607
FXUS66 KPDT 272256
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
256 PM PST TUE JAN 27 2026
DISCUSSION
THROUGH THIS EVENING: UPPER LEVEL RIDGING OVER THE
PACNW CONTINUES TO PUSH EAST THIS AFTERNOON, WITH MID TO UPPER
LEVEL CLOUD COVER STARTING TO SPREAD NORTHEAST. THERE HAS BEEN A
FEW BREAKS IN THE CLOUDS TODAY, ALLOWING SOME AREAS OF CENTRAL OR,
COLUMBIA BASIN, AND ADJACENT VALLEYS TO WARM INTO THE UPPER 30S
TO MID 40S. THE REMAINDER OF THE LOWER ELEVATIONS HAVE REMAINED
COOL THROUGH THIS AFTERNOON, OWING TO CLOUD COVER ALOFT AND HAZE
NEAR THE SURFACE, BUT HAVE MANAGED TO WARM ABOVE FREEZING. NOT
EXPECTING MUCH CHANGE IN THESE TEMPERATURE TRENDS THROUGH THE
REMAINDER OF THE DAYLIGHT HOURS, AS THE COLD POOL IMPACTING MOST
OF THE REGION WILL RESULT IN TEMPERATURES QUICKLY DROPPING TO OR
BELOW FREEZING THROUGH THIS EVENING.
TONIGHT THROUGH FRIDAY EVENING: A SERIES OF SHORTWAVE TROUGHS WITH
ATTENDANT SURFACE FRONTS WILL IMPACT THE FORECAST AREA STARTING
TONIGHT, WITH PRECIPITATION CHANCES PERSISTING AT LEAST IN THE
MOUNTAINS THROUGH FRIDAY EVENING. THE FIRST OF THESE SHORTWAVES
WILL LIFT NORTHEAST ACROSS THE PACNW TONIGHT THROUGH WEDNESDAY
MORNING, BRINGING THE HIGHEST PRECIPITATION CHANCES TO THE CASCADE
CREST, WALLOWAS, AND THE NORTHERN BLUES THROUGH MID MORNING
WEDNESDAY. WHILE THE MOUNTAINS WILL SEE LIGHT TO MODERATE SNOW
ACCUMULATIONS, THE MAIN PRECIPITATION CONCERNS WILL REVOLVE
AROUND A WINTRY MIX IN THE LOWER ELEVATIONS, SPECIFICALLY THE
POTENTIAL FOR LIGHT FREEZING RAIN, AS FORECAST MODELS INDICATE A
WARM TONGUE EXTENDING ACROSS PORTIONS OF THE LOWER ELEVATIONS.
CONFIDENCE IS MODERATE (50-75%) THAT POCKETS OF CENTRAL OR, THE OR
COLUMBIA BASIN, AND ADJACENT BLUE MOUNTAIN FOOTHILLS WILL SEE
LIGHT FREEZING RAIN MIX WITH RAIN, WHILE A MIX OF SNOW AND
FREEZING RAIN IS FAVORED IN THE WA COLUMBIA BASIN AND ADJACENT
VALLEYS. SNOW ACCUMULATIONS IN THE AFOREMENTIONED AREAS WILL
AMOUNT TO A DUSTING, WHILE FREEZING RAIN ACCUMULATIONS ACROSS ALL
THE LOWER ELEVATIONS WILL BE UNDER 0.05". THAT SAID, GLOBAL AND
HIRES ENSEMBLES ARE IN DISAGREEMENT IN IMPACTED LOCATIONS AND
ACCUMULATIONS, OWING TO POOR HANDLING OF THE PERSISTENT SURFACE
COLD AIR POOL, CLOUD COVER ALOFT, AND STRENGTH OF THE INCOMING
FRONT/SHORTWAVE. AS SUCH, THIS HAS RESULTED IN LOW CONFIDENCE
(15-20%) IN WIDESPREAD FREEZING RAIN IMPACTS.
LIGHT SNOW WILL CONTINUE ACROSS THE CASCADE CREST AND UPPER EAST
SLOPES THROUGH WEDNESDAY, WITH CHANCES INCREASING AGAIN WEDNESDAY
NIGHT THROUGH THURSDAY AS THE NEXT SHORTWAVE IMPACTS THE REGION.
THIS NEXT SYSTEM IS EXPECTED TO HAVE BETTER MOISTURE SUPPORT,
WHICH TRANSLATES TO HIGHER CHANCES OF LOWER ELEVATION
PRECIPITATION. ENSEMBLE AND NBM GUIDANCE IS MOSTLY IN FAVOR OF
MOSTLY RAIN IN THE LOWER ELEVATIONS WITH POCKETS OF FREEZING RAIN
ALONG THE LOWER PORTIONS OF THE CASCADE EAST SLOPE VALLEYS. THAT
SAID, THE COLDEST ENSEMBLE MEMBERS (MOSTLY MADE UP OF THE CANADIAN
ENSEMBLE SUITE) KEEP THE COLD AIR POOL IN PLACE ACROSS THE LOWER
ELEVATIONS, RESULTING IN MORE WIDESPREAD FREEZING RAIN CHANCES
WEDNESDAY NIGHT. WHILE A MAJORITY OF MODELS BRING WARMER
CONDITIONS, THEY HAVE ALSO CONTINUED TO HANDLE THE COLD POOL
POORLY OVER THE PAST FEW WEEKS, SO FORECASTER CONFIDENCE IN
PRECIPITATION TYPE IS LOW-MOD (15-35%) FOR WEDNESDAY NIGHT.
CONFIDENCE IN EITHER SOLUTION WILL GROW TOMORROW DEPENDING ON HOW
TEMPERATURES TRENDS SHAKE OUT IN THE LOWER ELEVATIONS.
A RIDGE WILL BRIEFLY AMPLIFY OVER THE REGION THURSDAY, BUT
FLATTEN AS THE LAST OF THE SERIES OF SHORTWAVES SLIDES ACROSS THE
PACNW THURSDAY NIGHT. OVERALL, GUIDANCE IS IN FAVOR OF WARMING
CONDITIONS ACROSS MUCH OF THE PACNW, WITH SNOW LEVELS RISING TO
ABOVE 5.5KFT TO 6KFT THURSDAY NIGHT. THAT SAID, THIS LAST SYSTEM
WILL HAVE A WEAK MOISTURE PLUME THAT WILL RESULT IN THE BEST
PRECIPITATION CHANCES ACROSS THE CASCADE CREST WITH A TRACE AT
BEST EAST OF THE CREST. BY FRIDAY EVENING, UPPER LEVEL RIDGING
WILL REDEVELOP OVER THE PACNW, RESULTING IN DRYING CONDITIONS.
FRIDAY NIGHT THROUGH MONDAY: ENSEMBLE GUIDANCE IN GOOD AGREEMENT
OF STARTING THE WEEKEND OFF WITH DRY AND MILD CONDITIONS ACROSS
THE FORECAST AREA AS AN UPPER RIDGE PARKS ACROSS THE REGION
THROUGH SUNDAY MORNING. BY SUNDAY AFTERNOON, A SHORTWAVE WILL
ARRIVE TO THE PACNW AND LIFT NORTHEAST THROUGH MONDAY, BRINGING
WITH IT A CHANCE OF LIGHT PRECIPITATION ACROSS THE MOUNTAINS AND
LOWER ELEVATIONS OF THE FORECAST AREA(CONFIDENCE 30-60%).
LAWHORN/82
AVIATION...00Z TAFS
VFR CONDITIONS CONTINUES THROUGH THE
REMAINING TAF PERIOD FOR MOST SITES. EVEN WITH LIMITED MOISTURE
AND THE LASTING COLDER AIR, LIGHT FREEZING RAIN IS POTENTIAL FOR
KPDT/KYKM/KALW/KPSC (30% PROBABILITY) TONIGHT THROUGH WEDNESDAY
MORNING. THAT SAID, THIS LED US TO ISSUING AN AIRPORT WEATHER
ADVISORY FOR KPDT. LOW CONFIDENCE (<30%) FOR AN AIRPORT WEATHER
WARNING FOR KPSC AT THIS TIME, BUT WILL MONITOR FOR POTENTIAL
FREEZING RAIN. VSBY FOR KALW HAS IMPROVED, BUT NOW WITH HAZE
LINGERING UNTIL LATER ON TODAY. LOW CLOUD DECKS WILL CONTINUE
ACROSS KALW AS WELL INTO THIS LATE EVENING, THOUGH MAY RETURN
WEDNESDAY MORNING. GUIDANCE IS ALSO HINTING FOG LATER THIS EVENING
FOR KALW, BUT LEFT IT OUT SINCE CONFIDENCE LEVEL IS LOW GIVEN THE
UPCOMING SYSTEM. HOWEVER, IT DOES DEPEND ON THE STRENGTH ON THE
SYSTEM. WINDS WILL REMAIN LESS THAN 10KTS. FEASTER/97
PRELIMINARY POINT TEMPS/POPS
PDT 25 46 35 52 / 30 30 20 40
ALW 27 43 37 50 / 30 50 20 60
PSC 25 43 34 48 / 20 20 30 50
YKM 24 38 32 43 / 20 20 40 60
HRI 24 43 34 50 / 20 20 30 40
ELN 23 35 31 39 / 20 30 60 80
RDM 23 45 32 50 / 20 10 20 20
LGD 30 45 32 43 / 40 50 10 50
GCD 27 45 32 45 / 50 20 20 50
DLS 28 42 37 46 / 50 50 80 80
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
DISCUSSION...82
AVIATION...75
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