Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Up to 1 foot slabs rest on top of weak facets and depth hoar in a shallow snowpack. These slabs are most likely to fail on weak near-surface facets or facets below crusts that lurk closer to the surface. Take the time to dig a quick pit to identify if this strong-over-weak snowpack structure exists. These weak layers should be easy to identify, as most of the snowpack consists of them. A persistent slab avalanche that breaks in upper weak layers has the potential to step down into deeper layers near the ground, creating a larger and more destructive avalanche.
Shooting cracks and audible collapses are indications that you've found this strong over weak snowpack structure.
(2/14/2026) Photo: Andy Bond