The area affected includes The Selkirk, Purcell, Cabinet and St. Joe Mountains and the St. Regis Basin.
One to three feet of new heavy snow is sitting atop a base of low-density snow which will not support the additional load.
Avalanches, both natural and human caused, are likely on all aspects above 4,000 feet.
Travel in avalanche prone terrain is not recommended. This warning does not include ski areas where regular avalanche control is performed.