Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Possible
- Größe
- 1–2
It is possible to trigger a persistent slab avalanche on facets buried 1 to 3 feet deep. The two layers of concern are depth hoar on upper elevation north and east aspects and a buried crust with surrounding facets in the middle of the snowpack.
Both of these layers are becoming less reactive as the slab above them becomes less cohesive. That does not mean they are trustworthy, however.
Collapsing, cracking, or whumpfs are signs of instability, but they may not always be present. Dig into the snow and look for weak or sugary snow beneath a denser slab. If you find this, stick to slopes under 30 degrees.