Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 4
- Although unlikely, there is lingering potential on some isolated slopes with poor snow structure for large and destructive hard slab avalanches that fail on a buried persistent weak layer near the ground. We are becoming less concerned, but the problem may still exist in outlying upper-elevation terrain, especially on northerly-facing slopes in isolated rocky terrain with shallow snow cover.
- Another potential buried persistent weak layer consisting of small sugary grains of faceted snow exists on the interface of last year's snow surface and the heavy snow from the New Year's storm. Slab avalanches today, up to three feet thick, might fail on this buried persistent weak layer.