Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2–3
Persistent slab avalanches will break an average of 2 to 4 feet deep (much deeper on drifted terrain) on buried persistent weak layers, and may run naturally today as solar input warms the snow surface on sunny aspects. These slabs have settled and are not often showing obvious warning signs before large and destructive avalanches release. The north half of the compass has the most fragile weak layers buried in the upper and lower snowpack (see videos 1 & 2) and is most likely to produce natural releases, remote triggers from flat terrain, widely propagating, and destructive avalanches. Recent natural avalanche activity suggests higher elevation southerly terrain contains problematic structures as well. Manage today's persistent slab problem by avoiding travel on or below terrain steeper than 30 degrees on problematic aspects, including runout zones.
(2/21/2026) A natural avalanche on the east side of Mount Crested Butte. You can trigger a dangerous avalanche below treeline. The potential avalanche size grows as you climb up in elevation.