Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1.5–2.5
This week's storms brought 3-5 feet of accumulating snow to the mountains in this zone. Snow totals were on the low end of forecasts initially, but this area really caught up over the past two days. You'll be most likely to find instabilities within the new snow on slopes where the wind has been at work. Thinner wind slabs from recent winds will be the most reactive, but are likely to be on the smaller side. Slabs that fail at the base of the new snow will be much larger, easily big enough to bury you.
Look for signs that the wind has been work to help you identify recent wind slabs. Textured snow surfaces, smooth pillows below ridgelines and on the sides of gullies, and fresh cornices are all good indicators of wind transport and deposition. Cracking in fresh drifts is a sign you've found a reactive slab, but don't expect to get much direct feedback on instabilities at the base of the new snow. Reactive slabs will be most widespread in upper elevation terrain, but you may find similar slabs in exposed middle elevation terrain as well.
Slides triggered in the recent snow can step down to deeper weak layers, producing very large, unsurvivable avalanches. More on this in the Persistent Slab problem section below.
(3/13/2026) Photo: West Central Montana Avalanche Center