Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1.5–2.5
Cohesive slabs 1-3 feet deep sit on top of our shallow, weak faceted snowpack on Northerly and East aspects near and above treeline. Higher elevation slopes above treeline continue to be the most dangerous, as the slabs are the thickest and most consistent. Near treeline slopes have taken more heat in general, but some will still harbor this unstable setup of strong over weak. Obvious red flags like cracking and collapsing may not be present in travels and tracks on a slope is not an indication that it's safe. Avalanches of this variety could be remotely triggered, propagate widely, step down, or run near the ground. They could also easily be large enough to injure or bury you.
Most persistent slab avalanches will fail like this one, close to the ground, taking with it most of the season's snowpack and will easily be big enough to bury you.
(2/22/2026)