764
FXUS66 KPQR 240605 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1005 PM PST MON FEB 23 2026
...UPDATED PUBLIC, AVIATION, AND WATCHES/WARNINGS/ADVISORIES
SECTIONS...
SYNOPSIS
A WEAK ATMOSPHERIC RIVER EVENT WILL KEEP CONDITIONS
SOGGY INTO TUESDAY ALTHOUGH WEATHER RELATED IMPACTS APPEAR
RATHER MINOR DURING THIS PERIOD. WEDNESDAY INTO THE WEEKEND,
THE WEATHER PATTERN APPEARS FAIRLY BENIGN WHILE TRENDING DRIER,
AT LEAST FOR THE INLAND VALLEYS. CONDITIONS LIKELY REMAIN
WITHIN OUR TYPICAL CLIMATOLOGICAL NORMS LATE WEEK INTO THE,
WEEKEND BUT FORECAST UNCERTAINTY BEGINS TO NOTICEABLY INCREASE
LATE SATURDAY/SUNDAY ONWARD.
EVENING UPDATE
A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR
ELEVATIONS ABOVE 1000 FEET IN THE UPPER HOOD RIVER VALLEY THROUGH 10
AM TUESDAY. SURFACE OBSERVATIONS AS OF LATE MONDAY EVENING SHOW
TEMPERATURES RANGING BETWEEN 31 AND 34 DEGREES, COLDEST ABOVE 1000
FEET ELEVATION. WEBCAMS AND PUBLIC REPORTS INDICATE THAT THERE IS AT
LEAST A RAIN/SNOW MIX OR LIGHT SNOW IN THE PARKDALE AREA. TRIPCHECK
OBSERVATIONS ALSO INDICATE POTENTIAL TRAFFIC SLOW-DOWN ON HIGHWAY 34
BETWEEN ODELL AND PARKDALE. CONSIDERING THAT COLD AIR COMMONLY GETS
TRAPPED HERE FOR EXTENDED PERIODS OF TIME AND A STALLED FRONT WILL
MAINTAIN PRECIPITATION THROUGH TUESDAY MORNING, WENT AHEAD AND
ISSUED THE ADVISORY. LOW CONFIDENCE WITH EXACT SNOW AMOUNTS, BUT
COULD SEE ANYWHERE BETWEEN A TRACE AND 1 INCH FOR THE HIGHEST
ELEVATIONS OF THE UPPER HOOD RIVER VALLEY. THOSE TRAVELING IN THIS
AREA SHOULD USE EXTRA CAUTION THROUGH TUESDAY MORNING. -10
SHORT TERM...MONDAY AFTERNOON THROUGH WEDNESDAY
VISIBLE
SATELLITE IMAGERY MONDAY AFTERNOON CLEARLY DEPICTS THE MOISTURE
STREAM ASSOCIATED WITH THE MODERATE ATMOSPHERIC RIVER (AR)
IMPACTING THE PACNW STRETCHING FROM THE TROPICS EAST OF HAWAII
ALL THE WAY INTO WASHINGTON, OREGON, AND NORTHERN CALIFORNIA.
THIS MOISTURE IS BEING STREAMED THROUGH THE EASTERN PACIFIC BY A
LONGWAVE TROUGH, WHICH IS ALSO CLEARLY VISIBLE ON SATELLITE
IMAGERY. THIS TROUGH WILL CONTINUE PUMPING MOISTURE INTO THE
REGION THROUGH TUESDAY. AT THE SURFACE, A QUASI-STATIONARY FRONT
HAS STALLED THROUGH CENTRAL OREGON THIS AFTERNOON AND WILL
REMAIN IN THIS GENERAL AREA THROUGH TOMORROW MORNING BEFORE IT
FINALLY SHIFTS EAST. STEADY STRATIFORM RAIN WILL CONTINUE ACROSS
NW OREGON AND SW WASHINGTON INTO TOMORROW MORNING, BECOMING
SHOWERY IN THE WAKE OF THE SHIFTING FRONT INTO THE EVENING
HOURS. AS OF 2 PM PST, THE HIGHEST 24 HOUR OBSERVED RAIN TOTALS
STRETCH FROM THE CENTRAL OREGON COAST SOUTH OF LINCOLN CITY TO
COOS BAY TO THE NORTHEAST FROM THE NORTH OREGON CASCADES
THROUGH THE LINN COUNTY CASCADES WITH 1.25-2.5 INCHES IN THE
CENTRAL AND SOUTHERN WILLAMETTE VALLEY AND 1.5-2 INCHES FOR THE
COAST, COAST RANGE, AND CASCADES. THROUGH 4 PM PST TUESDAY, AN
ADDITIONAL 0.5-1.75 INCH OF RAIN IS EXPECTED ACROSS THE INTERIOR
LOWLANDS, 0.3-1.5 INCH ALONG THE COAST AND COAST RANGE, AND
1-2.5 INCHES ACROSS THE CASCADES. THE BAND OF HEAVIEST
PRECIPITATION HAS SHIFTED SLIGHTLY SOUTH THIS AFTERNOON WITH THE
HEAVIEST PRECIPITATION EXPECTED SOUTH OF THE OREGON BORDER, AND
ESPECIALLY IN LANE COUNTY WHERE AN ADDITIONAL 1.25-2 INCHES
ALONE IS EXPECTED, LOCALLY UP TO 2.5 INCHES IN THE CASCADES.
RIVER OBSERVATIONS ACROSS THE AREA SHOW STEEP RISES ON MOST
RIVERS IN NW OREGON TODAY, THOUGH SINCE RIVERS WERE WELL BELOW
FLOOD STAGE LEADING INTO THIS EVENT, THERE IS STILL LESS THAN 5%
CHANCE OF RIVERS REACHING FLOOD STAGE. WARM RAIN FALLING ON
EXISTING SNOW AND CAUSING SNOW TO MELT IS MOST CERTAINLY AIDING
IN RISING RIVER LEVELS. THIS ALONG WITH THE STEADY RAIN AMOUNTS
COULD STILL CAUSE LOCALIZED IMPACTS SUCH AS QUICK RISES OR
LOCALIZED FLOODING ON SMALL CREEKS AND STREAMS AS WELL AS
PONDING OF WATER ON ROADWAYS AND IN LOW-LYING AREAS. SNOW LEVELS
ROSE QUICKLY LATE THIS MORNING INTO THIS AFTERNOON TO ABOVE PASS
LEVEL, AND THEY SHOULD REMAIN ABOVE PASS LEVEL THROUGH TUESDAY.
ADDITIONALLY, WIND IS NOT A CONCERN WITH THIS EVENT.
TUESDAY NIGHT INTO WEDNESDAY, THE LONGWAVE TROUGH PRODUCING THE
CURRENT AR ACTUALLY CUTS OFF INTO A CLOSED LOW AND MOVES WEST
INTO THE PACIFIC WHILE FLOW OVER THE PACNW BECOMES MORE ZONAL.
SCATTERED SHOWERS WILL CONTINUE THROUGH WEDNESDAY AS A WEAK
SHORTWAVE MOVES SOUTHEAST THROUGH WA AND OR. MOST AREAS ARE
EXPECTED TO DRY OUT BY LATE WEDNESDAY WITH PRECIPITATION CHANCES
MAINLY LIMITED TO THE FAR NORTH OREGON COAST, COAST RANGE, AND
CASCADES AND SW WASHINGTON. -03
LONG TERM...THURSDAY THROUGH SUNDAY
COLDER AIR IS EXPECTED
TO BE FUNNELED INTO THE PACNW BEHIND WEDNESDAY'S SHORTWAVE.
THIS ALONG WITH CLEARING SKIES 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 30-50% CHANCE FOR
THE SW WASHINGTON LOWLANDS. FOR LOW ELEVATION LOCATIONS THAT
STILL HAVE PRECIPITATION CHANCES DURING THIS TIME, THERE IS THE
POTENTIAL FOR SOME FLURRIES TO MIX WITH RAIN OR RAIN TO TURN A
LITTLE SLUSHY. HOWEVER, THERE IS A LESS THAN 5% CHANCE OF ANY
ACCUMULATING SNOW.
ENSEMBLE GUIDANCE INDICATES ZONAL FLOW RETURNS FOR THURSDAY
THROUGH THE WEEKEND. LOW PRECIPITATION CHANCES CONTINUE ACROSS
THE AREA EACH DAY, MAINLY OVER THE TERRAIN, WITH LIMITED
ACCUMULATION EXPECTED. THE CLOSED LOW REMNANT FROM THE CURRENT
LONGWAVE TROUGH IS SLATED TO MOVE BACK EAST TOWARDS THE WEST
COAST LATE WEEKEND TO EARLY NEXT WEEK. MOST ENSEMBLE MEMBERS
SUGGEST IT WILL MOVE INLAND ALONG THE CA COAST, BUT EXACTLY
HOW FAR NORTH OR SOUTH IS UNCERTAIN. THIS UNCERTAINTY IS PART
OF THE REASON FOR THE LOW PRECIPITATION CHANCES.
HOWEVER, THE JET STREAM ALONG THE ZONAL FLOW IS EXPECTED TO DIP
SOUTH INTO CENTRAL OR, WHICH WOULD ALLOW FOR COLDER AIR TO
IMPACT THE AREA ONCE AGAIN SATURDAY NIGHT AND SUNDAY NIGHT.
THERE'S A 30-60% CHANCE OVERNIGHT TEMPERATURES FALL BELOW
FREEZING AGAIN EACH NIGHT FOR THE LOWLANDS OUTSIDE OF THE
PORTLAND METRO AREA. SIMILAR TO THURSDAY MORNING, A RAIN/SNOW
MIX MAY SHOW UP IN THE FORECAST FOR LOWER ELEVATIONS THAT HAVE A
CHANCE OF PRECIPITATION, BUT THERE IS LESS THAN 5% CHANCE OF
ACCUMULATING SNOW. -03
AVIATION
RADAR IMAGERY AS OF LATE MONDAY EVENING DEPICTS
WIDESPREAD RAIN AS A STALLED FRONT REMAINS OVER THE REGION. HIGH
CONFIDENCE (>90% CHANCE) FOR AT LEAST MVFR CIGS ACROSS THE MAJORITY
OF TERMINALS TONIGHT AND THROUGH THE REMAINDER OF THE TAF PERIOD. AN
EXCEPTION IS KAST, WHERE CIGS WILL TREND VFR AS THE HEAVIEST RAIN IS
FURTHER SOUTH. THERE IS ALSO A 40-70% CHANCE EVERYWHERE ELSE FOR IFR
CIGS THROUGH THE TAF PERIOD, WITH THE HIGHEST CHANCES (60-70%)
ACROSS THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY. MODERATE RAIN MAY
RESULT IN VIS REDUCTIONS TO 3-5 SM AT ANY GIVEN TERMINAL. AFTER 18Z
TUE, RAIN WILL DECREASE AND TRANSITION TO SHOWERS. DRIER CONDITIONS
RETURN IN THE LATE EVENING. EASING PRESSURE GRADIENTS KEEP WINDS
UNDER 10 KT ACROSS THE AREA. EASTERLY WINDS ALONG THE COAST AND
NORTHERLY WINDS INLAND TURN MORE WESTERLY/VARIABLE TUESDAY AFTERNOON.
KPDX AND APPROACHES...PREDOMINATELY LOW-END MVFR CIGS (1-2 KFT)
THROUGH THE TAF PERIOD WITH RAIN. 30-50% CHANCE FOR IFR CIGS THROUGH
15Z TUE. RAIN TURNS MORE SHOWERY IN THE AFTERNOON.
VARIABLE WINDS AROUND 5 KT OR LESS. -10
MARINE
SEAS AND WINDS CONTINUE TO TREND DOWN TODAY AND THROUGH
THE MIDDLE OF THE WEEK. SEAS REMAIN STEEP THROUGH TONIGHT WITH A
HAZARDOUS SEAS WARNING REMAINING IN EFFECT UNTIL 7 PM TODAY BEFORE
TRANSITION TO A SMALL CRAFT ADVISORY WHICH IS IN EFFECT UNTIL 10
AM TUESDAY. THE PATTERN IS EXPECTED TO REMAIN BENIGN THROUGH
THURSDAY BEFORE A WNW SWELL ENTERING THE WATERS FRIDAY MORNING
PUSHES SEAS TO AROUND 10 FEET WITH A PERIOD IN THE MID TEENS. -19
PQR WATCHES/WARNINGS/ADVISORIES
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST TUESDAY FOR ORZ121.
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 10 AM PST TUESDAY FOR PZZ210-251>253-
271>273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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