Deep Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–3
Backcountry travelers could impact weak, faceted snow near the base of the snowpack in steep north facing terrain above an elevation of 9,000 feet. Large triggers, such as snowmobiles, are more likely to cause failure of this basal weak layer, and previous tracks are not an indication of stability. Large destructive slab avalanches that fail on this deeply buried, persistent weak layer could reach five feet in depth and are likely to be unsurvivable.