676
FXUS66 KPDT 302219
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
219 PM PST SUN NOV 30 2025
KEY POINTS
1. COLD OVERNIGHT TEMPERATURES WITH PATCHY FOG/FREEZING FOG
2. MOUNTAIN SNOW RETURNS MONDAY MORNING INTO TUESDAY AFTERNOON
3. WIDESPREAD RAIN AND HIGH MOUNTAIN SNOW THURSDAY NIGHT THROUGH THE
WEEKEND
DISCUSSION
CURRENT SATELLITE SHOWS PORTIONS OF THE REGION TO BE
CLEARING OUT WITH ONLY HIGH CLOUDS LINGERING OVERHEAD. HOWEVER, THE
EASTERN MOUNTAINS THROUGH THE NORTHERN BLUES STILL HAVE A STRATUS
DECK OVERHEAD. THE ROUND OF SNOW FROM LAST NIGHT AVERAGED 1 IN HERE
AT THE OFFICE WITH OTHER AREAS REPORTING A SKIFF TO 0.5 INCHES OF
SNOW ON THE GROUND. DRY NORTHERLY FLOW HAS TAKEN OVER TODAY AND WILL
CONTINUE TO USHER IN DRY AND COLD TEMPERATURES THROUGH MONDAY
MORNING.
TODAY THROUGH WEDNESDAY...NORTHERLY FLOW WILL KEEP THE REGION UNDER
COLD AND DRY CONDITIONS. LOW CLOUDS HAVE PERSISTED OVER THE EASTERN
MOUNTAINS AND THE BLUES TODAY MAINLY DUE TO UPSLOPE FLOW. COLD AIR
WILL CONTINUE TO SETTLE OVER THE REGION THROUGH THE OVERNIGHT HOURS
WHICH WILL LEAD TO PATCHY TO AREAS OF FOG/FREEZING FOG OVERNIGHT
INTO THE MORNING THROUGH MANY OF THE VALLEYS, BASINS AND FOOTHILLS OF
THE BLUES AS WELL AS AREAS ALONG THE COLUMBIA RIVER. TEMPERATURES
OVERNIGHT WILL BE BELOW FREEZING ACROSS THE ENTIRE REGION WITH ALL
LOCATIONS, EXCEPT THROUGH THE GORGE AND ISOLATED SPOTS ALONG THE
RIVER, SEEING TEMPERATURES BELOW 32 DEGREES WITH WELL OVER 80%
PROBABILITIES.
MONDAY AFTERNOON AND INTO THE EVENING, MODELS SHOW A SHORTWAVE AHEAD
OF A WEAK TROUGH BEGINNING TO MAKE ITS WAY TOWARDS THE REGION. THE
SHORTWAVE WILL BRING BACK SNOW SHOWERS TO THE WA CASCADES AND ACROSS
THE EASTERN MOUNTAINS AND THE NORTHERN BLUES. 24 HOUR RAW GUIDANCE
HAS 50-80% PROBABILITIES OF 1-3 INCHES ACROSS THE NORTHERN BLUES,
EAGLE CAPS AND HIGHER ELEVATIONS OF THE WA CASCADES MONDAY NIGHT
THOUGH TUESDAY. ZOOMING IN ON THE I-84 CORRIDOR, RAW ENSEMBLES SHOW
50-70% PROBABILITIES OF NEAR 2 INCHES OF SNOW AND ALONG THE I-90
CORRIDOR 30-50% PROBABILITIES OF 0.5-1 INCH OF SNOW.
MODELS SHOW BY TUESDAY NIGHT THE SHORTWAVE WILL HAVE MOSTLY CLEARED
THE REGION ALLOWING NORTHERLY DRY FLOW TO DOMINATE THE REGION AGAIN.
DRY AND COLD TEMPERATURES WILL DOMINATE THE REGION WEDNESDAY AHEAD OF
THE NEXT INCOMING WAVE. TEMPERATURES AGAIN WILL BE BELOW 32 DEGREES
FOR MUCH OF THE REGION WITH ONLY THE GORGE AND ISOLATED AREAS ALONG
THE RIVER SEEING TEMPERATURE AT OR SLIGHTLY ABOVE FREEZING WITH 75-
95% PROBABILITIES.
THURSDAY ONWARDS...MODELS SHOW ANOTHER ROUND OF SHORTWAVES MAKING
THEIR WAY INTO THE REGION BEGINNING THURSDAY THAT WILL ANOTHER ROUND
OF MOUNTAIN SNOW SPREADING TO WIDESPREAD RAIN ACROSS THE LOWER
ELEVATIONS. CLUSTERS DO SHIFT IN PHASE A BIT WITH THE BIGGEST
DISCREPANCY BEING IN THE TIMING OF THE EVENT AS WELL AS AMOUNTS OF
PRECIPITATION EXPECTED. MODELS DO SHOW THE HEAVIEST AMOUNTS OF
PRECIPITATION WILL OCCUR THURSDAY BEFORE SLOWLY TAPERING OFF OVER
THE WEEKEND. SNOW LEVELS WILL BE OVER 4000 FT AND INCREASING TO
ABOVE 6000 FT BEFORE DECREASING TO BELOW 4000 FT SUNDAY. HIGH
ELEVATION SNOW IS EXPECTED, HOWEVER, ALONG THE I-90 AND I-84
CORRIDORS LITTLE TO NO FALL IS EXPECTED WITH THIS SYSTEM WITH
MODERATE CONFIDENCE (60-70%). MUCH OF THE PRECIPITATION WILL FALL AS
RAIN BELOW 4000 FT WITH ONLY SLIGHT CHANCES (15-30%) THROUGH
CENTRAL/NORTH CENTRAL OR, THE LOWER COLUMBIA BASIN OF OR & WA AND 30-
50% CHANCES OF 0.01-0.04 ALONG THE FOOTHILLS. HIGHEST AMOUNTS WILL
BE THROUGH THE MID TO UPPER ELEVATIONS FRIDAY. SATURDAY,
PRECIPITATION LOOKS TO SPILL OVER ALONG THE EASTERN SLOPES OF THE
CASCADES AND FARTHER ALONG THE FOOTHILLS WITH (50-70%) PROBABILITIES
OF THOSE AREAS SEEING BETWEEN 0.01-0.05 INCHES OF RAIN. SUNDAY WILL
SEE DRYER CONDITIONS ACROSS THE LOWER ELEVATIONS WITH ONLY LIGHT
RAIN ACROSS THE EASTERN MOUNTAINS WITH CONTINUED SNOW SHOWERS ALONG
THE HIGHER CRESTS. ALL IN ALL A MODERATE CHANCE (60-70%) OF HAVING A
WET WEEKEND. 90
AVIATION...00Z TAFS
MOST SITES WILL SEE VFR CONDITIONS THIS
EVENING, SAVE FOR ALW AND BDN WHERE LOW CIGS PERSIST, HOWEVER SOME
CLEARING HAS BEEN OBSERVED FOR BOTH SITES THIS AFTERNOON. CONFIDENCE
REMAINS SHAKY ON THE DEVELOPMENT OF LOW CLOUDS AND FOG OVERNIGHT
TONIGHT, AS COLDER AIR MOVING IN COMBINED WITH HIGH CLOUDS MAY
INHIBIT FOG DEVELOPMENT, BUT MADE MENTION OF AT LEAST SCT-BKN LOW
CIGS AT A FEW SITES SINCE HIGH PRESSURE IS MOVING IN, WHICH IS
GENERALLY FAVORABLE FOR FOG AND LOW STRATUS DEVELOPMENT. OTHERWISE,
WINDS WILL REMAIN LIGHT AND TERRAIN-DRIVEN. ANOTHER ROUND OF PRECIP
MAY ARRIVE TO THE FORECAST AREA AROUND THE TAIL-END OF THE PERIOD. 74
PRELIMINARY POINT TEMPS/POPS
PDT 22 38 30 40 / 0 10 40 60
ALW 26 37 31 38 / 0 20 50 70
PSC 25 37 27 39 / 0 10 20 20
YKM 24 38 25 43 / 10 10 10 0
HRI 25 37 28 41 / 0 10 30 40
ELN 22 37 25 43 / 10 20 20 10
RDM 19 49 27 46 / 0 10 10 10
LGD 21 42 31 40 / 0 10 40 80
GCD 21 47 31 43 / 0 10 30 50
DLS 31 42 35 50 / 10 20 20 20
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
SHORT TERM...90
LONG TERM....90
AVIATION...74
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