Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 1–2
Triggering a slab avalanche on older, persistent weak layers has become unlikely. Poor structure still exists and the weak snow near the ground did not disappear. It would not be impossible to trigger an avalanche in steep (greater than 35 degrees) terrain, especially on northern aspects where the snow is over rocks.
You will not see any warning signs like cracking or collapsing. Your best way to manage this avalanche problem is to avoid the terrain where it is most likely hiding. The video to the right, highlights where you are most likely to find a persistent slab avalanche.