Avalanches of wind drifted snow are possible on may upper and mid elevation slopes where overnight winds deposited drifts of last weekend's fresh snow. Today's new snow will obscure the older drifts, while west and then northwest winds today will build new ones. People are likely to trigger wind slab avalanches on some steep upper elevation slopes where drifts formed on weak, sugary or faceted snow. In more sheltered terrain, loose sluffs and shallow soft slabs of new snow are possible because the older snow underneath is very weak, faceted, and loose.

During the extended November dry spell, the shallow snow on the ground was subjected to a significant temperature gradient and resulting sublimation caused the snow on many slopes to become sugary, non-cohesive, faceted, and very weak. Drifted snow is a wind slab and when these stiffer, more cohesive slabs develop on top of weak, sugary, faceted snow they are unstable. Avalanches failing on a persistent weak layer can be very sensitive, and they might be triggered remotely, from a distance, or worse from below!

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