876  
FXUS66 KPDT 271736  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
1036 AM PDT MON APR 27 2026  
   
KEY MESSAGES
 
 
- CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON  
IN THE EASTERN MOUNTAINS  
 
- TEMPERATURES GRADUALLY WARMING TO ABOVE NORMAL THROUGH THE  
REMAINDER OF THE WEEK  
 

 
   
DISCUSSION
 
 
TODAY AND TUESDAY: SATELLITE IMAGERY TONIGHT  
SHOWS SCATTERED DECKS OF MID TO HIGH LEVEL CLOUD COVER ACROSS  
PORTIONS OF SOUTHEAST WA AND NORTHEAST OR, WITH VERY LITTLE  
SHOWER ACTIVITY NOTED ON REGIONAL RADAR.  
 
TODAY, A WEAK SHORTWAVE UNDER A NORTH NORTHWEST FLOW ALOFT WILL  
DIVE ACROSS THE INLAND PACNW, RESULTING IN ISOLATED TO SCATTERED  
SHOWER CHANCES ACROSS THE EASTERN MOUNTAINS THIS AFTERNOON.  
A WEAK THUNDERSTORM OR TWO MAY DEVELOP THIS AFTERNOON OVER THE  
EASTERN MOUNTAINS AS DEVELOPING SHOWERS TAP INTO A WEAK POOL OF  
INSTABILITY DEVELOPING INTO THE AFTERNOON (CAPE <500 J/KG AND  
HIGH LOW LEVEL LAPSE RATES). TUESDAY, ANOTHER SHORTWAVE WILL  
MOVE ACROSS THE REGION, BUT WILL TRACK ACROSS EASTERN WA INTO  
FAR NORTHEAST OR DUE TO UPPER RIDGING PUSHING TOWARDS THE PACNW.  
SHOWER ACTIVITY WILL BE LIMITED THE NORTHERN BLUES AND RIDGES  
IN WALLOWA COUNTY IN THE AFTERNOON.  
 
WEDNESDAY THROUGH FRIDAY: UPPER LEVEL RIDGING WILL BUILD OVER  
THE REGION THROUGH THE LATTER HALF OF THE WORK WEEK (CONFIDENCE  
70-85%). THIS WILL RESULT IN DRYING AND WARMING CONDITIONS  
ACROSS MUCH OF THE FORECAST AREA. HIGH TEMPERATURES WILL WARM  
WELL ABOVE NORMAL, WITH MID 70S IN THE MID ELEVATIONS (CENTRAL  
OR) AND UPPER 70S TO LOWER 80S IN THE LOWER ELEVATIONS.  
 
SATURDAY AND SUNDAY: ENSEMBLE CLUSTER GUIDANCE IS IN GOOD  
AGREEMENT THAT A POSITIVELY TILTED UPPER TROUGH WILL SLIDE OVER  
THE PACNW THROUGH THE WEEKEND, HOWEVER THERE IS DISAGREEMENT ON  
THE DEPTH AND POSITION OF THE TROUGH AS IT MOVES INLAND.  
REGARDLESS OF THE POSITION, ENSEMBLE CLUSTER SOLUTIONS INDICATE  
A SOUTHWEST FLOW INTO THE INLAND PACNW, KEEPING TEMPERATURES  
ABOVE NORMAL OVER THE WEEKEND. THE UPPER TROUGH AND SOUTHWEST  
FLOW ALOFT WILL ALSO PROMOTE SHOWER CHANCES OVER THE EASTERN  
MOUNTAINS BOTH SATURDAY AND SUNDAY AFTERNOONS, WITH A SLIGHT  
CHANCE OF ISOLATED THUNDERSTORMS DEVELOPING AS WELL (CONFIDENCE  
30-50%). LAWHORN/82  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
 
 
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. WINDS WILL  
GENERALLY BE 10 KTS OR LESS, EXCEPT AT BDN, RDM AND DLS WHERE  
WINDS WILL GUST IN THE 20 TO 25 KT RANGE THIS AFTERNOON AND INTO  
THE EARLY EVENING BEFORE SUBSIDING BACK TO 10 KTS OR LESS THIS  
EVENING.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
PDT 65 41 66 40 / 20 10 0 0  
ALW 66 45 67 44 / 20 10 0 0  
PSC 71 43 72 43 / 20 0 0 0  
YKM 69 40 70 41 / 10 10 0 0  
HRI 69 43 69 41 / 20 0 0 0  
ELN 64 40 62 38 / 10 10 0 0  
RDM 62 29 64 30 / 0 0 0 0  
LGD 59 35 64 40 / 40 10 10 0  
GCD 58 32 64 38 / 40 10 10 0  
DLS 69 44 66 42 / 0 0 0 0  
 

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

 
 

 
 
DISCUSSION...82  
AVIATION...77  
 
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