780
FXUS66 KPDT 151147
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
447 AM PDT WED APR 15 2026
KEY MESSAGES
- MOUNTAIN SNOW WILL PERSIST THROUGH THURSDAY MORNING
- BREEZY CONDITIONS IN THE LOWER ELEVATIONS THROUGH THURSDAY
- NEAR TO BELOW FREEZING MORNING LOWS THURSDAY AND FRIDAY FOR
THE LOWER ELEVATIONS
DISCUSSION
TODAY THROUGH THURSDAY: SATELLITE AND REGIONAL
RADAR IMAGERY SHOW A COLD FRONT SLOWLY PUSHING SOUTHEAST ACROSS
THE PACNW THIS EARLY MORNING, WITH SNOW SHOWERS ALONG THE
CASCADE CREST AND ACROSS THE BLUE MOUNTAINS.
THE COLD FRONT HAS MOSTLY STALLED ALONG THE CASCADE CREST THIS
MORNING, WHICH HAS RESULTED IN MODERATE SNOW SHOWERS IMPACTING
THE CASCADE PASSES. THE COLD FRONT IS EXPECTED TO PASS OVER THE
CASCADE CREST LATER THIS MORNING AND CONTINUE TO PUSH SOUTHEAST
ACROSS THE FORECAST AREA THROUGH THIS EVENING, WHILE A CLOSED
LOW IS EXPECTED TO ARRIVE TO THE REGION BY THIS AFTERNOON. THE
BEST CHANCES FOR PRECIPITATION IN THE LOWER ELEVATIONS WILL BE
ASSOCIATED WITH THE FRONTAL PASSAGE TODAY, WITH MANY LOCATIONS
ONLY SEEING RAIN THROUGHOUT THE DAY. HOWEVER, SNOW LEVELS
PLUMMETING TO AROUND 2KFT BEHIND THE FRONTAL BOUNDARY AND
ANTICIPATED POST-FRONTAL SHOWERS WILL BRING CHANCES (30-40%) OF
LIGHT SNOW TO PORTIONS OF CENTRAL OR THIS EVENING. BY TONIGHT,
THE UPPER LOW WILL MOVE OVER THE FORECAST AREA, CUTTING OFF
PRECIP CHANCES IN THE LOWER ELEVATIONS.
AS FOR THE MOUNTAINS, MODERATE TO LOCALLY HEAVY SNOW SHOWERS
WILL CONTINUE TO DEVELOP ACROSS THE CASCADE CREST AND THE
NORTHERN BLUES THROUGH THIS EVENING, WITH SNOW TAPERING OFF
LATE TONIGHT INTO THURSDAY MORNING. MULTIPLE WINTER WEATHER
HEADLINES ARE IN EFFECT TODAY THROUGH TONIGHT AND EARLY THURSDAY
MORNING IN ANTICIPATION OF IMPACTS FROM THE HEAVY MOUNTAIN
SNOW. THERE REMAINS HIGH CONFIDENCE (85-90%) IN SNOW
ACCUMULATIONS TOTALING 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 TO OCCUR WITH THE COLD FRONT PASSAGE THIS MORNING,
BECOMING LIGHT TO LOCALLY MODERATE THROUGH THE REMAINDER OF
TODAY.
BREEZY WINDS WILL CONTINUE TO IMPACT THE REGION THROUGH THURSDAY
AS THE COLD FRONT PASSAGE AND CONTINUED COLD AIR ADVECTION INTO
THE FORECAST AREA RESULT IN TIGHTENED PRESSURE GRADIENTS.
CONFIDENCE IS MODERATE-HIGH (60-85%) THAT WESTERLY WINDS WILL
REMAIN BETWEEN 15-30MPH AND GUSTS 25-45MPH. THAT SAID, WIND-PRONE
AREAS IN THE COLUMBIA BASIN AND BLUE MOUNTAIN FOOTHILLS WILL
SEE A 65-85% CHANCE OF GUSTS EXCEEDING 45 MPH TODAY AS THE COLD
FRONT BOUNDARY MOVES THROUGH THE REGION. 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 80-90% CHANCE OF
MORNING LOWS BELOW FREEZING BOTH DAYS; THE NORTHERN BLUE
MOUNTAIN FOOTHILLS OF OR ARE ALSO A CONCERN WHERE THERE IS A
60-80% CHANCE OF BELOW FREEZING LOWS, ESPECIALLY IN AREAS PRONE
TO COLD-POOLING. FREEZE WARNINGS HAVE BEEN ISSUED IN THESE AREAS
FOR THURSDAY MORNING, AND WILL LIKELY NEED TO BE REISSUED FOR
FRIDAY MORNING.
FRIDAY THROUGH TUESDAY: ENSEMBLE GUIDANCE IS IN GOOD AGREEMENT
OF UPPER LEVEL RIDGING SLIDING ACROSS THE PACNW WITH DRY
CONDITIONS AND LIGHT WINDS BY FRIDAY (CONFIDENCE 75-90%). THE
FORECAST AREA WILL REMAIN UNDER THE INFLUENCE OF THE RIDGE
THROUGH SATURDAY, BUT ENSEMBLE MEMBERS DISAGREE ON THE
EVOLUTION OF THE SYNOPTIC PATTERN SUNDAY INTO EARLY NEXT WEEK.
THAT SAID, THERE IS GOOD AGREEMENT IN SOME FORM OF UPPER LOW
BRINGING ANOTHER ROUND OF PRECIPITATION CHANCES ACROSS THE
PACNW, BUT CONFIDENCE IS LOW (15-25%) IN TIMING, INTENSITY, AND
P-TYPE. LAWHORN/82
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
VFR CONDITIONS TO
PREVAIL THROUGH THE PERIOD. A COLD FRONT MOVING THROUGH THE
REGION WILL BRING RAIN SHOWER IMPACTS TO ALL SITES THIS MORNING,
WITH ASSOCIATED SHOWERS DIMINISHING AROUND 18Z. POST FRONTAL
RAIN SHOWERS MAY IMPACT SITES DLS/PSC BETWEEN 22-03Z, WHILE
SHOWERS MAY START OFF AS A MIX AND TRANSITION TO SNOW AT SITES
RDM/BDN BETWEEN 01-04Z. WINDS WILL INCREASE TO 12-20KTS WITH
GUSTS 20-35KTS AT ALL SITES THIS MORNING, WITH THESE WINDS
PREVAILING AT SITES PDT/ALW LATE INTO THE EVENING. WINDS WILL
SHIFT TO THE WEST/NORTHWEST BEHIND THE FRONTAL PASSAGE THIS
MORNING AND EARLY AFTERNOON. WINDS WILL BECOME LIGHT, 12KTS OR
LESS, AT SITES DLS/RDM/BDN/YKM/PSC AROUND OR AFTER 03Z.
LAWHORN/82
PRELIMINARY POINT TEMPS/POPS
PDT 51 31 54 33 / 90 40 10 0
ALW 51 34 54 35 / 100 60 30 0
PSC 58 34 61 34 / 70 20 0 0
YKM 55 30 59 30 / 30 10 0 0
HRI 56 33 59 34 / 70 20 0 0
ELN 47 29 51 30 / 20 10 0 0
RDM 49 22 49 22 / 90 30 0 0
LGD 49 29 46 30 / 90 60 50 10
GCD 50 26 45 25 / 100 70 50 10
DLS 53 35 57 36 / 80 20 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...WINTER WEATHER ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
WAZ030-522.
FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM PDT THURSDAY
FOR WAZ026-027.
OR...WINTER WEATHER ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
ORZ502.
FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM PDT THURSDAY
FOR ORZ507.
WINTER STORM WARNING UNTIL 5 AM PDT THURSDAY FOR ORZ509.
DISCUSSION...82
AVIATION...82
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