Expires:No;;418638
FXUS65 KMSO 261904
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
104 PM MDT Fri Apr 26 2024

.DISCUSSION...A trough digging across the western U.S. is bringing
some moisture to the region today. This evening the snow levels
will start to fall and snow showers will impact the mountains.
With the main energy in this trough passing to the southwest of
our area and cutting off, most of the cooler air and moisture will
affect Lemhi County Idaho and southwest Montana. 

Above the snow level, showers could produce heavy snow at rates up
to 2 inches an hour at times. Remote mountain passes like Lemhi
Pass, Skalkaho Summit, and Williams Creek Summit may pick up 
several inches of snow, but the more heavily traveled passes like 
Lost Trail Pass will pick up a quick couple inches from passing 
showers. Winter weather advisories have been issued for elevations
above 6,000 ft in the affected areas. Snow showers will occur at 
lower elevations also, but if there's any accumulation at all 
below 6,000 ft it won't be enough to warrant a winter weather 
advisory. 

This current weather system is the first wave in a cooler than
average weather pattern that will persist for at least a week. The
most significant system for the next week appears to be Tuesday
into Wednesday next week. For that system, the ensembles are
showing a 50-90 percent chance of 4 inches or more of new snow,
depending on elevation. 

&&

.AVIATION...A trough digging into the region today is causing
widespread rain showers. We only expect MVFR ceilings and
visibility due to the showers at area terminals today and tonight.
Snow levels will lower this afternoon and evening as cooler air
aloft moves into the region. While this will cause some mountain
pass level snow impacts, it is not expected to effect any major
terminals directly.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory from 6 PM this evening to 6 PM MDT 
     Saturday for Bitterroot/Sapphire Mountains...
     Butte/Blackfoot Region. 

ID...Winter Weather Advisory from 4 PM this afternoon to 6 PM MDT 
     Saturday for Eastern Lemhi County...Western Lemhi County. 

&&

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