The Winter Weather Advisory for snow... and blowing snow is now in effect from 5 PM this afternoon to 5 PM MST Saturday.

Timing and main impact: snow will develop this evening and increase after midnight as a cold front sweeps through the area. The cold front should reach Chief Joseph Pass shortly after midnight and West Yellowstone between 5 am and 6 am MST. Snow will turn to snow showers Saturday afternoon. The worst conditions will be associated with the cold front as snow and gusty winds combine to produce very poor visibilities. Expect difficult travel conditions... especially over mountain passes.

Snow accumulations: snow accumulations of 2 to 5 inches are likely in the valleys and mountain passes with 5 to 8 inches likely in the mountains.

Winds and visibility: expect gusty southwest winds 15 to 25 mph with visibilities less than a mile at times. However with the cold front expect northwest winds 25 to 35 mph with gusts to possibly 50 mph and visibilities below a quarter of a mile.

Locations affected include: Targhee Pass... West Yellowstone... Raynolds Pass... Big Hole Pass... Chief Joseph Pass... Monida Pass.