927  
FXUS65 KMSO 150836  
AFDMSO  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MISSOULA MT  
236 AM MDT WED OCT 15 2025  
   
DISCUSSION  
 
KEY MESSAGES:  
 
- SEASONABLE TEMPERATURES WITH VALLEY RAIN SHOWERS AND LIGHT  
MOUNTAIN SNOWFALL TODAY INTO THURSDAY FOR SOUTHWEST MONTANA.  
 
- TRAVEL IMPACTS ARE POSSIBLE OVER MOUNTAIN PASSES EARLY NEXT  
WEEK DUE TO SNOWFALL.  
 
A MIX OF CLOUD COVER AND FOG ARE COMMON ACROSS THE REGION THIS  
MORNING DUE TO THE LINGERING COOL AIRMASS AND MOISTURE. SHOWERS  
WILL AGAIN ENTER THE REGION FROM THE SOUTH TODAY WITH HIGHEST  
SHOWER CHANCES ALONG THE DIVIDE. SNOW LEVELS ARE RISING SO THESE  
SHOWERS SHOULD PREDOMINATELY BE VALLEY RAIN AND MOUNTAIN SNOW.  
HIGH RESOLUTION MODELS ARE TRENDING TOWARD PRECIPITATION SHIFTING  
EASTWARD TONIGHT WITH THE MAIN FOCUS BEING EAST OF THE DIVIDE.  
LOCATIONS NORTH AND WEST WITH LESS CLOUD COVER AND CALM WINDS HAVE  
INCREASED CHANCES FOR AREAS OF VALLEY FOG TO DEVELOP, ESPECIALLY  
IN PLACES LIKE THE FLATHEAD AND MISSION VALLEYS.  
 
ON THURSDAY, AN UPPER-LEVEL RIDGE BEGINS TO BUILD OVER THE  
REGION, LEADING TO EXPANDING SUNSHINE. HIGH TEMPERATURES ARE  
FORECAST TO REBOUND INTO THE UPPER 50S AND LOW 60S FOR MOST VALLEY  
LOCATIONS.  
 
THE UPPER-LEVEL PATTERN SHIFTS TO NORTHWESTERLY OF FRIDAY WITH  
SHOWERS AND SLIGHTLY BELOW AVERAGE HIGH TEMPERATURES. HEADING INTO  
THE WEEKEND, MODEL GUIDANCE NOW INDICATES A BRIEF RIDGE OF HIGH  
PRESSURE BUILDING INTO THE REGION WITH MILD TEMPERATURES AND  
ISOLATED SHOWERS ON SATURDAY AND SUNDAY BEFORE THE MAIN SYSTEM  
ARRIVES LATE SUNDAY INTO MONDAY  
 
THE LATEST NBM GUIDANCE AND ENSEMBLE MODEL DATA CONTINUE TO SHOW  
A DEEP AND COLD TROUGH DIGGING SOUTH ALONG THE WEST COAST AND INTO  
OUR REGION FROM MONDAY INTO TUESDAY. THERE ARE TIMING AND  
STRENGTH DIFFERENCES WITH THIS TROUGH, BUT THERE IS INCREASED  
POTENTIAL FOR COOLER TEMPERATURES AND BELOW-AVERAGE SNOW LEVELS.  
 
POTENTIAL IMPACTS FROM THE EARLY WEEK SYSTEM INCLUDE:  
 
- WIDESPREAD PRECIPITATION: WIDESPREAD RAIN IS EXPECTED IN THE  
VALLEYS BEGINNING LATE SUNDAY OR MONDAY.  
 
- MOUNTAIN SNOW: SNOW LEVELS ARE FORECAST TO LOWER SIGNIFICANTLY  
THROUGH THE DAY ON MONDAY, POTENTIALLY FALLING TO NEAR PASS  
LEVELS (4500-5500 FEET). THIS COULD RESULT IN ACCUMULATING SNOW  
FOR MOUNTAIN PASSES LIKE LOLO, LOOKOUT, AND MARIAS, LIKELY  
CAUSING TRAVEL IMPACTS.  
 
 
   
AVIATION  
LOW CLOUDS AND FOG HAVE SPREAD OVERNIGHT, FILLING MOST  
OF THE VALLEYS THIS MORNING. THIS HAS CREATED MVFR CEILINGS AT  
AREA AIRPORTS, A CONDITION THAT WILL LIKELY CONTINUE FOR MOST OF  
THE MORNING. SHOWERS ARE ALSO APPROACHING FROM THE SOUTH AND ARE  
EXPECTED TO REACH THE CONTINENTAL DIVIDE TODAY, BRINGING REDUCED  
VISIBILITY AND OBSCURED MOUNTAIN TERRAIN INTO TONIGHT. AS SKIES  
CLEAR BEHIND THE SHOWERS, IT'S POSSIBLE FOR FOG AND LOW CLOUDS TO  
REDEVELOP, ESPECIALLY IN NORTH-CENTRAL IDAHO AND NORTHWEST MONTANA  
ON THURSDAY MORNING.  
 
 
   
MSO WATCHES/WARNINGS/ADVISORIES  
 
MT...NONE.  
ID...NONE.  
 
 
 
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