Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Unlikely
- Größe
- 3
Although increasingly unlikely, hard slab avalanches failing on a buried persistent weak layer could be large and life-threatening. In January, heavy snow and drifting overloaded slopes plagued by a widespread persistent weak layer that formed in the December dry spell. Rapid warming over the weekend caused some slopes to be unstable and there were a few large avalanches. Cooling today will increase snow stability, but dangerous avalanches are still possible in steep rocky terrain with shallow snow and poor snowpack structure, a stiff slab on top of a layer of weak, sugary, or faceted snow.
- Avalanches still might be triggered remotely, from a distance, or even from below!
- Audible collapsing (or whumpfs), cracking, and recent avalanches are obvious signs of instability. However, these red flags may not be present when avalanches failing on a persistent weak layer occur.