Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–2.5
You're unlikely to trigger a very large avalanche that fails on deeper weak layers buried up to 3 feet at middle and upper elevations. Rapid settlement and increasing temperatures create some uncertainty regarding the reactivity of the new slab sitting on these weak layers. At lower elevations where the snowpack is thinner and temperatures are warmer, avalanches will be possible. This layer can be found in pits and can still show propagation but is deep and less likely to be impacted. While the likelihood is decreasing, the consequences of triggering a very large avalanche on this layer remain high. The best way to manage this problem is to give yourself a safety margin around very steep slopes while the snowpack continues to adjust.
(2/11/2025)
This layer of concern now has another 3 feet of snow loading it...
Photo: Bridger-Teton Avalanche Center