574
FXUS66 KPDT 141139
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
439 AM PDT TUE APR 14 2026
KEY MESSAGES
- MOUNTAIN SNOW RETURNS TODAY THROUGH THURSDAY
- NEAR TO SUB-FREEZING TEMPERATURES IN THE LOWER ELEVATIONS
THURSDAY AND FRIDAY MORNINGS
- DRIER CONDITIONS RETURN FRIDAY INTO SATURDAY, BUT PRECIP
CHANCES WILL DEVELOP AGAIN BY SUNDAY
DISCUSSION
TODAY THROUGH THURSDAY: A STRONG UPPER LOW WITH A
LEADING COLD FRONT DROPPING OUT OF THE GULF OF ALASKA WILL MOVE
ACROSS THE PACNW STARTING TODAY, BRINGING WITH IT WIDESPREAD
RAIN AND MOUNTAIN SNOW CHANCES (CONFIDENCE 80-85%). THE BEST
PRECIPITATION CHANCES IN THE LOWER ELEVATIONS WILL BE ASSOCIATED
WITH THE COLD FRONT PASSAGE LATE TONIGHT THROUGH WEDNESDAY
AFTERNOON, WITH CHANCES TAPERING OFF LATE WEDNESDAY THROUGH
THURSDAY. THE UPPER LOW AND COLD FRONT WILL BRING A MUCH COLDER
AIRMASS TO THE REGION, RESULTING IN SNOW LEVELS STEADILY
DROPPING TO BELOW PASS LEVELS BY TONIGHT, AND BETWEEN 1.5KFT TO
2KFT BY WEDNESDAY EVENING. WHILE THE BULK OF PRECIP WILL FALL
BEFORE WEDNESDAY EVENING IN THE LOWER ELEVATIONS, PORTIONS OF
CENTRAL AND NORTH CENTRAL OR WILL SEE LIGHT RAIN TRANSITION TO
LIGHT SNOW. OTHERWISE, MODERATE TO LOCALLY HEAVY SNOW SHOWERS
WILL DEVELOP ACROSS THE CASCADE CREST AND THE NORTHERN BLUES
THIS EVENING THROUGH WEDNESDAY EVENING, WITH SNOW TAPERING OFF
THROUGH WEDNESDAY NIGHT AND THURSDAY. MULTIPLE WINTER WEATHER
HEADLINES ARE IN EFFECT TODAY THROUGH WEDNESDAY NIGHT IN
ANTICIPATION OF IMPACTS FROM THE HEAVY MOUNTAIN SNOW. THERE
REMAINS HIGH CONFIDENCE (80-85%) IN SNOW ACCUMULATIONS BETWEEN
6-12 INCHES FOR THE OR CASCADE EAST SLOPES ABOVE 4000 FEET, 4-8
INCHES FOR THE UPPER EAST SLOPES OF THE WA CASCADE EAST SLOPES,
AND 5-10 INCHES FOR THE NORTHERN BLUES ABOVE 4500 FEET. THE
HEAVIEST SNOW ACCUMULATIONS ARE EXPECTED LATER TONIGHT AS THE
COLD FRONT SLIDES THROUGH THE REGION, WITH UPSLOPE SNOW SHOWERS
PERSISTING THROUGH THE REMAINDER OF WEDNESDAY.
BREEZY WINDS WILL CONTINUE TO IMPACT THE REGION THROUGH THE
MIDWEEK AS THE COLD FRONT PASSAGE AND CONTINUED COLD AIR
ADVECTION INTO THE FORECAST AREA RESULT IN TIGHTENED PRESSURE
GRADIENTS. CONFIDENCE IS MODERATE-HIGH (55-85%) THAT WESTERLY
WINDS WILL REMAIN BETWEEN 15-30MPH AND GUSTS 25-45MPH THROUGH
THE MIDWEEK. THAT SAID, WIND-PRONE AREAS IN THE COLUMBIA BASIN
AND BLUE MOUNTAIN FOOTHILLS WILL SEE A 65-85% CHANCE OF GUSTS
EXCEEDING 45 MPH EACH DAY THROUGH THURSDAY. OTHERWISE, CLEARING
SKIES, DRY SURFACE CONDITIONS, AND COLD AIR ADVECTION INTO THE
REGION WILL RESULT IN NEAR TO BELOW FREEZING MORNING
TEMPERATURES THURSDAY AND FRIDAY. OF PARTICULAR CONCERN ARE THE
KITTITAS AND YAKIMA VALLEYS, WHERE THERE IS 65-85% CHANCE OF
MORNING LOWS BELOW FREEZING THURSDAY AND FRIDAY.
FRIDAY THROUGH MONDAY: ENSEMBLE GUIDANCE IS IN GOOD AGREEMENT
OF UPPER LEVEL RIDGING SLIDING ACROSS THE PACNW WITH DRY
CONDITIONS AND LIGHT WINDS BY FRIDAY (CONFIDENCE 60-75%). THE
FORECAST AREA WILL REMAIN UNDER THE INFLUENCE OF THE RIDGE
THROUGH SATURDAY AFTERNOON, BUT ENSEMBLE MEMBERS DISAGREE ON
THE EVOLUTION OF THE SYNOPTIC PATTERN LATE SATURDAY INTO MONDAY.
THAT SAID, THERE IS GOOD AGREEMENT IN SOME FORM OF UPPER LOW
BRINGING ANOTHER ROUND OF PRECIPITATION CHANCES TO THE REGION
SUNDAY INTO EARLY NEXT WEEK. LAWHORN/82
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
VFR CONDITIONS TO
PREVAIL THROUGH THE PERIOD. AN UPPER LEVEL SYSTEM WILL BRING
RAIN IMPACTS TO SITES BEGINNING LATE THIS AFTERNOON, WITH SHOWER
CHANCES DEVELOPING AT SITES PDT/ALW/PSC BETWEEN 23Z AND 6Z.
LIGHT RAIN WILL DEVELOP AT SITE DLS AFTER 6Z AND PERSIST INTO
THE END OF THE PERIOD. WINDS WILL INCREASE TO 12-20KTS WITH
GUSTS 20-30KTS AT ALL SITES TODAY, WITH WINDS BECOMING LIGHT AT
SITES DLS/RDM/YKM AROUND 2-3Z. OTHERWISE, WINDS WILL REMAIN
ELEVATED AT ALL OTHER SITES THROUGH THE PERIOD. LAWHORN/82
PRELIMINARY POINT TEMPS/POPS
PDT 58 41 52 31 / 10 60 90 40
ALW 58 42 52 34 / 20 80 100 60
PSC 61 44 58 34 / 20 40 70 20
YKM 58 39 55 30 / 20 60 30 10
HRI 60 42 57 33 / 10 40 80 20
ELN 51 32 48 29 / 40 70 30 10
RDM 56 35 49 23 / 10 50 90 30
LGD 56 39 49 29 / 10 90 100 70
GCD 58 38 48 26 / 10 70 100 70
DLS 58 41 54 35 / 40 80 70 20
PDT WATCHES/WARNINGS/ADVISORIES
WA...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM PDT
WEDNESDAY FOR WAZ030.
WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 11 PM PDT
WEDNESDAY FOR WAZ522.
OR...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM PDT
WEDNESDAY FOR ORZ502.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM PDT
THURSDAY FOR ORZ509.
DISCUSSION...82
AVIATION...82
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