421  
FXUS66 KPDT 102230  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
330 PM PDT MON AUG 10 2026  
 
.UPDATED AVIATION DISCUSSION.  
 
   
KEY MESSAGES
 
 
1. DRY, WARM AND BREEZY CONDITIONS WILL PERSIST THROUGH THE WEEKEND  
AND BEGINNING OF THE WEEK  
 
2. PATTERN SHIFT MID-WEEK COULD BRING PRECIPITATION AND THUNDERSTORM  
CHANCES  
 

 
   
DISCUSSION
 
 
CURRENT SATELLITE SHOWS MOSTLY CLEAR SKIES WITH SMOKE LINGERING IN  
SOME AREAS AROUND THE WILDFIRES. SMOKE WILL CONTINUE TO LINGER  
THROUGH THE PERIOD BUT WITH THE INCREASED WINDS, WILL NOT SETTLE TO  
HEAVILY AT THE SURFACE EXCEPT OVERNIGHT. AQAS ARE STILL IN EFFECT  
FOR MOST COUNTIES EXCEPT SHERMAN, GILLIAM, MORROW AND UMATILLA AND  
WILL REMAIN THROUGH AT LEAST WEDNESDAY BEFORE BEING REEVALUATED.  
 
DRY AND WARM CONDITIONS WILL PERSIST THROUGH MID-WEEK AS WESTERLY  
FLOW ALOFT CONTINUES OVER THE REGION. WESTERLY FLOW WILL CONTINUE  
THROUGH MID WEEK-WITH TEMPERATURES BECOMING SLIGHTLY COOLER. IN  
HOUSE CALCULATIONS SHOWS MUCH OF THE REGION TO STILL BE ABOVE  
SEASONAL AVERAGE NEAR 5 DEGREES ABOVE NORMAL TODAY. AS THE  
TEMPERATURES BEGIN TO DECREASE, RELATIVE HUMIDITY WILL BEGIN TO  
INCREASE. THIS WILL BRING THE AREA OUT OF CRITICAL FIRE WEATHER  
CONDITIONS BUT WILL STILL REMAIN ELEVATED. WINDS ARE EXPECTED TO  
REMAIN 10 TO 15 MPH AND GUSTING BETWEEN 25 TO 35 MPH THROUGH AT  
LEAST TOMORROW WITH 80% OF THE NBM RAW ENSEMBLES IN AGREEMENT.  
 
WEDNESDAY MODELS SHOW AN UPPER LEVEL LOW BEGINNING TO SLIP INTO THE  
PACNW. THIS WILL BRING SOUTHWEST FLOW ALOFT AS WELL AS SOME MID  
LEVEL MOISTURE. LOOKING AT NBM ENSEMBLES, THERE IS A 15-20% CHANCE  
OF THE NORTHERN CASCADES SEEING THUNDERSTORMS. LOOKING AT GFS  
FORECAST SOUNDINGS, THERE IS MUCAPE VALUES OF BETWEEN 250-500 J/KG ,  
LAPSE RATES OF OVER 10 C/KM, LIS OF -2 AND SHEAR OF 24 KTS. THESE  
STORMS WILL LIKELY PROVIDE A STRIKE OR TWO AS WELL AS PRODUCING SOME  
MEASURABLE RAINFALL.  
 
THURSDAY APPEARS TO BE A LULL IN ACTIVITY BEFORE PICKING BACK UP  
FRIDAY. MODELS SHOW THE REGION TO BE WEDGED BETWEEN THE UPPER LEVEL  
TROUGH TO THE NORTH AND THE FOUR CORNER HIGH TO THE SOUTH. THE HIGH  
WILL USHER IN SOME MONSOONAL MOISTURE INTO CENTRAL AND EASTERN OR.  
BY FRIDAY AFTERNOON THE MOISTURE WILL BE OVER CENTRAL OR AND THE  
EASTERN MOUNTAINS WITH NBM ENSEMBLES SHOWING 20-0% CHANCES. AS THIS  
REMAINS FIVE DAYS OUT, WE WILL CONTINUE TO MONITOR AS THE EVENT  
DRAWS NEAR.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
 
 
VFR CONDITIONS CURRENTLY ACROSS ALL SITES, WHICH WILL STAY THE  
COURSE FOR MOST TERMINALS THROUGH THE PERIOD. KRDM/KBDN WILL BE  
THE EXCEPTION AS SMOKE FROM NEARBY WILDFIRES IS EXPECTED TO DROP  
VISIBILITIES THE 5SM LATER THIS EVENING, EXTENDING THROUGH THE  
OVERNIGHT PERIOD. BREEZY WINDS WILL ALSO PERSIST FOR KDLS  
THROUGH TONIGHT, WITH SUSTAINED NORTHWEST WINDS OF 10-20KTS AND  
GUSTS OF 20-30KTS. 75  
 

 
   
FIRE WEATHER
 
 
WESTERLY FLOW HAS BROUGHT COOLER TEMPERATURE AND INCREASING  
RELATIVE HUMIDITY. WHILE THERE ARE BREEZY CONDITIONS EXPECTED  
ACROSS THE REGION, ESPECIALLY THROUGH THE CASCADE GAPS AND ALONG  
THE SOUTHERN BLUE FOOTHILLS, WIND AND RELATIVE HUMIDITY  
THRESHOLDS ARE BELOW CRITICAL. FIRE WEATHER REMAINS ELEVATED AND  
WILL REMAIN ELEVATED THROUGH THE WEEK.  
 
WEDNESDAY COULD SEE CHANCES (15-20%) OF THUNDERSTORMS ALONG THE  
NORTHER CASCADES IN KITTITAS VALLEY. WHILE WE DON'T EXPECT THEM TO  
BE STRONG IN NATURE, WE CAN NOT RULE OUT A STRIKE OR TWO AND GUSTY  
OUTFLOWS. AS WE MOVE INTO FRIDAY, MODELS SHOW MONSOONAL MOISTURE  
MOVING INTO THE SOUTHERN PORTION OF THE REGION THROUGH DESCHUTES,  
CROOK, GRANT AND WALLOWA COUNTIES HAS 20-30% CHANCES OF SEEING  
THUNDERSTORMS. OTHERWISE THE REMAINDER OF THE REGION WILL BE UNDER  
UNSTABLE CONDITIONS.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
PDT 53 88 54 84 / 0 0 0 0  
ALW 60 89 60 86 / 0 0 0 0  
PSC 56 91 57 89 / 0 0 0 0  
YKM 58 92 59 88 / 0 0 0 0  
HRI 57 90 58 87 / 0 0 0 0  
ELN 55 85 55 82 / 0 0 0 0  
RDM 46 88 45 84 / 0 0 0 0  
LGD 52 90 53 87 / 0 0 0 0  
GCD 52 92 52 89 / 0 0 0 0  
DLS 60 88 61 83 / 0 0 0 0  
 

 
   
PDT WATCHES/WARNINGS/ADVISORIES
 
 
WA...AIR QUALITY ALERT UNTIL 11 AM PDT THURSDAY FOR WAZ024-026>030-  
521>523.  
OR...AIR QUALITY ALERT UNTIL NOON PDT WEDNESDAY FOR ORZ041-049-050-  
502-503-505-506-508>511.  
 

 
 

 
 
DISCUSSION...90  
AVIATION...75  
FIRE WEATHER...90  
 
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