILITIES
REACHING 30-50% FOR SURFACE VISIBILITIES BELOW 1 SM BETWEEN 09-18Z
MONDAY. PROBABILITIES FOR FOG RANGE BETWEEN 15-30% AT KUAO, KSLE
AND KEUG. WE'LL ALSO HAVE TO WATCH A PUSH OF LOW CLOUDS FROM THE
WEST AT KONP WHICH WOULD DEGRADE FLIGHT CONDITIONS AFTER 10-14Z
MONDAY. OTHERWISE, VFR CONDITIONS ARE FAVORED TO PERSIST AT KPDX
AND KTTD. IT'S WORTH NOTING JUST OUTSIDE OF THE TAF PERIOD (MONDAY
NIGHT INTO TUESDAY MORNING) PROBABILITIES FOR FOG AND LIFR/IFR
CONDITIONS ACROSS THE INLAND VALLEYS INCREASE SIGNIFICANTLY.
KPDX AND APPROACHES...EXPECT VFR FLIGHT CONDITIONS TO PREVAIL
THROUGH THE TAF PERIOD AS HIGH CLOUDS STREAM OVERHEAD. LIGHT
ESE WINDS CONTINUE AS WELL HELPING TO PREVENT ANY FOG FORMATION
LOCALLY. -99
.MARINE..A LONG PERIOD SOUTHWESTERLY SWELL HAS BEGUN TO ARRIVE
THIS AFTERNOON LIKELY PUSHING SEAS UP INTO THE 14 TO 17 FT RANGE
FOR THE OVERNIGHT HOURS AND MUCH OF MONDAY, PRIMARILY NORTH OF
CAPE FOULWEATHER. HOWEVER, SEAS WILL MOST LIKELY BE HIGHEST OVER
THE NORTHERN WATERS TO THE NORTH OF CAPE FALCON WHERE SOUTHERLY
WINDS WILL BE STRONGEST, GUSTING AS HIGH AS 28-35 KT. NOTE GALE
FORCE WIND GUSTS OF 34-35 KT ARE EXPECTED TO BE ISOLATED AND
INFREQUENT TONIGHT, BUT STILL SOMETHING TO KEEP IN MIND BEFORE
WINDS SLOWLY DECREASE ON MONDAY.
GIVEN THE EXPECTED SEA STATE, A HAZARDOUS SEAS WARNING REMAINS IN
EFFECT FOR ALL MARINE ZONES THROUGH MONDAY AFTERNOON NORTH OF
CAPE FOULWEATHER IN ADDITIONAL TO PZZ273 THROUGH THIS EVENING.
SEAS ARE EXPECTED TO PEAK NEAR 15-16 FT OVER THE MAIN CHANNEL OF
THE COLUMBIA RIVER BAR AS WELL. ONCE WE GET INTO MONDAY NIGHT SEAS
GRADUALLY DECREASE AS WE TRANSITION TO A BRIEF PERIOD SMALL CRAFT
ADVISORY CONDITIONS. BY TUESDAY AFTERNOON CONFIDENCE IS MODERATE
TO HIGH SEAS FALL BACK INTO THE 8-9 FT RANGE ACROSS THE INNER AND
OUTER WATERS. HEADED THROUGH THE REST OF THE WEEK, A RIDGE OF HIGH
PRESSURE AMPLIFIES OVERHEAD RESULTING IN RATHER CALM CONDITIONS
BY WINTER-TIME STANDARDS. COME FRIDAY, SEAS LIKELY BOTTOM OUT
AROUND 4-6FT AT 11-12 SECONDS. -99
BEACH HAZARDS
THERE IS A HIGH THREAT OF SNEAKER WAVES AT
THE COAST THROUGH MONDAY AFTERNOON DUE TO A CONTINUED LONG-
PERIOD SOUTHWESTERLY TO WESTERLY SWELL. SNEAKER WAVES CAN
CREATE POTENTIALLY LIFE-THREATENING CONDITIONS AS WAVES MAY RUN
FARTHER UP THE BEACH THAN EXPECTED. THESE WAVES CAN EASILY CATCH
PEOPLE OFF GUARD AND CAUSE BEACHGOERS TO BE KNOCKED OFF THEIR
FEET AND PULLED OUT INTO COLD OCEAN WATERS. NEVER TURN YOUR BACK
TO THE OCEAN. CAUTION SHOULD BE USED WHEN IN OR NEAR THE WATER,
AND THOSE WITH CHILDREN SHOULD BE ESPECIALLY WATCHFUL. SNEAKER
WAVES CAN LIFT OR ROLL LARGE, HEAVY LOGS OR ROCKS WHICH CAN LEAD
TO SERIOUS DEATH OR INJURY. KEEP OFF ROCKS, LOGS, AND JETTIES
NEAR THE WATERLINE ON BEACHES. /42
PQR WATCHES/WARNINGS/ADVISORIES
OR...AIR STAGNATION ADVISORY UNTIL 4 AM PST FRIDAY FOR ORZ109>111-
114>118.
WA...AIR STAGNATION ADVISORY UNTIL 4 AM PST FRIDAY FOR WAZ205-206.
PZ...SMALL CRAFT ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR PZZ210.
HAZARDOUS SEAS WARNING UNTIL 4 PM PST MONDAY FOR PZZ210.
HAZARDOUS SEAS WARNING UNTIL 4 PM PST MONDAY FOR PZZ251-252-271-
272.
SMALL CRAFT ADVISORY FROM 4 PM MONDAY TO 10 AM PST TUESDAY FOR
PZZ251-252-271-272.
SMALL CRAFT ADVISORY UNTIL 4 AM PST TUESDAY FOR PZZ253.
HAZARDOUS SEAS WARNING UNTIL 10 PM PST THIS EVENING FOR PZZ273.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 4 AM PST TUESDAY
FOR PZZ273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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