Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2
The primary avalanche concern is a weak layer of faceted snow from the December dry spell, buried on 12/25, about a foot below the surface on northwest, north, and east aspects. While this weak layer is widespread, the overlying slab required to create an avalanche is not. This problem is most pronounced near the treeline in areas where previous drifting has created an overlying slab. Slopes with a northerly component to their aspect are most suspect. Places like Exxon’s Folly (or anything resembling that) come to mind. Avalanches triggered 1–2 feet deep could potentially entrain enough snow to step down to basal facets near the ground. If you find a slab over this weak layer, dial back your slope angles to less than 30°. Curious about low danger above treeline? Read the additional information below for more details.