679  
FXUS65 KMSO 312035  
AFDMSO  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MISSOULA MT  
235 PM MDT FRI JUL 31 2026  
   
DISCUSSION
 
 
KEY MESSAGES:  
 
* CRITICAL FIRE WEATHER CONDITIONS ACROSS NORTHERN ROCKIES, SATURDAY  
AFTERNOON THROUGH SATURDAY NIGHT.  
 
* CHOPPY WAVE ACTIVITY ON AREA LAKES FOR SATURDAY AFTERNOON AND  
EVENING.  
 
* RELATIVELY COOL AIRMASS IN PLACE SUNDAY THROUGH EARLY NEXT WEEK,  
BUT SUMMER WARMTH RETURNS THEREAFTER.  
 
THE WARM RIDGE OF HIGH PRESSURE CURRENTLY OVER THE NORTHERN ROCKIES  
WILL PROVIDE A FEW MORE DAYS OF HOT AFTERNOON TEMPERATURES.  
ANTICIPATE MOST LOW ELEVATIONS WARMING INTO THE 90S AND 100S (F).  
DESPITE THESE TEMPERATURES BEING IN LINE WITH RECENT TRENDS,  
REMEMBER TO TAKE TAKE FREQUENT BREAKS, DRINK PLENTY OF WATER, SEEK  
SHADE, AND NEVER LEAVING ANY PERSON OR PET IN A PARKED VEHICLE.  
THERE IS A 70 PERCENT PROBABILITY OF SHOWERS AND THUNDERSTORMS  
DEVELOPING ACROSS LEMHI COUNTY IDAHO AND PORTIONS OF SOUTHWEST  
MONTANA THIS EVENING.  
 
THE RIDGE OF HIGH PRESSURE IS ANTICIPATED TO BREAK DOWN SATURDAY  
THROUGH SUNDAY, RESULTING IN GUSTY WINDS AND LOW RELATIVE HUMIDITY  
ACROSS THE NORTHERN ROCKIES. RED FLAG CONDITIONS WILL DEVELOP AT  
MANY LOCATIONS. THOSE RECREATING ON AREA LAKES, PARTICULARLY  
FLATHEAD LAKE, WILL EXPERIENCE CHOPPY WAVE ACTIVITY SATURDAY  
AFTERNOON THROUGH LATE EVENING. A COLD FRONT IS EXPECTED TO SWEEP  
ACROSS THE NORTHERN ROCKIES SATURDAY EVENING.  
 
A RELATIVELY COOL AIRMASS IS PROJECTED TO RUSH OVER THE NORTHERN  
ROCKIES SATURDAY NIGHT THROUGH SUNDAY. GUSTY WINDS WILL RETURN  
DURING DAYTIME SUNDAY AND ONCE AGAIN INCREASE WAVE ACTIVITY ON AREA  
LAKES. HOWEVER, THE COOLER DAYTIME TEMPERATURES SHOULD KEEP  
AFTERNOON HUMIDITY A BIT HIGHER COMPARED TO SATURDAY.  
 
PREPARE FOR VERY EFFICIENT RADIATIONAL COOLING ACROSS THE NORTHERN  
ROCKIES OVERNIGHT SUNDAY. HIGH MOUNTAIN VALLEYS WILL COOL TO THE 30S  
IN MANY LOCATIONS BY MONDAY MORNING.  
 
LONG RANGE ENSEMBLES GENERALLY AGREE THAT A WARM HIGH PRESSURE RIDGE  
WILL RETURN TO THE NORTHERN ROCKIES AROUND THE MIDDLE OF NEXT WEEK.  
MODELS ALSO TEND TO AGREE THAT THE NEXT ITERATION OF OUR SUMMERTIME  
RIDGE WILL BE SEVERAL DEGREES COOLER THAN THE CURRENT RIDGE.  
 

 
   
AVIATION
 
 
HIGH DENSITY ALTITUDE WILL CONTINUE DUE TO HEAT THROUGH SATURDAY.  
SMOKE FROM AREA WILDFIRES AND INCREASING WEST WINDS ALOFT WILL BE  
THE MAIN AVIATION WEATHER IMPACTS OVER THE NORTHERN ROCKIES FOR  
THE NEXT 24 HOURS. ALSO, THERE IS A 70 PERCENT PROBABILITY THAT  
SHOWERS AND THUNDERSTORMS WILL DEVELOP 31/2100Z THROUGH 01/0400Z  
ROUGHLY BETWEEN KSMN AND KBTM. ANTICIPATE ERRATIC WIND GUSTS TO 40  
KNOTS NEAR ANY THUNDERSTORM THAT DEVELOPS. TERRAIN WILL BE  
OCCASIONALLY OBSCURED DURING THIS TIME AS WELL. A SURFACE COLD  
FRONT WILL INCREASE WIND GUSTS TO 30 KNOTS BEGINNING AROUND  
01/2000Z.  
 

 
   
MSO WATCHES/WARNINGS/ADVISORIES
 
 
MT...RED FLAG WARNING FROM 2 PM SATURDAY TO 9 PM MDT SUNDAY FOR  
DEERLODGE/WEST BEAVERHEAD...EAST BEAVERHEAD.  
 
RED FLAG WARNING FROM 2 PM SATURDAY TO MIDNIGHT MDT SATURDAY  
NIGHT FOR BITTERROOT...EAST LOLO...FLATHEAD RESERVATION...  
FLATHEAD/GLACIER PARK...KOOTENAI...WEST LOLO.  
 
ID...RED FLAG WARNING FROM 11 AM TO 8 PM PDT SATURDAY FOR  
PALOUSE/HELLS CANYON.  
 
FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY  
EVENING FOR PALOUSE/HELLS CANYON.  
 

 
 

 
 
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