078
FXUS66 KPDT 262235
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
235 PM PST WED NOV 26 2025
DISCUSSION
TODAY THROUGH FRIDAY: SATELLITE AND RADAR IMAGERY
SHOW A WARM FRONT BOUNDARY ACROSS THE NORTHERN TIER OF OR THIS
AFTERNOON, WITH LIGHT RAIN BEING OBSERVED FROM THE GORGE SOUTH TO
MADRAS, AS WELL AS ACROSS THE OR CASCADE CREST.
THE WARM FRONT BOUNDARY WILL GRADUALLY CONTINUE TO LIFT NORTH AND
EAST THROUGH TONIGHT, WITH LIGHT RAIN AND HIGH MOUNTAIN SNOW
DEVELOPING BEHIND THE BOUNDARY. IN ADDITION TO RAIN/SNOW, SMALLER
VALLEYS ALONG THE WA CASCADE EAST SLOPES MAY SEE VERY LIGHT
FREEZING RAIN DEVELOP THIS EVENING AND TONIGHT AS THE WARMER
AIRMASS INITIALLY EXTENDS OVER THESE AREAS.
THANKSGIVING DAY, A COLD FRONT THEN AN ASSOCIATED VERTICALLY
STACKED LOW PRESSURE SYSTEM WILL SWING INTO THE PACNW, BRINGING
WITH IT A ROUND OF LIGHT RAIN AND MOSTLY A RAIN/SNOW MIX ABOVE
5KFT IN THE MOUNTAINS (MAINLY SNOW ABOVE 6-6.5KFT). THE LOW WILL
EXIT THE REGION BY FRIDAY AFTERNOON, WITH DRYING CONDITIONS
SETTING UP AS REMNANTS OF A RIDGE SLIDE SOUTHEAST ACROSS THE
REGION LATE FRIDAY.
SNOW ACCUMULATIONS THROUGH FRIDAY WILL BE VERY LIGHT AT PASS
LEVEL, WITH THE CHANCES OF 1 INCH OF SNOWFALL LESS THAN 10% AT
SNOQUALMIE AND SANTIAM PASSES, ~15% OVER THE NORTHERN BLUES, AND
ONLY A 30% AT WHITE PASS.
SATURDAY THROUGH SUNDAY: ENSEMBLE CLUSTER SOLUTIONS ARE IN GOOD
AGREEMENT THAT A SHORTWAVE TROUGH WILL DIVE DOWN THE BACKSIDE OF
RIDGING IN THE NORTHEAST PACIFIC ON SATURDAY, BUT THAT'S ABOUT
WHERE THE AGREEMENT ENDS. ENSEMBLE CLUSTER MEMBERS (ECMWF, GFS,
CANADIAN ENSEMBLE SUITES) ARE IN DISAGREEMENT IN WHETHER THE
TROUGH ARRIVES TO THE REGION SATURDAY MORNING OR SATURDAY
EVENING, AND WHETHER THERE WILL BE WIDESPREAD LIGHT SNOW, OR THE
LIGHT SNOW WILL BE LIMITED TO CENTRAL OR AND THE BLUE MOUNTAIN
FOOTHILLS. AS TO HOW LIGHT THE SNOW MAY BE IN THE LOWER
ELEVATIONS, THE NBM IS ONLY SHOWING A 10-25% CHANCE OF 0.1 INCHES
OF SNOW ACROSS THE BLUE MOUNTAIN FOOTHILLS, CENTRAL OR, KITTITAS
VALLEY, AND RIDGES AROUND YAKIMA VALLEY. MEANWHILE, CHANCES IN THE
MOUNTAIN ZONES ONLY REACH 50% THROUGH SUNDAY MORNING. OVERALL,
CONFIDENCE IS MODERATE (45-65%) THAT PRECIPITATION WILL REMAIN
LIGHT AS THIS SYSTEM IMPACTS THE FORECAST AREA, HOWEVER,
CONFIDENCE PRECIP TYPE AND TIMING IS LOW (15-30%) GIVEN THE TIMING
DIFFERENCES AMONGST ENSEMBLE SOLUTIONS, AND DETERMINISTIC
GUIDANCE FOR THAT MATTER.
BY SUNDAY AFTERNOON, THERE IS GOOD CONSENSUS THAT DRY, COLD
CONDITIONS WILL RETURN TO THE FORECAST AREA AS THE SHORTWAVE
TROUGH EXITS TO THE SOUTHEAST AND RIDGING OFFSHORE PLACES THE
REGION UNDER A NORTHERLY FLOW ALOFT. DRY CONDITIONS UNDER THE
NORTHERLY FLOW WILL CONTINUE INTO MONDAY, WITH SUNDAY NIGHT LOW
TEMPERATURES IN THE MID 20S IN THE LOWER ELEVATIONS (CONFIDENCE
35-60%).
MONDAY THROUGH TUESDAY: GOOD AGREEMENT AMONGST ENSEMBLE SOLUTIONS
CONTINUES INTO EARLY NEXT WEEK, AS ENSEMBLE MODEL GUIDANCE DEPICTS
THE UPPER RIDGE OFFSHORE FLATTENING AS A TROUGH SWINGS UP AND OVER
INTO THE PACNW (CONFIDENCE 40-55%). THIS SYSTEM WILL BRING ANOTHER
ROUND OF LIGHT SNOW TO THE MOUNTAINS(CONFIDENCE 30-50%), THOUGH
CONFIDENCE IS LOW (15-20%) IN WHETHER THE LOWER ELEVATIONS WILL
SEE ANY OF PRECIPITATION WITH THIS SYSTEM. LAWHORN/82
AVIATION...00Z TAFS
VARIABLE CONDITIONS CONTINUE AS LOW CIGS
PERSIST ACROSS PDT, PSC, ALW, DLS, AND YKM. ONLY BDN AND RDM REMAIN
VFR THIS AFTERNOON, HOWEVER THAT COULD CHANGE AS ANOTHER ROUND OF
LIGHT RAIN MAKES ITS WAY THROUGH THE FORECAST AREA TONIGHT. RAIN IS
EXPECTED TO BE LIGHT, BUT LIGHT WINDS COMBINED WITH MOISTURE WILL
MAKE CONDITIONS IDEAL FOR LOW CLOUDS AND FOG TO REDEVELOP OR PERSIST
HEADING INTO TOMORROW MORNING. ANOTHER SYSTEM IS THEN EXPECTED TO
MOVE THROUGH THANKSGIVING MORNING, PROVIDING FOR ANOTHER CHANCE OF
LIGHT RAIN. AGAIN, RAIN WILL BE LIGHT, AND IS EXPECTED TO CEASE BY
THE LATE AFTERNOON, HOWEVER, CONDITIONS WILL STILL BE FAVORABLE FOR
MVFR CIGS OR WORSE. BDN AND RDM, HOWEVER, ARE LARGELY EXPECTED TO
REMAIN VFR THROUGH THE PERIOD, ESPECIALLY WITH WINDS FORECAST TO
PICK UP TOMORROW AFTERNOON FOR BOTH SITES.
CONFIDENCE IS HIGH (90-100%) IN SITES OUTSIDE OF RDM/BDN SEEING AT
LEAST MVFR CONDITIONS THIS PERIOD, WITH CONFIDENCE MODERATE TO HIGH
(50-60%) IN LOW CIGS / FOG REDEVELOPING OVERNIGHT TONIGHT INTO EARLY
TOMORROW MORNING. 74
PRELIMINARY POINT TEMPS/POPS
PDT 34 49 37 46 / 60 40 70 70
ALW 37 49 38 44 / 60 60 90 80
PSC 35 46 36 49 / 60 60 80 50
YKM 36 44 36 50 / 70 80 80 20
HRI 36 47 37 48 / 60 40 70 60
ELN 32 42 32 46 / 60 90 90 20
RDM 27 58 31 51 / 0 10 20 10
LGD 35 49 35 44 / 60 20 70 80
GCD 33 55 34 46 / 20 10 30 50
DLS 41 49 42 52 / 70 80 90 60
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
SHORT TERM...82
LONG TERM....99
AVIATION...74
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