Persistent Slabs
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Likely
- Tamaño
- 2
The November snow in upper elevation avalanche starting zones before the weekend storm is extremely weak and sugary due to its shallowness and sustained cold temperatures. Heavy snow and drifting from last weekend’s storm overloaded this weak faceted snow (now a persistent weak layer), and several large avalanches up to 3 feet deep and several hundred feet wide occurred in the last few days.
We've noted increasing stability in recent days, and avalanches are generally unlikely on slopes that were bare of snow or had very shallow snow cover before last weekend's storm
- Avalanches failing on a persistent weak layer could be triggered remotely, from a distance, or below.
- Cracking and collapsing (or whumpfs) are definite signs of instability.