Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2
Although the likelihood is decreasing, it is still possible to trigger an avalanche on a buried weak layer of faceted snow. You are most likely to encounter this problem on steep, wind drifted slopes near and above treeline that face the north half of the compass. In these areas, hard slabs of wind drifted snow from the last storm event are sitting on top of weak facets that formed at the old snow surface. Human triggered avalanches failing on this weak layer would be up to 2 feet deep and could certainly ruin your day if not more. In some cases, triggered avalanches may step down below the Christmas rain crust causing a deeper and much more dangerous avalanche. This is a low probability, high consequence scenario. The only way to truly avoid the problem is to avoid slopes steeper than 30 degrees. But if you are compelled to venture into north facing avalanche terrain, bite off small pieces first. Avoid steep convexities and areas of rocky, more radical terrain.
In the video below, pro observer Tim Mathews gives his perspective on the current snowpack structure.
