307
FXUS66 KPDT 172250
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
350 PM PDT SAT OCT 17 2026
KEY MESSAGES
- BREEZY TO LOCALLY WINDY THROUGH THE CASCADE GAPS AND ACROSS
MUCH OF THE COLUMBIA PLATEAU THIS AFTERNOON AND EVENING.
- COOLER, NEAR-NORMAL TEMPERATURES SUNDAY INTO NEXT WEEK IN THE
WAKE OF TODAY'S COLD FRONTAL PASSAGE.
- MOSTLY DRY CONDITIONS CONTINUE INTO NEXT WEEK. LOW (20-40%)
CHANCE OF PRECIPITATION ACROSS THE BLUE MOUNTAINS BY LATE
WEDNESDAY, EXPANDING TO COVER THE CASCADE AND BLUE MOUNTAINS
THURSDAY THROUGH THE REMAINDER OF THE WEEK.
DISCUSSION
SATELLITE SHOWS A WEAK COLD FRONT PASSING FROM WEST TO EAST
ACROSS THE FORECAST AREA THIS AFTERNOON. BREEZY TO LOCALLY WINDY
WESTERLY WINDS WILL PERSIST THROUGH THE CASCADE GAPS AND ACROSS
MUCH OF THE COLUMBIA PLATEAU THROUGH EVENING (95% CONFIDENCE),
WITH LIGHTER WINDS RETURNING THIS EVENING AND TONIGHT IN THE
WAKE OF THE FRONT.
COOL OVERNIGHT LOWS RANGING FROM THE LOWER 30S TO LOWER 40S ARE
FORECAST TONIGHT, LOCALLY NEAR OR SLIGHTLY BELOW FREEZING FOR
COLD-PRONE LOCATIONS OF THE COLUMBIA BASIN AND SURROUNDING
LOWLANDS, BUT CONFIDENCE IN WIDESPREAD FREEZING TEMPERATURES WAS
TOO LOW (40% OR LESS) TO ISSUE ANY FREEZE HEADLINES.
DRY ZONAL TO QUASI-ZONAL FLOW ALOFT IS FORECAST OVER THE PACIFIC
NORTHWEST ON SUNDAY. UPWIND IN THE PACIFIC, ENSEMBLE NWP
GUIDANCE IS IN EXCELLENT AGREEMENT (99% CONFIDENCE) THAT A
CLOSED LOW WILL DEVELOP OFFSHORE AND TRACK TOWARDS THE PACIFIC
NORTHWEST. WHILE SOME DIFFERENCES IN THE EXACT TRACK AND DEPTH
OF THE LOW ARE PRESENT AMONG CLUSTERS OF ENSEMBLE SOLUTIONS,
THEY ALL INDICATE IT WILL DIVE SOUTHEAST TOWARDS THE OR/CA
BORDER BY MONDAY, WITH VERY LOW (10% OR LOWER) CHANCES OF
PRECIPITATION ACROSS THE CENTRAL OREGON REGION.
THE LOW WILL LIKELY CONTINUE TO TRACK SOUTH OFF THE CALIFORNIA
COAST TUESDAY THROUGH WEDNESDAY (90% CONFIDENCE). WEAK SHORTWAVE
ENERGY MAY FACILITATE PRECIPITATION ACROSS THE BLUE MOUNTAINS
REGION BY WEDNESDAY NIGHT (20-40% POPS), BUT THE MAIN LOW IS
EXPECTED (90% CONFIDENCE) TO REMAIN WELL SOUTH OF OUR REGION.
LOW-MEDIUM (20-60%) POPS THEN CONTINUE THURSDAY THROUGH THE
REMAINDER OF THE WEEK AS THE UPPER LOW TRACKS INLAND ACROSS
CALIFORNIA AND THE GREAT BASIN, AND SHORTWAVE ENERGY FROM THE
PACIFIC MAY TRACK INTO THE REGION (50-80% CONFIDENCE).
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
VFR CONDITIONS TO PERSIST FOR ALL SITES EXCEPT KBDN AND KRDM
HAVING LOW CLOUD BASES BELOW 3000 RESULTING IN MVFR CONDITIONS
FORM 6Z TO 17Z. ALL SITES HAVE INCREASING CLOUD COVER TOWARDS
THE EVENING INTO THE OVERNIGHT WITH LOWERING CLOUD BASES. KDLS
HAS GUSTS OF 25KT AND WILL LAST THROUGH 2Z. CALMER CONDITIONS
AND HIGHER CLOUD BASES APPEAR TOWARDS THE END OF THE TAF PERIOD.
PRELIMINARY POINT TEMPS/POPS
PDT 35 63 36 62 / 0 0 0 0
ALW 40 64 42 62 / 0 0 0 0
PSC 36 66 37 64 / 0 0 0 0
YKM 36 64 39 64 / 0 0 0 0
HRI 38 65 37 64 / 0 0 0 0
ELN 31 61 35 61 / 0 0 0 0
RDM 30 63 29 59 / 0 0 0 0
LGD 36 68 40 68 / 0 0 0 0
GCD 36 72 39 70 / 0 0 0 0
DLS 40 68 44 66 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...86
AVIATION...07/95
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