Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–3
There are two primary persistent weak layers to keep in mind. The first exists under storm snow from early January and the second lies near the base of the snowpack. Avalanches on either of these layers will be large and destructive.
Over the weekend, a cluster of slab avalanches released in the Smoky Mountains near Baker Creek (photo, photo) and in Boulder Mountains near the N. Fork of the Big Wood. These slides share characteristics that point toward where triggering a slide is most likely again today.
- Wind-loaded terrain: Slopes where the wind formed drifts and/or stiffened the snow surface.
- Steeper slopes: Slopes around 35-45 degrees in steepness.
- Southerly facing terrain: Crusts and facets just below the recent storm snow appear to be slower to stabilize on SW-S-SE aspects than the weak layers on shadier slopes.
ADDITIONAL DISCUSSIONRecent light snowfall and moderate wind built sensitive cornices and small wind slabs near exposed ridgelines. Cracks shooting from your boards or sled are the best clue that you’ve found a sensitive slab.