Heavy mountain snowfall will continue to fall through Wednesday on terrain above 4,000'. The new snow is resting on a variety of surfaces that will be prone to avalanching on all aspects. New snowfall is most intense in the West and East Cabinets with snotel sites in the Purcell Range showing significantly less snowfall at this time.

Strong winds out of the West and Southwest have created drifting and slabs on North and East facing terrain. Stiff pockets of drifted snow will be evident and crack easily near ridglines and exposed gullies. Steep chutes and leeward terrain are loaded in with fresh snow and packed into a nice, dense slab. Expect these slabs to be easily triggered.

There are two significant weak layers in the snowpack that we are monitoring that will become sensitive to triggers as the storm snow piles up and adds weight to the snowpack. In the East Cabinets and Purcell Range I have been finding buried surface hoar in sheltered timber locations below 7,000' and in the West Cabinets there is a very thin crust overlying tiny facets. Both are likely to be reactive with potential rising as additional snow and weight adds stress to these layers.

Photo depicting weak crust layer at 6,600' on Smith Mt. An additional foot of snow has been added to the snowpack since photo was taken.