285  
FXUS66 KPDT 180535  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
1035 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 /06Z TAFS THROUGH 06Z MONDAY/
 
 
VFR CONDITIONS PREVAIL. WINDS ARE RELATIVELY LIGHT THROUGHOUT  
THE PERIOD. KBDN/KRDM: CEILINGS DO LOWER BUT MAINTAIN ABOVE THE  
THRESHOLD FOR A CHANGE IN FLIGHT CATEGORY.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
PDT 35 64 36 62 / 0 0 0 0  
ALW 40 65 42 62 / 0 0 0 0  
PSC 36 66 36 64 / 0 0 0 0  
YKM 36 64 39 63 / 0 0 0 0  
HRI 38 65 37 63 / 0 0 0 0  
ELN 31 61 35 60 / 0 0 0 0  
RDM 30 63 29 59 / 0 0 0 0  
LGD 36 68 39 68 / 0 0 0 0  
GCD 36 72 38 70 / 0 0 0 0  
DLS 40 68 43 66 / 0 0 0 0  
 

 
   
PDT WATCHES/WARNINGS/ADVISORIES
 
 
WA...NONE.  
OR...NONE.  
 

 
 

 
 
DISCUSSION...86  
AVIATION...18/75  
 
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