747
FXUS66 KPDT 261109
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
309 AM PST FRI DEC 26 2025
DISCUSSION...
KEY MESSAGES:
1. WIDESPREAD LIGHT PRECIPITATION PERSISTS TODAY.
2. SIGNIFICANT MOUNTAIN SNOWFALL TODAY THROUGH EARLY SATURDAY.
*WINTER ADVISORIES IN EFFECT*
3. DRIER AND COOLER CONDITIONS EARLY IN THE WEEK.
A WEAK UPPER TOUGH/SURFACE COLD FRONTAL SYSTEM IS POSITIONED
ALONG THE PAC NW COAST THIS MORNING. AND POISED TO LIFT INLAND
THROUGH TODAY AND TONIGHT BRINGING PRECIPITATION ACROSS THE
REGION, AND WINDY CONDITIONS OVERNIGHT AND EARLY SATURDAY.
WINTER WEATHER ADVISORIES STILL LOOKS GOOD FOR THE SNOQUALMIE
PASS AREAS OF THE WA CASCADES AS THE PROBABILITY FOR EXCEEDANCE OF
8 AND 12 INCH SNOWFALL THROUGH 15Z SATURDAY IS AT AROUND 90 AND
40 PERCENT RESPECTIVELY, AND FOR 8 OR MORE INCHES AT THE SANTIAM
PASS IN THE OREGON CASCADES, THE PROBABILITY AROUND 63 PERCENT.
LIKEWISE AT TOLLGATE OR, ABOUT 50%, BOTH WELL BELOW AN 80% TRIGGER
FOR WINTER STORM WARNINGS. AS FAR AS WIND GOES, THE BREEZY TO
MARGINALLY WINDY CONDITIONS FOLLOWING THE PRECIPITATION SHOULD
LAST THROUGH THE OVERNIGHT FRIDAY INTO EARLY DAY SATURDAY BUT
FALL BELOW THE WIND ADVISORY CRITERION OF SUSTAINED WINDS UP
AROUND 26 KNOTS OR MORE. WITH HIGH PRESSURE SETTLING IN OVER THE
FOLLOWING DAYS, (SUNDAY AND BEYOND) INVERSIONS DIURNALLY WILL BE
A RISK TO TRAVELERS AT TIMES. ONE AREA PRONE IS THE I-84 AND OTHER
HIGHWAYS OF THE BLUE MOUNTAIN FOOTHILLS AND LOWER COLUMBIA BASIN,
AS WELL AS OTHER VALLEYS OF SOUTH CENTRAL WASHINGTON WHERE THE
PROBABILITY FOR FOG SHOWS UP AT AROUND 20-40% THESE PROBABILITIES
HAVE TRIGGERED THE MENTION OF SOME PATCHY AND AREAS OF FOG EARLY
TO MID WEEK, IN WHAT OTHERWISE LOOKS TO BE A RELATIVELY UNEVENTFUL
WEATHER PERIOD.
AVIATION...12Z TAFS...TAFS RANGE FROM VFR TO LIFR AT THIS TIME DUE
TO STRATUS AND FOG. PRECIPITATION HAS MOVED IN AND HAS LOWERED
RDM/BDN TO LIFR. HOWEVER, CONFIDENCE THAT WILL CLEAR IN THE NEXT FEW
HOURS IS MODERATE (40-60%). MOST, IF NOT ALL SITES WILL SEE AT LEAST
MVFR CONDITIONS, AND SOME MANY COULD GET LOWER, THOUGH CONFIDENCE IS
FLIGHT CATEGORIES (AND TIMING) IS BELOW AVERAGE AT BEST. BY FRIDAY
AFTERNOON, ALL SITES SHOULD BE BACK TO VFR.
WINDS WILL BE LESS THAN 10 KTS THROUGH MUCH OF THE PERIOD, BUT WILL
INCREASE AND BECOME GUSTY DURING THE AFTERNOON AND EVENING HOURS AT
PDT, ALW, YKM AND PSC AND COULD GUST IN THE 20 TO 25 KT RANGE. 90
PRELIMINARY POINT TEMPS/POPS
PDT 48 30 40 23 / 80 70 50 0
ALW 47 31 38 25 / 90 90 60 0
PSC 47 30 42 21 / 80 50 10 0
YKM 44 24 40 20 / 40 30 0 0
HRI 48 31 43 23 / 80 60 20 0
ELN 38 23 34 18 / 50 40 0 0
RDM 44 24 38 18 / 40 30 10 0
LGD 44 28 33 20 / 70 90 80 0
GCD 43 28 34 20 / 70 80 70 0
DLS 46 34 44 30 / 80 70 20 0
PDT WATCHES/WARNINGS/ADVISORIES
OR...WINTER WEATHER ADVISORY UNTIL 7 AM PST SATURDAY FOR ORZ502-509.
WA...WINTER WEATHER ADVISORY UNTIL 7 AM PST SATURDAY FOR WAZ030-522.
FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR WAZ026.
FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR WAZ027.
DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR WAZ029.
DISCUSSION...71
AVIATION...90
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page