950
FXUS66 KPDT 201737
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1037 AM PDT TUE OCT 20 2026
KEY MESSAGES
- WARM AND DRY CONDITIONS THROUGH WEDNESDAY.
- BREEZY TO WINDY WESTERLY WINDS THROUGH THE EASTERN COLUMBIA
RIVER GORGE/CASCADE GAPS THURSDAY NIGHT.
- SLIGHT CHANCES (15-25%) FOR THUNDERSTORMS ACROSS THE WALLOWAS
AND BLUE MOUNTAINS OF OREGON, WETTING RAINS, AND BREEZY
WINDS.
DISCUSSION
A BAND OF THICK CLOUDS WERE SPREADING NORTH OUT OF SOUTHERN
OREGON INTO CENTRAL OREGON THIS MORNING, WITH THINNER CLOUDS
ACROSS THE FOOTHILLS AND COLUMBIA BASIN REGION AND RADAR
RETURNS FROM MRMS HAD FADED. WARMER LOW ELEVATIONS ARE EXPECTED
TODAY FOLLOWED BY WARMER FOOTHILLS AND MOUNTAIN AREAS WEDNESDAY
AFTERNOON AS AN UPPER RIDGE PROVIDES SUBSIDENCE. MODELS SHOW AN
UPPER LOW OVER THE EASTERN PACIFIC COMING ONSHORE OVER CA EARLY
THURSDAY, AND ASSOCIATED TROUGH/COLD FRONTAL BOUNDARY TO THE
NORTH OVER THE PAC NW/INTERIOR NW LATE THURSDAY THROUGH EARLY
FRIDAY. ASSOCIATED WITH THE SOUTHERLY FLOW AHEAD OF THE COLD
FRONT, SBCAPES THROUGH THE EASTERN MOUNTAINS AVERAGE ABOUT 200-300
J/KG THURSDAY AFTERNOON, WITH NBM PRINTING UP TO AROUND 20%
PROBABILITY FOR THUNDER ACROSS THE BLUE MOUNTAINS OF OREGON AND
WALLOWA COUNTY. HOWEVER, THERE IS CONSIDERABLE UNCERTAINTY IN
THUNDERSTORM POTENTIAL AS THE RANGE BETWEEN THE 25TH AND 75TH
PERCENTILE IS ABOUT 90 TO 470 J/KG. IMPACTS OF THE COLD FRONT
INCLUDE POTENTIAL FOR BREEZY TO STRONG, GUSTY WINDS ACROSS THE
EASTERN COLUMBIA RIVER GORGE AND THE RIDGES AND GAPS ACROSS THE
CASCADES. NBM IS SHOWING ABOUT 50 TO 70 PERCENT CONFIDENCE IN
WIND GUSTS IN EXCESS OF 50 MPH THURSDAY NIGHT, IN THESE
LOCATIONS, FOLLOWING THE PASSAGE OF THE FRONT. THE RISK WINDOW
IS FROM ABOUT MID-EVENING THROUGH FRIDAY MORNING. FINALLY,
CHANCES FOR WETTING RAINS ARE HIGH, IN THE 60 TO 90 PERCENT BY
LATE THURSDAY MORNING AND THROUGH THURSDAY NIGHT/FRIDAY MORNING
ACROSS THE BLUE MOUNTAINS AND WALLOW COUNTY. CHANCES TAPER FROM
WEST TO EAST ON FRIDAY.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
VFR CONDITIONS WITH PREDOMINANTLY LIGHT, DIURNALLY AND TERRAIN-
DRIVEN WINDS ARE FORECAST THROUGH THE PERIOD FOR ALL SITES (95%
CONFIDENCE OR HIGHER).
PRELIMINARY POINT TEMPS/POPS
PDT 63 32 68 38 / 0 0 0 0
ALW 63 39 68 44 / 0 0 0 0
PSC 68 37 69 37 / 0 0 0 0
YKM 70 39 70 40 / 0 0 0 0
HRI 65 34 68 37 / 0 0 0 0
ELN 66 33 67 38 / 0 0 0 0
RDM 62 28 72 31 / 0 0 0 0
LGD 70 39 74 43 / 0 0 10 10
GCD 72 39 76 43 / 0 0 0 20
DLS 71 40 73 44 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...71
AVIATION...86
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