066
FXUS66 KPDT 301123
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
323 AM PST SUN NOV 30 2025
DISCUSSION
SNOW IS TAPERING OFF OVER THE BLUE MOUNTAINS AS THE
UPPER-LEVEL LOW THAT INDUCED LIGHT SNOW ACROSS MUCH OF CENTRAL TO
EASTERN OREGON AND SOUTHEAST WASHINGTON EXITS TO THE SOUTHEAST.
IN ITS WAKE, CONFIDENCE IS HIGH (90 PERCENT) THAT WIDESPREAD LOW
STRATUS ACCOMPANIED BY AT LEAST PATCHY DENSE FOG WILL CONTINUE
THROUGH THIS MORNING. DRY CONDITIONS ARE THEN ANTICIPATED INTO
MONDAY AFTERNOON AS UPPER-LEVEL RIDGING NOSES INTO THE PACIFIC
NORTHWEST. THIS WILL LIKELY (70 PERCENT CONFIDENCE) RESULT IN
ANOTHER ROUND OF STRATUS AND FOG FOR BASIN AREAS TONIGHT THROUGH
MONDAY MORNING.
LOOKING AHEAD, ANOTHER SHORTWAVE EMBEDDED WITHIN NORTHWESTERLY
FLOW ALOFT IS ADVERTISED FOR LATE MONDAY THROUGH TUESDAY NIGHT.
SNOW CHANCES ARE REDUCED ACROSS THE COLUMBIA BASIN AND BLUE
MOUNTAIN FOOTHILLS (10-30 PERCENT CHANCE OF MEASURABLE SNOW PER
NBM GUIDANCE) COMPARED TO THE ONE THAT BROUGHT LOW-ELEVATION
SNOWFALL TO THE BLUE MOUNTAIN FOOTHILLS YESTERDAY EVENING INTO
EARLY THIS MORNING, BUT A BETTER MOISTURE TAP SHOULD FACILITATE
SLIGHTLY BETTER CHANCES (15-30 PERCENT) OF ADVISORY-LEVEL SNOW
FOR THE BLUE MOUNTAINS. ENSEMBLE GUIDANCE IS NOW ALSO SUGGESTING
SOME LOCALLY BREEZY WESTERLY WINDS THROUGH THE CASCADES GAPS ON
TUESDAY.
BY THE END OF THE WEEK, ENSEMBLE SOLUTIONS BEGIN TO DIVERGE WITH
REGARD TO PATTERN DETAILS, SPECIFICALLY WHETHER UPPER-LEVEL
RIDGING WILL PERSIST ON FRIDAY (~60 PERCENT OF MEMBERS) OR A MORE
ZONAL PATTERN (~40 PERCENT OF MEMBERS) WILL BEGIN. BY SATURDAY, A
TRANSITION TO A MORE ZONAL UPPER-LEVEL PATTERN IS PRESENT AMONG
ALL ENSEMBLE CLUSTERS. AS FAR AS TANGIBLE WEATHER, THIS WOULD
RESULT IN WARMER, WETTER, BREEZIER CONDITIONS. OF NOTE, EFI
VALUES RANGING FROM 0.5-0.8 ACROSS THE COLUMBIA PLATEAU ARE
POINTING TO DECENT ENSEMBLE AGREEMENT IN WINDY CONDITIONS RELATIVE
TO MODEL CLIMATOLOGY.
AVIATION...06Z TAFS...PREVIOUS DISCUSSION
CEILINGS WILL REMAIN
IN THE LIFR AND IFR CATEGORIES FOR MANY OF THE TERMINALS OVERNIGHT
AS THE AREA RECOVERS FROM AS WEAK UPPER TROUGH OVERSPREADING A
COLD SURFACE AIRMASS. DLS AND YKM WILL BE MVFR OR BETTER. FARTHER
EASTWARD PDT AND ALW HAD LINGERING -SN AND LIMITED VISIBILITY TO
AROUND 1 MILE AS A RESULT. THIS WILL CONTINUE FOR A FEW MORE
HOURS. PSC WAS A LITTLE WARMER RESULTING IN THE RAIN PRECIPITATION
TYPE. TO THE WEST, BDN AND RDM HAVE LAV FORECASTS THAT MAINTAIN
THE STRATUS OVERNIGHT WITH LITTLE HOPE OF ANY IMPROVEMENT UNTIL
AROUND 12Z AND AFTERWARD. RUSSELL/71
PRELIMINARY POINT TEMPS/POPS
PDT 37 22 39 29 / 0 0 0 40
ALW 36 25 37 31 / 0 0 10 50
PSC 39 24 37 27 / 0 0 0 30
YKM 41 24 38 26 / 0 0 0 20
HRI 38 25 37 29 / 0 0 0 30
ELN 39 22 37 26 / 0 10 10 20
RDM 40 19 49 27 / 0 0 0 10
LGD 39 21 42 31 / 0 0 0 40
GCD 38 21 46 31 / 0 0 0 30
DLS 44 30 42 35 / 0 0 10 30
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
DISCUSSION...86
AVIATION...71
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