873
FXUS66 KPQR 251201
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
401 AM PST WED FEB 25 2026
SYNOPSIS
CALMER CONDITIONS ARE EXPECTED THE NEXT SEVERAL DAYS
WITH LINGERING SHOWER CHANCES PRIMARILY PINNED ACROSS THE
COAST, COAST RANGE, AND THE TERRAIN OF SOUTHWEST WASHINGTON.
RAIN CHANCES THEN SHIFT TO CENTRAL OREGON SATURDAY INTO SUNDAY
AS A WEATHER SYSTEM MOVING INTO NORTHERN CALIFORNIA BRUSHES
THE REGION, BUT CONFIDENCE IS ONLY LOW TO MODERATE ON THE EXACT
NORTHERN EXTENT OF PRECIPITATIION. COMPLETELY DRY WEATHER THEN
RETURNS EARLY NEXT WEEK. CONDITIONS LIKELY REMAIN WITHIN TYPICAL
CLIMATOLOGICAL NORMALS THROUGH THE FORECAST PERIOD WITH NO
SIGNIFICANT WEATHER IMPACTS ON THE HORIZON.
DISCUSSION...NOW THROUGH TUESDAY
WE'VE TRANSITIONED TO A
POST-FRONTAL AIRMASS THIS MORNING AS THE ATMOSPHERIC RIVER
WHICH IMPACTED THE AREA HAS LONG DEPARTED THE REGION. PARTIAL
CLEARING FORM THE INLAND VALLEYS TO THE COAST IN ADDITION TO
LIGHT WINDS AND AMPLE SURFACE MOISTURE CONTINUES TO SUPPORT THE
DEVELOPMENT OF PATCHY FOG INTO THE SUNRISE HOURS TODAY, SOME OF
WHICH MAY BE LOCALLY DENSE (VISIBILITY <0.25 MILE). KEEP THIS
IN MIND WHEN YOU EMBARK ON YOUR MORNING COMMUTE. OTHERWISE,
CONDITIONS REMAIN MOSTLY DRY TODAY AS HIGH RESOLUTION GUIDANCE
KEEPS ANY LINGERING SHOWER ACTIVITY PINNED NEAR THE COAST OF
NORTHERN OREGON/WASHINGTON INTO THE TERRAIN FEATURES OF THE
COAST RANGE AND CASCADES. ALL IN ALL, MUCH CALMER AND QUIETER
WEATHER COMPARED TO THE PAST SEVERAL DAYS.
BOTH DETERMINISTIC AND ENSEMBLE GUIDANCE DEPICT THE FLOW ALOFT
BECOMING ZONAL THURSDAY INTO FRIDAY THROUGH THE WEEKEND. LOW
PRECIPITATION CHANCES CONTINUE ACROSS THE AREA THROUGH FRIDAY
MORNING, MAINLY LIMITED TO THE NORTH OREGON COAST AND COAST
RANGE NORTH OF LINCOLN CITY, FAR NORTHERN OREGON CASCADES, AND
SW WASHINGTON. LIMITED ACCUMULATION IS EXPECTED. COLDER AIR IS
EXPECTED TO BE FUNNELED INTO THE PACNW AS WELL. THIS COOLER
AIRMASS ALONG WITH ANOTHER ROUND OF CLEARING SKIES ACROSS THE
MAJORITY OF THE INTERIOR LOWLANDS LEADS TO COLDER OVERNIGHT
TEMPERATURES TONIGHT WITH A 60-90% CHANCE OF LOW TEMPERATURES
THURSDAY MORNING FALLING BELOW FREEZING IN THE CENTRAL/SOUTHERN
WILLAMETTE VALLEY AND COAST RANGE VALLEYS, AND A 40-60% CHANCE
FOR THE SW WASHINGTON LOWLANDS NORTH OF KALAMA (70-90% CHANCE TO
DROP BELOW FREEZING NEAR BATTLE GROUND/YACOLT). HOWEVER, IF
SKIES DON'T CLEAR AS EXPECTED, LOCATIONS WITH REMAINING CLOUD
COVER WILL NOT COOL QUITE AS MUCH AS IN THE FORECAST. IT'S WORTH
NOTING THERE IS A SLIGHT CHANCE FOR A RAIN/SNOW MIX SHOWER ABOVE
700-1500FT TONIGHT INTO THURSDAY MORNING AS WELL, BUT IMPACTS
APPEAR EXTREMELY LIMITED.
MOSTLY DRY CONDITIONS PERSIST FRIDAY THROUGH EARLY SATURDAY
WITH INLAND HIGH TEMPERATURES IN THE 50S AND MINIMUM
TEMPERATURES IN THE LOW TO MID 30S. UNCERTAINTY INCREASES IN THE
FORECAST SATURDAY AFTERNOON INTO LATE SUNDAY, PRIMARILY IN
REGARDS TO PRECIPITATION CHANCES/PLACEMENT. ENSEMBLE GUIDANCE IS
IN AGREEMENT THAT A CLOSED LOW, THE REMNANT OF THE LONGWAVE
TROUGH WHICH HELPED STEER THE ATMOSPHERIC RIVER OVERHEAD
PREVIOUS COUPLE OF DAYS, PROGRESSES WESTWARD INTO CALIFORNIA.
HOWEVER, UNCERTAINTY REMAINS IN HOW FAR NORTH ALONG THE
CALIFORNIA COAST THIS WILL OCCUR. A TRACK FURTHER NORTH WOULD
YIELD BETTER CHANCES FOR PRECIPITATION. LATEST FORECASTS
INDICATE PRECIPITATION CHANCES LIMITED TO ROUGHLY SOUTH OF
HIGHWAY 20 IN OREGON. ADDITIONALLY, PROBABILITIES FOR OVERNIGHT
TEMPERATURES FALLING BELOW FREEZING IN THE INTERIOR LOWLANDS
REMAIN LOW TO MODERATE, MAINLY AROUND 30-60%, DUE TO THE
UNCERTAINTY OF THIS CLOSED LOW AND MID TO HIGH CLOUD COVER BEING
EJECTED NORTHWARD. A BIT MORE OF A NORTHERLY TRACK THAN
EXPECTED WILL LIKELY KEEP LOW TEMPERATURES ABOVE FREEZING DUE TO
CLOUD COVER, BUT A MORE SOUTHERN TRACK COULD KEEP THE AREA FROM
BEING IMPACTED BY THICKER CLOUD COVER ASSOCIATED WITH THE
UPPER- LEVEL LOW AND ALLOW FOR THE JET STREAM TO DIP INTO OREGON
AND BRING COLDER TEMPERATURES. EITHER WAY, THE CLOSED LOW IS
EXPECTED TO MOVE EAST BY MONDAY AS A RIDGE OF HIGH PRESSURE
BUILDS OVERHEAD, LEADING TO INCREASING CONFIDENCE (80-90%) OF
DRY WEATHER MONDAY INTO TUESDAY. HOWEVER, THE PATTERN APPEARS
RATHER PROGRESSIVE (I.E. THE COMPLETELY DRY WEATHER WON'T LAST
FOREVER) WITH NEARLY 50-60% OF THE ENSEMBLE SPACE DEPICTING A
SHORTWAVE TROUGH AND FRONTAL BOUNDARY INTRODUCING BETTER CHANCES
FOR PRECIPITATION AROUND WEDNESDAY NEXT WEEK. -99/03
AVIATION
SURFACE OBSERVATIONS CONTINUE TO SHOW WIDE MIX OF
VFR TO IFR AND LIFR CIGS/VIS ACROSS THE REGION APPROACHING
SUNRISE THIS MORNING THANKS IN-PART TO CLEARING AND LIGHT WINDS
FACILITATING FOG AND LOW STRATUS FORMATION WHICH IS IMPACTING
SEVERAL TERMINALS. EXPECT FLUCTUATIONS TO CONTINUE THROUGH THE
MORNING AS FOG/LOW STRATUS STARTS TO LIFT WHILE "SLOSHING"
AROUND THE INLAND VALLEYS. OVERALL, HIGH RESOLUTION GUIDANCE
POINTS TO A TREND BACK TO MVFR BY 18-20Z FOLLOWED BY THE RETURN
OF VFR CONDITIONS THIS AFTERNOON AND EVENING - LOW TO MODERATE
CONFIDENCE REGARDING THE EXACT TIMING OF THIS TRANSITION. HEADED
INTO THURSDAY MORNING, PATCHY FOG WILL AGAIN BE POSSIBLE BUT
CONFIDENCE IN PLACEMENT AND TIMING IS TO LOW TO ADD IT AS A
PREVAILING CONDITIONS AT THIS TIME. WINDS STAY FAIRLY LIGHT,
GENERALLY LESS THAN 5-10 KNOTS TODAY AND TONIGHT.
KPDX AND APPROACHES...LOW STRATUS AND FOG IS DEVELOPING WITHIN
THE IMMEDIATE VICINITY OF THE TERMINAL THIS MORNING WITH THE
BEST CHANCE (40-50%) FOR A PERIOD OF IFR/LIFR CONDITIONS DUE TO
LOW CIGS/VIS BETWEEN 13-16Z, AFTER WHICH POINT WE SHOULD
QUICKLY TREND BACK TO MVFR THEN VFR. IT SHOULD BE NOTED FORECAST
CONFIDENCE THROUGH 16-18Z THIS MORNING IS RATHER LOW GIVEN THE
PATCHY/SLOSHY NATURE OF THE FOG SHOWN ON SATELLITE OBSERVATIONS
- LARGE HOURLY FLUCTUATIONS ARE POSSIBLE. -99
MARINE
WITH OUR PREVIOUS WEATHER DISTURBANCE NOW WELL OFF TO
THE EAST BOTH SEAS AND WINDS HAVE CALMED WITH BOUY OBSERVATIONS
EARLY THIS MORNING SHOWING SEAS AROUND 5 TO 7 FT AT 9 SECONDS
ACCOMPANIED BY WIND GUSTS UNDER 15-20 KNOTS. HEADED THROUGH
THURSDAY AND THURSDAY NIGHT, CONFIDENCE IS HIGH SEAS REMAIN BELOW
8 FT WITH WIND GUSTS HOLDING BETWEEN 10-20 KNOTS (HIGHEST OVER THE
OUTER WATERS NORTH OF CAPE FALCON). LOCAL GUIDANCE SHOWS A MIXED
BAG OF SWELLS WITH A PRIMARY NORTHWESTERLY SWELL AND A SOUTHERLY
FRESH SWELL THAT THEN TRANSITIONS INTO A TRUE SECONDARY SWELL.
WHILE A COMPLICATED SWELL ORGANIZATION, WE'LL SEE WIDESPREAD SEAS
RISE TO ~10 FT ON FRIDAY INTO SATURDAY. THE SEA STATE DIMINISHES
AGAIN BACK INTO THE 5-7FT RANGE BY EARLY NEXT WEEK. -99/27
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
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