Although we may see slush and rain in the valleys on Tuesday, mountain passes could see 2 - 5 inches of snow accumulation by Wednesday morning in southwest Montana.

According to the National Weather Service:

Winter Weather Advisory in effect from 6 am Tuesday to 6 am
MDT Wednesday for elevations above 5000 feet...which
is in effect from 6 am Tuesday to 6 am MDT Wednesday.

Locations... Big Hole Pass... Chief Joseph Pass... Dillon...
Monida Pass... Kings Hill Pass... Flesher Pass... MacDonald
Pass... Rogers Pass... Norris Hill... Raynolds Pass... Boulder
Hill... Elk Park Pass... Homestake pass... White Sulphur
Springs... Battle Ridge Pass... Bozeman Pass... Targhee Pass...
West Yellowstone.

Snow accumulations... 2 to 5 inches.

Impacts/timing... a Pacific weather system will produce
accumulating snow mainly at and above pass level starting early
Tuesday and continuing through Tuesday night.

Snow accumulation on roads is most likely during the morning and evening hours. 

Partial to complete snow melt is possible on Road surfaces during daylight hours, but periods of heavy snow will produce localized accumulation with reduced visibility.

(photo Michelle Wolfe/KMMS)