203  
FXUS66 KPDT 062124  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
224 PM PDT SUN SEP 6 2026  
   
KEY MESSAGES  
 
- SHOWER AND THUNDERSTORM CHANCES THROUGH THIS EVENING, WITH  
DECREASING CHANCES ON MONDAY.  
 
- DRY WEATHER THROUGH MUCH OF THE WEEK WITH SEASONABLE  
TEMPERATURES.  
 
- POTENTIAL FOR ANOTHER UPPER TROUGH AND PRECIPITATION NEXT  
WEEKEND.  
 
 
   
DISCUSSION  
 
THE PERSISTENT UPPER LOW THAT HAS BEEN OVER THE PACIFIC  
NORTHWEST WILL BEGIN TO MOVE EASTWARD TONIGHT AND WILL BE WELL  
EAST OF THE REGION ON MONDAY. HOWEVER, SOME TROUGHING WILL  
REMAIN OVER THE AREA AND WILL KEEP UNSETTLED CONDITIONS, MAINLY  
OVER THE EASTERN OREGON MOUNTAINS ON MONDAY, WITH EVERYWHERE  
ELSE REMAINING DRY.  
 
BY TUESDAY, AND THROUGH MUCH OF THE WEEK, THE AREA WILL BE UNDER  
A SPLIT FLOW REGIME, WITH A MORE WESTERLY FLOW MOVING IN BY  
THURSDAY.  
 
ON FRIDAY, ANOTHER UPPER LOW WILL DROP DOWN FROM THE NORTHWEST,  
AND BRING ANOTHER CHANCES OF SHOWERS, AND POSSIBLY SOME  
THUNDERSTORMS, MAINLY TO THE MOUNTAINS. THIS LOW WILL CROSS  
THE REGION ON SATURDAY AND EXIT ON SUNDAY. UNLIKE THE CURRENT  
LOW, THIS LOOKS TO BE A FAST MOVING PROGRESSIVE LOW.  
 
LATEST RADAR SHOWED ISOLATED TO SCATTERED SHOWERS. SATELLITE  
IMAGERY SHOWED ABUNDANT CLOUD COVER AND MANY AREAS WERE  
STRUGGLING IN THE 50S AND LOWER 60S, THOUGH THE COLUMBIA BASIN  
WAS CLOSE TO 70 DEGREES. CLOUD COVER IS AFFECTING THUNDERSTORM  
DEVELOPMENT, BUT IF WE ARE ABLE TO GET SOME SUFFICIENT BREAKS  
LATER THIS AFTERNOON, THE MOST LIKELY AREAS FOR THUNDERSTORM  
DEVELOPMENT WOULD BE FROM THE NORTHERN BLUE MOUNTAINS EASTWARD.  
 
IN AREAS OF HEAVY RAIN, THE COULD BE 0.25 TO 0.50 INCHES, BUT  
MOST PLACES WILL SEE LESS THAN 0.25 INCHES.  
 
MONDAY WILL SEE BREEZY WINDS, IN THE 25 TO 30 MPH RANGE,  
POSSIBLY AS HIGH AS 35 MPH ACROSS THE CASCADE GAPS, KITTITAS  
VALLEY, SIMCOE HIGHLANDS AND THE COLUMBIA BASIN AND GORGE.  
 
ANOTHER BREEZY PERIOD WILL BE THURSDAY ACROSS THE SAME AREAS IN  
ADVANCE OF THE NEXT TROUGH WINDS WILL BE SIMILAR (POSSIBLY A BIT  
HIGHER), THOUGH RH VALUES WILL BE LOWER ON THURSDAY. AREAL  
COVERAGE OF WIND GUSTS ARE A BIT MORE ON THURSDAY WHILE  
PROBABILITIES OF WIND GUSTS >= 25 MPH >80 PERCENT BOTH DAYS.  
 
HIGH TEMPERATURES WILL REMAIN 10 TO 15 DEGREES BELOW NORMAL ON  
LABOR DAY BEFORE RISING TO NEAR SEASONAL NORMALS FOR MUCH OF THE  
WEEK. HIGHS WILL TEN DROP BELOW NORMAL AGAIN FRIDAY AND SATURDAY  
AS THE NEXT TROUGH MOVES THROUGH. THE ECMWF EFI HAS 0.8 TO 0.9  
BELOW NORMAL FOR MONDAY ACROSS MAINLY CENTRAL AND EASTERN  
PORTIONS OF OREGON.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z MONDAY/  
 
VFR CONDITIONS PREVAIL WITH ON AND OFF SHOWERS CONTINUING  
THROUGH THE REST OF TODAY. MVFR CONDITIONS ARE POSSIBLE THROUGH  
AREAS WHERE A MORE MODERATE TO HEAVY SHOWER PASSES THROUGH THE  
AREA (10 TO 20 PERCENT CHANCE). OTHERWISE, WINDS WILL BE  
GENERALLY LIGHT AND VARIABLE WITH MOST SUSTAINED WINDS AT LESS  
THAN 12 KNOTS.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
PDT 47 71 42 76 / 20 20 0 0  
ALW 51 73 49 78 / 50 30 0 0  
PSC 50 77 48 80 / 10 20 0 0  
YKM 52 77 51 79 / 20 0 0 0  
HRI 50 75 48 79 / 10 20 0 0  
ELN 48 71 45 77 / 20 0 0 0  
RDM 37 68 37 75 / 30 0 0 0  
LGD 45 68 41 74 / 90 40 10 0  
GCD 44 67 41 76 / 70 10 0 0  
DLS 53 75 51 80 / 20 0 0 0  
 
 
   
PDT WATCHES/WARNINGS/ADVISORIES  
 
WA...NONE.  
OR...NONE.  
 
 
 
 
 
DISCUSSION...77  
AVIATION...95  
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