Deep Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Possible
- Dimensione
- 2
The Dec. 11 persistent weak layer remains buried in our snowpack and is widespread in near and below treeline areas and more isolated in above treeline areas. The lower part of our snowpack structure remains weak with this faceted layer buried around 1.5 to 2.5 feet deep below the snow surface. The likelihood of triggering an avalanche has decreased and we have had no known avalanches occur in the last 2 days. With that said, triggering a large avalanche remains possible as this weak layer could take a long time to gain strength. Unfortunately, the weak layer will gain strength at different rates at different locations- with whumpfing, cracking, and unstable snowpack test results reported in some areas with few or no signs of instabilities reported from other areas. The Dec 11 PWL has already caused large avalanches, with wide propagation, and remote triggering-and that will continue to remain possible.
Conservative terrain choices remain the best way for managing a persistent slab avalanche problem. Conditions are very good on low angle sub 30 degree terrain and remain a great way to avoid this avalanche problem. Be aware of connected terrain above, below, or to the side of you or your group that could be remotely triggered. Persistent slabs are notorious for behaving in unpredictable ways. Wide propagation, large avalanches, mid slope avalanches, and avalanches on slopes that already have tracks could occur.
