896
FXUS66 KPDT 071130
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
330 AM PST SAT FEB 7 2026
UPDATED AVIATION DISCUSSION
DISCUSSION
STRATUS AND PATCHY FOG CONTINUE TO IMPACT THE
COLUMBIA BASIN AND ADJACENT VALLEYS/FOOTHILLS TONIGHT THANKS TO A
RIDGE OF HIGH PRESSURE PERSISTING OVERHEAD. AREAS OUTSIDE OF THE
COLUMBIA BASIN ARE CURRENTLY UNDER MOSTLY CLEAR SKIES, THOUGH
SATELLITE DOES SHOW CIRRUS BEGINNING TO CROSS THE CASCADE CREST
AT THIS TIME. EXPECT CLEAR SKIES TO BE REPLACED WITH HIGH TO MID
LEVEL CLOUD COVER THROUGH THE REMAINDER OF THE DAY, WHILE THE
LOW STRATUS AND PATCHY FOG IN THE BASIN WILL PERSIST THROUGH THE
MORNING HOURS.
TODAY THROUGH MONDAY: PRECIPITATION CHANCES WILL RETURN TO THE
FORECAST AREA TODAY AS A WEAK PLUME OF MOISTURE ARRIVES TO THE
PACNW WITH A SURFACE FRONTAL SYSTEM. SNOW LEVELS WILL REMAIN
ABOVE 6KFT THROUGH TOMORROW MORNING, RESULTING IN MOSTLY RAIN
FALLING BELOW THE HIGHEST PEAKS IN THE MOUNTAIN AREAS. BY EARLY
SUNDAY MORNING, A STALLED FRONT WILL LAY NORTHEAST TO SOUTHWEST
ACROSS THE FORECAST AREA, RESULTING IN STEADY PRECIPITATION
FALLING OUTSIDE OF THE WA CASCADE EAST SLOPES AND THE
YAKIMA/KITTITAS VALLEYS. SNOW LEVELS WILL BE 4KFT TO 5.5KFT
ACROSS CENTRAL WA, BUT RISING TO 5.5KFT TO 7KFT ACROSS THE
REMAINDER OF THE FORECAST AREA, RESULTING IN MOSTLY RAIN FALLING
THROUGH THE FIRST HALF OF SUNDAY. A SHORTWAVE ARRIVING TO THE
REGION THE LATTER HALF OF SUNDAY WILL PULL THE STALLED FRONTAL
BOUNDARY/DEFORMATION AREA NORTH WHILE DROPPING SNOW LEVELS TO
3KFT TO 4.5KFT SUNDAY NIGHT. THIS WILL RESULT IN THE BEST CHANCE
OF SNOW ACCUMULATIONS ACROSS THE CASCADES AND BLUES, THOUGH THE
NBM IS ONLY SHOWING A 40-65% CHANCE OF 4 INCHES OF SNOW
ACCUMULATIONS IN THESE AREAS THROUGH MONDAY MORNING.
THE INCOMING SHORTWAVE LATE SUNDAY WILL PRODUCE BREEZY WINDS
IN THE LOWER ELEVATIONS AND ALONG EXPOSED RIDGES, WITH WIND
GUSTS BETWEEN 25 TO 35 MPH DEVELOPING SUNDAY NIGHT INTO MONDAY
MORNING.
LIGHT SNOW WILL CONTINUE ACROSS THE CASCADE CREST AND THE
INTERIOR NORTHERN BLUES AS FLOW ALOFT BECOMES ZONAL BRIEFLY
EARLY MONDAY. BY MONDAY EVENING, FLOW ALOFT WILL TRANSITION INTO
A SPLIT FLOW THAT WILL BRING DRY CONDITIONS ACROSS THE REGION.
TUESDAY THROUGH FRIDAY: ENSEMBLE CLUSTER GUIDANCE INDICATES THAT
THE SPLIT FLOW PATTERN WILL PERSIST THROUGH EARLY THURSDAY
BEFORE A TROUGH DROPS SOUTH FROM THE GULF OF ALASKA AND SETS UP
OFFSHORE THE PACNW. ENSEMBLE CLUSTER SOLUTIONS ARE IN GREAT
AGREEMENT THAT CONDITIONS WILL REMAIN DRY UNDER THE SPLIT FLOW
PATTERN. BUT BY LATE THURSDAY INTO FRIDAY, DISAGREEMENT GROWS
WITH STRENGTH AND POSITION OF THE APPROACHING TROUGH. CONFIDENCE
IS AT LEAST MODERATE(45-60%) IN A RETURN OF LIGHT TO MODERATE
SNOW IN THE MOUNTAINS, WITH LOW CONFIDENCE (15-25%) IN HEAVY
SNOW ALONG THE CASCADE EAST SLOPES AND BLUES WITH MORE
WIDESPREAD RAIN/SNOW MIX OR RAIN ACROSS THE REMAINDER OF THE
FORECAST AREA. LAWHORN/82
AVIATION...12Z TAFS
LOW STRATUS AND PATCHY FOG WILL BRING
MVFR OR LOWER CONDITIONS TO MOST SITES THROUGH THIS MORNING,
WITH IMPROVEMENT TO VFR EXPECTED AFTER 18Z. CURRENTLY, THE ONLY
SITE WITH VSBY PROBLEMS IS PDT, WITH VSBY IFR OR LESS EXPECTED
TO PERSIST INTO THE MORNING. A SYSTEM APPROACHING THE REGION
WILL HELP TO LIFT CIGS THROUGH THE AFTERNOON, BUT AS
PRECIPITATION ARRIVES, CIGS ARE EXPECTED TO LOWER TO 3KFT-5KFT
AGL AT MOST SITES. RAIN IMPACTS HAVE BEEN INCLUDED EITHER AS
PREVAILING OR PROB30 GROUPS FOR SITES DLS/PDT/YKM/ALW/PSC THIS
AFTERNOON INTO THE EVENING. MODERATE CONFIDENCE (60-70%) IN MORE
PERSISTENT AND HEAVIER RAINFALL DEVELOPING AFTER 10Z AT SITES
DLS/PDT/ALW/PSC, WITH LOWER CONFIDENCE (20-40%) AT SITES
YKM/RDM/BDN. WINDS WILL BE LIGHT THROUGH THE PERIOD, EXCEPT AT
SITE BDN WHERE SUSTAINED WINDS OF AROUND 12KTS WILL DEVELOP IN
THE AFTERNOON. LAWHORN/82
PRELIMINARY POINT TEMPS/POPS
PDT 43 51 38 50 / 70 90 80 20
ALW 44 50 39 49 / 80 100 90 40
PSC 42 50 38 55 / 70 90 60 10
YKM 38 47 33 50 / 50 70 40 10
HRI 42 50 38 53 / 70 90 60 10
ELN 36 42 31 45 / 60 70 40 10
RDM 40 52 29 47 / 60 90 40 0
LGD 42 50 35 45 / 70 100 100 50
GCD 42 52 34 44 / 50 90 90 20
DLS 44 49 38 52 / 90 90 60 20
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...AIR QUALITY ALERT UNTIL NOON PST TODAY FOR ORZ506-509.
DISCUSSION...82
AVIATION...82
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