Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Likely
- Dimensione
- 1.5–2.5
Cohesive slabs about 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 will be the most dangerous today, where the slabs are the thickest and most reactive. Near treeline slopes have taken more heat in general but some will still harbor this unstable setup, in particular northerly slopes. Obvious red flags like cracking and collapsing are signs that you've found this setup for an avalanche, but these signs may not be present everywhere. Avalanches of this variety could propagate widely, step down or run near the ground, and they could easily be large enough to bury you.
This natural persistent slab avalanche (size 2) occurred yesterday morning on an ENE slope of Kachina Peak.
(2/26/2026) Photo: Charlie Harrison