Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–3
Weak basal stucture in the form of facets, decomposing crusts, and buried surface hoar are present 2-3 feet down in the snowpack. This avalanche problem can be found in all three mountain ranges but will be more easily triggered in the Purcell Range where the snowpack is thinner. On Thursday, our stability tests showed consistent failures that showed the potential to propagate across slopes. Triggering an avalanche on one of these weak layers is possible and could create a large and destructive avalanche if triggered. These conditions were found in the Purcells and the Cabinets in stability tests this week and may become more easily triggered as additional weight is added to the snowpack in the form of rain.
Jan 25th, 2024 ENE Aspect 5600' Purcell Mountains. Failure on Basabl Facets with Moderate force. Photo: Liz Figgins