Feet of snow expected for western Montana mountains
Avalanche danger generally rises when storms deliver significant snowfall to the mountains. The problems are manifold: Fresh powder can take a few days to bond to older snow it accumulates on, leading to storm-slab avalanches; light, unconsolidated dry powder can slough down steep slopes; and the weight of new snow can overload weak layers lower in the snowpack, leading to large avalanches of both new and old snow.
Source: ravallirepublic.com
