Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
You could trigger an avalanche where cohesive slabs of snow sit over weaker snow on slopes steeper than about 35 degrees. The most dangerous slopes are steep open start zones that recently received wind drifting. Strong winds even stiffened snow on open slopes below treeline, so look for and avoid snow surfaces that appear wavy, textured, or pillowy. You can reduce your chances of triggering an avalanche by avoiding common trigger points, such as convex rollovers, rocky outcrops, below cliff-bands, or the edges of slopes where the margins of a slab are the thinnest.
At lower elevations, the surface slab continues to deteriorate. You can trigger a loose avalanche on steep convex features and near rocky outcrops where the surface snow has lost cohesion.