048  
FXUS66 KPDT 122207 CCA  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
306 PM PDT WED AUG 12 2026  
   
KEY MESSAGES  
 
- NEAR-SEASONAL TEMPERATURES THROUGH THE WEEK.  
 
- TRANSITION TO A CONVECTIVE WEATHER PATTERN TODAY WITH DAILY  
SHOWER AND THUNDERSTORM CHANCES INTO NEXT WEEK, MAINLY FOR THE  
MOUNTAINS.  
 
- CRITICAL FIRE WEATHER DUE TO LIGHTNING RISK THURSDAY AFTERNOON  
 
 
 
   
DISCUSSION  
 
THE REGION IS TRANSITIONING INTO A CONVECTIVE PATTERN WHICH  
SHOULD LINGER INTO THE EARLY WEEKEND BRINGING POTENTIAL EACH  
AFTERNOON AND EVENING OF SHOWER AND THUNDERSTORMS WITH POSSIBLE  
FIRE WEATHER IMPACTS DUE TO LIGHTNING IF IT IS ABUNDANT ENOUGH.  
CONFIDENCE FOR MEASURABLE PRECIPITATION IS NOT HIGH (IN THE 15  
TO 25% RANGE) THURSDAY AFTERNOON ACROSS THE JOHN DAY  
HIGHLANDS/BASIN AND SOUTHERN BLUE MOUNTAINS HOWEVER THE DROUGHT  
WITH HIGH ERC’S HAVE LEANED US TOWARD THE RED FLAG AS NBM  
MEMBERS AREA TRENDING AROUND 0.1 FLASHES /SQ MILE /5 MINS ACROSS  
THESE ZONES FROM MID AFTERNOON AND ACROSS THE OVERNIGHT HOURS  
INTO FRIDAY MORNING. HRRR SMOKE MODELS SHOW A SOUTHWARD PUSH OF  
VERTICALLY INTEGRATED SMOKE AS SHOWERS AND THUNDERSTORMS CAN  
CREATE OUTFLOW WINDS ACROSS NORTHERN WA AND THE UPPER COLUMBIA  
BASIN OVERNIGHT AND EARLY THURSDAY. TEMPERATURES CONTINUE TO  
REMAIN LARGELY UNCHAINED BY THE PATTERN WITH UPPER 80S AND  
ACROSS THE COLUMBIA BASIN AND COOLER LOW 80S INTO THE FOOTHILLS  
AND MOUNTAIN ZONES, WARMING BACK INTO THE 90S ACROSS THE  
COLUMBIA BASIN BY SUNDAY.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/  
 
VFR CONDITIONS CURRENTLY ACROSS ALL SITES, WHICH WILL STAY THE  
COURSE THROUGH THE PERIOD. ELEVATED SMOKE WILL BE PRESENT AT  
KPDT/KALW/KPSC, BUT VISIBILITIES ARE EXPECTED TO STAY 6SM OR  
ABOVE. BREEZY WINDS AT MOST SITES, WITH SUSTAINED WINDS 10-15KTS  
AND GUSTS OF 15-25KTS. KALW/KPSC WILL EXPERIENCE LIGHTER WINDS  
OF 10KTS OR LESS THROUGH THURSDAY MORNING. 75  
 
 
   
FIRE WEATHER  
 
RED FLAG WARNINGS WERE ISSUED FOR SEVERAL OREGON FIRE ZONES AS  
MONSOONAL MOISTURE INTERACTS WITH WEAK UPPER VORTICITY IN THE  
MEAN TROUGH FROM THE OREGON CASCADES AND EASTWARD THURSDAY  
AFTERNOON/EVENING INTO HE JOHN DAY BASIN AND SOUTHERN BLUE  
MOUNTAINS, EVEN BEYOND MIDNIGHT. THE SEASONAL DRY PERIOD WITH  
HIGH ERC’S HAVE TIPPED US TOWARD THE RED FLAG AS NBM MEMBERS ARE  
TRENDING AROUND 0.1 FLASHES /SQ MILE /5 MINS ACROSS THESE ZONES  
FROM MID AFTERNOON AND ACROSS THE OVERNIGHT HOURS INTO FRIDAY  
MORNING AND ANY GC CAN CREATE NEW STARTS. ANY CONVECTION BEYOND  
THURSDAY WILL BE EVALUATED AGAINST ANY WETTING RAIN CHANCES,  
WHICH WHILE ARE NOT HIGH, ARE QUITE VARIABLE AND AT 10 TO 70% ON  
A 24 HR BASIS HIGHEST IN THE EASTERN OREGON ZONES.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
PDT 52 85 54 87 / 0 0 0 0  
ALW 58 87 59 88 / 0 0 0 0  
PSC 57 89 58 90 / 0 0 0 0  
YKM 58 88 60 88 / 20 0 10 10  
HRI 55 89 57 90 / 0 0 0 0  
ELN 55 83 56 83 / 40 10 20 30  
RDM 44 84 48 85 / 0 0 10 10  
LGD 53 86 55 86 / 0 0 30 30  
GCD 52 87 54 86 / 0 0 50 40  
DLS 60 91 62 91 / 0 0 0 0  
 
 
   
PDT WATCHES/WARNINGS/ADVISORIES  
 
WA...AIR QUALITY ALERT UNTIL 3 PM PDT FRIDAY FOR WAZ026>030-521>523.  
OR...AIR QUALITY ALERT UNTIL 3 PM PDT FRIDAY FOR ORZ041-049-050-502-  
503-505-506-509>511.  
RED FLAG WARNING FROM 1 PM THURSDAY TO 5 AM PDT FRIDAY FOR  
ORZ696>699.  
RED FLAG WARNING FROM 1 PM TO 9 PM PDT THURSDAY FOR ORZ700-705.  
 
 
 
 
 
DISCUSSION...71  
AVIATION...75  
FIRE WEATHER...71  
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