The Gallatin National Forest Avalanche Center is issuing a Backcountry Avalanche Warning for the Southern Madison and Southern Gallatin Ranges and the Lionhead area near West Yellowstone. 

About one foot of new snow rests on an extremely weak layer of faceted snow crystals. Today the avalanche danger is HIGH on all slopes. Areas of unstable snow exist. Natural and human triggered avalanches are very likely.

Avalanche terrain including avalanche run-out zones should be avoided.

For more info about the avalanche danger, click here.