786  
FXUS65 KMSO 301937  
AFDMSO  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MISSOULA MT  
137 PM MDT MON JUN 30 2025  
   
DISCUSSION
 
 
KEY MESSAGES:  
 
- HOT TEMPERATURES THROUGH WEDNESDAY  
 
- GUSTY STORMS IN LEMHI COUNTY & SW MONTANA TUESDAY AFTERNOON  
 
- THUNDERSTORMS ACROSS THE REGION EACH DAY WEDNESDAY ONWARD  
 
HOT DAYTIME TEMPERATURES WILL PERSIST THROUGH WEDNESDAY AS HIGH  
PRESSURE REMAINS OVER THE NORTHERN ROCKIES. WARM OVERNIGHT LOWS  
ARE ALSO EXPECTED IN THE LOWER VALLEYS OF NORTH-CENTRAL IDAHO,  
WHERE A HEAT ADVISORY IS IN EFFECT.  
 
MOISTURE WILL BEGIN INCREASING ACROSS LEMHI COUNTY AND SOUTHWEST  
MONTANA ON TUESDAY, WITH HIGH-RESOLUTION MODELS NOW INDICATING  
POTENTIAL THUNDERSTORM DEVELOPMENT. ANY STORMS THAT FORM ARE  
EXPECTED TO BE HIGH-BASED AND WILL LIKELY PRODUCE GUSTY OUTFLOW  
WINDS.  
 
THE RIDGE SHIFTS EASTWARD WEDNESDAY, SETTING UP SOUTHWEST FLOW- A  
CLASSIC THUNDERSTORM PATTERN FOR CENTRAL IDAHO AND WESTERN  
MONTANA. WITH THE RECENT HEAT AND DRY CONDITIONS, STRONG WINDS  
WILL BE THE MAIN THREAT AT FIRST. MACHINE LEARNING AND AI MODELS  
CONTINUE TO INDICATE SOME RISK OF SEVERE STORMS WEDNESDAY.  
 
MODEL GUIDANCE AGREES THAT SOUTHWESTERLY FLOW WILL PERSIST THROUGH  
THE WEEK AND INTO THE WEEKEND, BUT DIFFERS ON THE EXACT TIMING AND  
STRENGTH OF THUNDERSTORM-PRODUCING SHORTWAVES. THIS PATTERN FAVORS  
DAILY THUNDERSTORMS, SOME POTENTIALLY STRONG WITH GUSTY WINDS,  
HEAVY RAIN, AND HAIL. IF YOU HAVE OUTDOOR PLANS, STAY WEATHER-  
AWARE AND HAVE A PLAN IN CASE A STORM APPROACHES.  
 

 
   
AVIATION
 
HOT DAYTIME TEMPERATURES WILL CONTINUE UNDER STRONG  
HIGH PRESSURE, WHICH MAY CONTRIBUTE TO DENSITY ALTITUDE CONCERNS.  
HIGH-RESOLUTION MODELS NOW INDICATING POTENTIAL THUNDERSTORM  
DEVELOPMENT ACROSS LEMHI COUNTY AND SOUTHWEST MONTANA TUESDAY  
AFTERNOON, WHICH MAY IMPACT KSMN AND KBTM. ANY STORMS THAT FORM  
ARE EXPECTED TO BE HIGH-BASED AND WILL LIKELY PRODUCE GUSTY  
OUTFLOW WINDS.  
 

 
   
MSO WATCHES/WARNINGS/ADVISORIES
 
 
MT...NONE.  
ID...HEAT ADVISORY UNTIL 9 PM PDT TUESDAY FOR LOWER HELLS  
CANYON/SALMON RIVER REGION...OROFINO/GRANGEVILLE REGION.  
 

 
 

 
 
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