Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 3
A slab of cohesive snow now exists above a persistent weak layer of faceted snow on all aspects and elevations. I anticipate this weak layer to be active for a long time. Signs of instability like cracking and collapsing may be less obvious today, but make no mistake, conditions remain dangerous.
The remotely triggered avalanche in Horse Creek on Monday tells us that human-triggered sensitivity remains elevated. This avalanche is a great example of the poor snowpack structure in alpine terrain. Large, hard slabs of wind-drifted snow rest on top weak, faceted snow, and they are hanging in the balance just waiting for a trigger. Once triggered, these avalanches will break deep and wide, and be unsurvivable.
The danger is not limited to Northerly aspects, as we have started to see collapsing and poor pit results on Southerly slopes as well.