544
FXUS66 KPDT 251720
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
920 AM PST SUN JAN 25 2026
.UPDATED AVIATION.
AVIATION...18Z TAFS
VFR CONDITIONS PREVAIL FOR THE PERIOD,
EXCEPT IN DLS AND ALW. CURRENTLY HAVE ISOLATED FOG/LOW STRATUS
DEVELOPMENT OVER THESE TWO SITES, BRINGING IFR/LIFR CONDITIONS
WITH QUARTER MILE FOG AND <1000 FOOT CEILINGS. CURRENTLY EXPECTING
IT TOO LAST FOR ANOTHER HOUR OR SO BEFORE DAYTIME MIXING DISPERSES
THE OBSCURE CONDITIONS. SOME GUIDANCE HINTS AT ALW RE-ENTERING
IFR/LIFR THROUGH TOMORROW NIGHT BUT NOT TOO CONFIDENT AT THIS TIME
(<20 PERCENT CHANCE) BUT WILL RE-EVALUATE FOR THE 00Z TAFS.
OTHERWISE, WINDS LIGHT AND VARIABLE.
PREV DISCUSSION
/ISSUED 306 AM PST SUN JAN 25 2026/
KEY POINTS...
1. A HIGH PRESSURE RIDGE WILL DOMINATE THROUGH MID-WEEK
2. LOW LEVEL STRATUS LIKELY RETURN SUNDAY NIGHT/MONDAY MORNING
3. AN UPPER LEVEL SYSTEM MID-WEEK WILL BRING BACK MOUNTAIN
PRECIPITATION.
DISCUSSION...CURRENT SATELLITE SHOWS CLEAR SKIES WITH ONLY A FEW
LINGERING HIGH CLOUDS OVER THE CASCADES. THIS HAS LEAD TO VERY COLD
TEMPERATURES ACROSS THE REGION TONIGHT AS THERE ARE NO CLOUDS TO
TEMPER THE TEMPERATURES. GROUND OBSERVATIONS SHOW ALL LOCATIONS TO
BE BELOW FREEZING THIS MORNING WITH MODELS SHOWING HIGH TEMPERATURES
TODAY REMAINING WELL BELOW CLIMATOLOGICAL NORMAL. IN HOUSE GUIDANCE
SHOWS TEMPERATURES TODAY TO BE ANYWHERE FROM 5 TO 15 DEGREES BELOW
SEASONAL NORMAL WITH NBM HAVING HIGHS IN THE UPPER 20S TO LOW 30S
REGION WIDE WITH ONLY A FEW AREAS ALONG FAR SOUTHERN CENTRAL OR AND
THE EASTERN MOUNTAINS SEEING HIGH 30S TO LOW 40S (60-80% CONFIDENCE).
MODELS CONTINUE TO SHOW THE LEADING EDGE OF THE UPPER LEVEL HIGH TO
BE TO THE WEST OF THE CASCADES AND STEADILY MOVING EASTWARD. BY
MONDAY MORNING THE HIGH SHOULD BE OVER THE CASCADES AND THE HREF
ENSEMBLES SHOW LOW LEVEL STRATUS CLOUDS BEGINNING TO REFORM SUNDAY
AND INCREASING THOUGH THE DAY (50-70% CONFIDENCE). MODELS SHOW THE
UPPER LEVEL RIDGE TO LINGER OVER THE REGION THROUGH WEDNESDAY AHEAD
OF THE NEXT UPPER LEVEL SYSTEM.
MODELS ARE IN FIRM AGREEMENT WITH THE UPPER LEVEL TROUGH DIGGING
INTO THE PACNW BY WEDNESDAY NIGHT. HOWEVER, CLUSTERS SHOW THE MODELS
TO DIFFER IN THE TIMING OF THE ONSET OF THE INCOMING MOUNTAIN
PRECIPITATION AS WELL AS PRECIPITATION AMOUNTS. AS OF NOW, THE NBM
SHOW A 48 HOUR SNOWFALL OF 0.20-0.40 INCHES ALONG SNOQUALMIE PASS
AND TOLLGATE IN THE BLUES WITH HIGHEST CONFIDENCE ALONG SNOQUALMIE
AT 40-50% AND 25-35 FOR TOLLGATE TUESDAY NIGHT THROUGH THURSDAY
NIGHT. THEREAFTER, NBM SHOWS LITTLE TO NO SNOW ACCUMULATIONS,
HOWEVER, RAIN ACCUMULATIONS OF 0.01-0.05 INCHES ALONG THE EAST SLOPES
OF THE CASCADES AND THE NORTHERN BLUES (50-60%) WITH 30% CHANCES OF
SNOQUALMIE SEEING UP TO 0.5 INCHES OF PRECIPITATION. THIS IS IN PART
DUE TO THE SNOW LEVELS INCREASING AS THE FLOW TURNS TO THE SOUTHWEST
BRINGING IN WARMER AIR ALOFT. NBM SHOWS SNOW LEVELS INCREASING TO
ABOVE 5500 FEET BY THURSDAY. 90
PRELIMINARY POINT TEMPS/POPS
PDT 34 20 38 24 / 0 0 0 0
ALW 34 23 37 27 / 0 0 0 0
PSC 37 22 37 23 / 0 0 0 0
YKM 34 22 35 23 / 0 0 0 0
HRI 35 22 36 23 / 0 0 0 0
ELN 30 20 33 23 / 0 0 0 0
RDM 41 22 48 24 / 0 0 0 0
LGD 38 23 40 26 / 0 0 0 0
GCD 44 24 46 26 / 0 0 0 0
DLS 36 25 41 28 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
SHORT TERM...90
LONG TERM....90
AVIATION...95
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