161
FXUS66 KPQR 242229
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
229 PM PST TUE FEB 24 2026
SYNOPSIS
SCATTERED SHOWERS CONTINUE ACROSS THE REGION TODAY,
BECOMING ISOLATED AND LIMITED MAINLY TO FAR NORTHERN OREGON AND
SW WASHINGTON WEDNESDAY THROUGH FRIDAY. RAIN CHANCES THEN SHIFT
TO CENTRAL OREGON SATURDAY INTO SUNDAY AS A WEATHER SYSTEM
MOVING INTO NORTHERN CALIFORNIA BRUSHES CENTRAL OREGON, BUT
CONFIDENCE IS LOW IN DETAILS. 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...TUESDAY AFTERNOON THROUGH MONDAY
THE
ATMOSPHERIC RIVER THAT IMPACTED NW OREGON AND SW WASHINGTON
THROUGH LAST NIGHT SHIFTED INTO S OREGON AND N CALIFORNIA THIS
MORNING AS THE SURFACE FRONT SHIFTED JUST SOUTH OF LANE COUNTY,
LEAVING SCATTERED SHOWERS ACROSS THE AREA IN THE WAKE OF THE
FRONT. SATELLITE IMAGERY TUESDAY AFTERNOON SHOWS THE UPPER
TROUGH THAT FUNNELED THE ATMOSPHERIC RIVER INTO THE PACNW HAS
PINCHED OFF INTO A CUT OFF LOW IN THE EASTERN PACIFIC WEST OF
CALIFORNIA, AND ENSEMBLE GUIDANCE INDICATES THIS LOW WILL
RETROGRADE WEST BEFORE PUSHING BACK EAST TOWARDS THE WEST COAST
LATER THIS WEEK. IN THE MEANTIME, SCATTERED SHOWERS CONTINUE
ACROSS THE REGION THROUGH WEDNESDAY AS A WEAK SHORTWAVE MOVES
FROM THE NORTH THROUGH WASHINGTON AND OREGON. SNOW LEVELS WILL
LOWER TONIGHT WITH THE INCOMING SHORTWAVE, FALLING TO 2500-3500
FT NORTH OF LANE COUNTY AND 3500-4500 FT IN LANE COUNTY BY EARLY
WEDNESDAY MORNING. HOWEVER, WITH SHOWERS BEING SCATTERED AND
LIMITED IN PRECIPITATION, NOT MUCH SNOW IS EXPECTED OVER THE
CASCADES, MAYBE UP TO 2 INCHES IN THE EARLY MORNING HOURS
WEDNESDAY AT WILLAMETTE PASS.
ENSEMBLE GUIDANCE INDICATES FLOW BECOMES 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 BEHIND WEDNESDAY'S SHORTWAVE. THIS ALONG WITH
CLEARING SKIES ACROSS THE MAJORITY OF THE INTERIOR LOWLANDS WILL
LEAD TO COLDER OVERNIGHT TEMPERATURES WEDNESDAY NIGHT WITH A
60-90% CHANCE OF LOW TEMPERATURES THURSDAY MORNING FALLING BELOW
FREEZING IN THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY AND A
40-60% CHANCE FOR THE SW WASHINGTON LOWLANDS. HOWEVER, IF SKIES
DON'T CLEAR AS EXPECTED, LOCATIONS WITH REMAINING CLOUD COVER
WILL NOT COOL QUITE AS MUCH. THERE'S AN OFF CHANCE (~5-10%) AN
ISOLATED SHOWER WANDERS OFF THE COAST RANGE OR WILLAPA HILLS
INTO THE SOUTHWEST WASHINGTON LOWLANDS DURING THIS PERIOD, WHICH
WOULD HAVE THE POTENTIAL TO BE A RAIN/SNOW MIX IF TEMPERATURES
DO LOWER NEAR OR BELOW FREEZING. HOWEVER, A LOT OF VARIABLES
WOULD HAVE TO PERFECTLY ALIGN FOR THIS TO OCCUR. SO WHILE THE
FORECAST MAY INTRODUCE A MENTION OF A SLIGHT CHANCE (15%) FOR
RAIN/SNOW LATE WEDNESDAY NIGHT INTO THURSDAY MORNING, IT IS
EXTREMELY UNLIKELY YOU'LL SEE ANY IMPACTS BELOW 1500-2000FT - IN
FACT YOU'LL BE LUCKY TO SEE ANYTHING AT ALL.
MOSTLY DRY CONDITIONS RETURN FRIDAY AFTERNOON THROUGH SATURDAY
WITH INLAND HIGH TEMPERATURES IN THE 50S AND LOW TEMPERATURES IN
THE MID 30S. UNCERTAINTY INCREASES IN THE FORECAST LATE SATURDAY
INTO LATE SUNDAY. ENSEMBLE GUIDANCE IS IN HIGH AGREEMENT THAT
THE CLOSED LOW REMNANT FROM THE CURRENT LONGWAVE TROUGH IS
SLATED TO MOVE INLAND ALONG THE CALIFORNIA DURING THIS
TIMEFRAME. 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 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. A BIT MORE OF A NORTHERN TRACK WILL LIKELY KEEP LOW
TEMPERATURES ABOVE FREEZING DUE TO CLOUD COVER, BUT A MORE
SOUTHERN TRACK COULD KEEP THE AREA FROM BEING IMPACTED BY THE
CLOSED 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, LEADING TO INCREASING CONFIDENCE
OF DRY WEATHER LATER MONDAY INTO TUESDAY. -03/99
AVIATION
A FRONTAL SYSTEM ASSOCIATED WITH AN ATMOSPHERIC RIVER
REMAINS STALLED OVER THE REGION THIS AFTERNOON WITH VERY LITTLE
MOVEMENT. BECAUSE IT HAS YET TO SHIFT SOUTHWARD AS MODELS
SUGGESTED, HAVE SEEN A TREND TOWARDS MORE WIDESPREAD IFR
CONDITIONS WITH POCKETS OF LIFR IN PASSING RAIN SHOWERS. VIS HAS
BECOME MUCH LOWER THAN PREVIOUSLY FORECAST WITH VISIBILITY LESS
THAN 2 SM THROUGHOUT THE AREA. BASED ON HOW THIS PATTERN IS
PROGRESSING (OR A LACK THEREOF), WILL SEE MINIMAL CHANGE OVER THE
NEXT 12 HOURS. WHILE MODELS WANT TO ATTEMPT TO CLEAR OR LIFT CIGS
OVERNIGHT, THE AMOUNT OF MOISTURE IN THE ATMOSPHERE COMBINED WITH
A LACK OF MIXING AND LIGHT NORTHERLY WINDS, IT WILL BE QUITE
DIFFICULT TO DO. IN FACT, BASED ON THE OVERALL PATTERN BEGINNING
TO LEAN TOWARDS A MUCH MORE DEGRADED FORECAST THAN PREVIOUSLY
THOUGHT. HOWEVER, THERE REMAINS AROUND A 40% CHANCE THAT SKIES DO
LIFT. IF THEY DO, AND ENOUGH COOLING OCCURS, CANNOT RULE OUT DENSE
FOG.
KPDX AND APPROACHES...IFR CIGS HAVE DOMINATED THE REGION AND BASED
ON AREA PIREPS, THE CLOUD DECK APPEARS TO BE QUITE DENSE. WITH
THIS BEING THE CASE, UNLESS SIGNIFICANTLY DRIER AIR MOVES IN WE
WILL SEE LIMITED IMPROVEMENT. HOWEVER, THE DRIER AIRMASS IS
SITTING JUST TO THE NORTH SO AS THE FRONT SHIFTS SOUTHWARD, THAT
AIR SHOULD MOVE IN. IF THIS DOES OCCUR, AND SKIES IMPROVE, THERE
WILL BE A TREND TOWARDS DENSE FOG DEVELOPMENT DUE TO ENCOURAGED
DIURNAL COOLING. BASED ON ENSEMBLE MODELS, THERE IS AROUND A 30%
CHANCE OF LIFR VIS, AND A 65% CHANCE OF AT LEAST MVFR VIS AFTER
10Z WED. BASED ON THE CURRENT OBSERVATIONS, THERE IS A STRONGER
LEAN TOWARDS MVFR VIS WITH IFR CIG OVERNIGHT. CONFIDENCE REMAINS
LOW AT THIS TIME.-27
MARINE
SEAS AND WINDS HAVE EASED AS THE MAIN FRONTAL BAND HAS
SHIFTED SOUTHWARD. NORTHERLY WINDS PERSIST AROUND 8-13 KT WITH
ISOLATED GUSTS UP TO 20 KT. THESE CONDITIONS HAVE NOT BEEN
WIDESPREAD AND HAVE SLOWLY EASED THROUGH THE AFTERNOON. SEAS TOO
HAVE FALLEN BELOW 8 FT FOR MOST BUOYS WITH MOST SITTING IN THE 5-7
FT AT 10 SECOND RANGE. THESE CONDITIONS WILL PERSIST THROUGH
FRIDAY. 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, WILL SEE WIDESPREAD SEAS RISE TO OR ABOVE 10 FT BUT
THERE IS A LOW PROBABILITY OF SEAS EXCEEDING THAT 10 FT MARK.
-27
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
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