Changes to snow caused by wind abrasion or redistribution.

Credit: Sawtooth Avalanche Center

Winds play an important role in snow metamorphism.  Winds change the snow cover by physically breaking or abrading snow grains and by redistributing them from scoured to drifted locations. In wind exposed terrain, wind often dictates the spatial distribution of slabs and weak layers.  Winds can damage or erode weak layers. Slabs grow or shrink from shifting wind patterns.  Winds alter the texture and hardness of the snow surface.  They form layers of smooth, hard, closely packed particles (wind crusts or wind slabs) and rough, textured surfaces (sastrugi).  

Winds can significantly alter the distribution of both slabs and weak layers.  Credit: Crested Butte Avalanche Center

A stiff wind crust. Credit: Chugach National Forest Avalanche Information Center