586  
FXUS65 KMSO 140825  
AFDMSO  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MISSOULA MT  
225 AM MDT FRI AUG 14 2026  
   
DISCUSSION  
 
KEY MESSAGES:  
 
- ROUNDS OF SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAIN,  
THE POTENTIAL FOR DEBRIS FLOWS, AND GUSTY WINDS (MAINLY WESTERN  
MONTANA) THROUGH TODAY.  
 
- TEMPORARY RELIEF FROM SMOKE WITH EASTERLY WINDS.  
 
- GRADUAL WARMING AND DRYING TREND THIS WEEKEND, DAILY  
THUNDERSTORM THREAT CONTINUES.  
 
SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS CONTINUED TO  
REDEVELOP AND MOVE OVER WESTERN MONTANA AND NORTH-CENTRAL IDAHO  
DURING THE OVERNIGHT HOURS INTO EARLY THIS MORNING. BRIEF HEAVY  
RAINFALL AND OCCASIONAL LIGHTNING OCCURRED WITH THESE STORMS.  
LINGERING SHOWERS WILL CONTINUE TO STREAM OVER WESTERN MONTANA  
THROUGH MID-MORNING.  
 
THIS AFTERNOON, SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WILL  
IMPACT THE NORTHERN ROCKIES AND WILL LIKELY BRING ISOLATED  
ACTIVITY THROUGH THE OVERNIGHT ONCE AGAIN. THE MAIN THREAT WITH  
THESE THUNDERSTORMS WILL BE BRIEF HEAVY RAINFALL. YESTERDAY  
AFTERNOON, THUNDERSTORMS PRODUCED UP TO 0.40 INCHES PER HOUR,  
WHICH CAN BE EXPECTED WITH THE THUNDERSTORMS TODAY. THE STRONGEST  
STORMS ARE EXPECTED BETWEEN 3 PM AND 9 PM, BRINGING A THREAT FOR  
DEBRIS FLOWS AND EXCESSIVE RUNOFF TO FLOOD-PRONE AREAS OF NORTHERN  
LEMHI COUNTY AND BURN SCARS IN THE SOUTHERN BITTERROOT VALLEY. A  
FLASH FLOOD WATCH MAY BE NEEDED TO HIGHLIGHT AREAS AT MOST RISK  
FOR IMPACTS THIS AFTERNOON AND EVENING. GUSTY AND ERRATIC WINDS  
BETWEEN 30-40 MPH WILL ALSO BE A THREAT, THAT COULD BLOW AROUND  
UNSECURED OBJECTS AND BRING MINOR TREE DAMAGE.  
 
A RIDGE OF HIGH PRESSURE WILL REBUILD OVER THE NORTHERN ROCKIES  
THIS WEEKEND INTO EARLY NEXT WEEK. PERSISTENT SOUTHWEST WINDS  
ALOFT WILL CONTINUE TO BRING MOISTURE INTO THE REGION, KEEPING  
ATMOSPHERIC MOISTURE HIGH. THIS PATTERN WILL SUSTAIN DAILY CHANCES  
FOR AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH NEXT WEEK,  
PREVENTING A FULL RETURN TO DRY CONDITIONS. WILDFIRE SMOKE WILL  
REMAIN AN ONGOING CHALLENGE, WITH AIR QUALITY EXPECTED TO DEGRADE  
SLOWLY THIS WEEKEND AS SOUTHWEST WINDS TRANSPORT SMOKE PLUMES FROM  
SOURCE FIRES IN EASTERN WASHINGTON AND OREGON.  
 
 
   
AVIATION  
SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS WILL  
CONTINUE TO STREAM OVER WESTERN MONTANA AND NORTH-CENTRAL IDAHO  
THROUGH 14/1500Z THIS MORNING. SHOWER AND THUNDERSTORM ACTIVITY  
WILL REDEVELOP THIS AFTERNOON AND EVENING, BRINGING A THREAT FOR  
FREQUENT LIGHTNING, BRIEF HEAVY RAINFALL, AND GUSTY, ERRATIC WINDS  
UP TO 35 KTS TO ALL AVIATION SITES ACROSS THE NORTHERN ROCKIES.  
HOWEVER, KMSO, KHRF, KBTM, AND KSMN WILL HAVE THE HIGHEST CHANCE  
FOR THE STRONGEST STORMS BETWEEN 14/2000Z AND 15/0200Z THIS  
EVENING.  
 
PERSISTENT EASTERLY WINDS HAVE LIMITED THE IMPACTS DUE TO SMOKE  
FROM REGIONAL AND LOCAL WILDFIRES, BUT THIS IS LIKELY TO CHANGE  
THIS WEEKEND AND EARLY NEXT WEEK, WHEN A SOUTHWEST WIND PATTERN  
RETURNS TO THE NORTHERN ROCKIES.  
 
 
   
MSO WATCHES/WARNINGS/ADVISORIES  
 
MT...NONE.  
ID...
 
 
 
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