Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
You may be able to trigger 1-3 foot thick slabs in wind-loaded terrain near and above about 8500'. Some slabs overlie crusts and/or thin layers of weak, faceted snow and could break wider than expected. Triggering these large avalanches is most likely on slopes approaching or exceeding about 40 degrees in steepness.
Yesterday, NW-N-NE wind was moving snow on ridgetops. Look for smooth pillows below ridgelines and cornices as well as on the sides of cross-loaded gullies. In the craggy Sawtooth Mtns, slabs commonly form in cirques below large cliff faces and on the aprons of large chutes and couloirs. Dunes and ripples on the surface are clues that the wind has been at work transporting snow.
Falling cornices (photo below/at right) can be great triggers for the wind slabs below them. Hard wind slabs sound hollow, like a drum, and behave unpredictably; they can break above you and wider than expected. You may or may not experience snowpack cracking or collapsing—clear signs of unstable conditions—before triggering a wind slab avalanche.
(1/14/2026) Large avalanche triggered by cornice fall. Photo: Sawtooth Avalanche Center