824  
FXUS66 KPDT 271110  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
410 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 /12Z TAFS THROUGH 12Z TUESDAY/  
VFR CONDITIONS TO  
PREVAIL THROUGH THE PERIOD. ONLY EXCEPTION WILL BE AT SITE BDN  
WHERE VSBY MAY LOWER TO AROUND 3SM THIS MORNING DUE TO SMOKE  
FROM A NEARBY FIRE. SHOWERS WILL DEVELOP ALONG THE BLUE  
MOUNTAINS THIS AFTERNOON, THOUGH CHANCES OF SHOWERS AT SITES  
PDT/ALW (<20%) WERE TOO LOW TO INCLUDE AT THIS TIME. WINDS WILL  
GENERALLY BE LIGHT, 12KTS OR LESS, THROUGH THE PERIOD. EXCEPT AT  
SITE DLS WHERE WINDS WILL INCREASE TO AROUND 15KTS WITH GUSTS UP  
TO 25KTS THIS AFTERNOON AND EARLY EVENING. AN OCCASIONAL GUST  
UP TO 20KTS MAY ALSO IMPACT SITES RDM/BDN THIS AFTERNOON.  
LAWHORN/82  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
PDT 65 41 67 40 / 10 0 0 0  
ALW 65 45 67 44 / 30 10 10 0  
PSC 71 43 72 42 / 0 0 0 0  
YKM 69 41 71 41 / 0 0 0 0  
HRI 69 43 69 41 / 0 0 0 0  
ELN 63 40 62 39 / 10 0 0 0  
RDM 61 30 65 31 / 0 0 0 0  
LGD 58 35 64 39 / 50 10 10 0  
GCD 58 33 64 37 / 40 10 10 0  
DLS 68 44 67 42 / 10 0 0 0  
 
 
   
PDT WATCHES/WARNINGS/ADVISORIES  
 
WA...NONE.  
OR...NONE.  
 
 
 
 
 
DISCUSSION...82  
AVIATION...82  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab OR Page
The Nexlab WA Page
Main Text Page