Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Possible
- Dimensione
- 2–2.5
Slabs that formed in early February rest above a variety of ugly, widespread, weak layers (facets, surface hoar, crusts, and combinations). The snowpack is gradually stabilizing, but the steady stream of snowfall is maintaining the chance of triggering slides. You are most likely to trigger a dense, 2-4 foot thick avalanche where:
- Any part of the slope you are on or connected to is steeper than about 35 degrees
- The slope faces the northern 2/3 of the compass
- The slab is less than about 3' thick—relatively shallower spots may exist where the wind frequently blows, and the slab is not uniformly thick.
Before triggering an avalanche, you may or may not experience obvious signs of instability like snowpack cracking and collapsing or whumpfing. Persistent Slabs can release in surprising ways, break wider than expected, and release above or hundreds of feet away from where they are triggered. We can't assume tracks on a slope mean it is safe; several people could descend a slope before triggering an avalanche.