Relatively short-lived weaknesses within new-fallen or windblown snow.

A slab avalanche that failed on a storm snow weak layer during heavy snowfall.  Credit: Flathead Avalanche Center

Slab avalanches can fail on a variety of precipitation particles that form layers within storm snow. Unlike persistent weak layers, these instabilities have a relatively short lifespan, generally ranging from a few hours to a few days. Storm snow weak layers are associated with Storm Slab and Wind Slab avalanche problems. There are dozens of forms of precipitation particles; the ones defined here are some of the most common weak layers associated with storm snow failures.

Storm snow grains under magnification. Credit: The International Classification for Seasonal Snow on the Ground / JSSI