Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
Snowmobilers and skiers can trigger large hard slab avalanches failing on weak snow that formed during December. These slabs are 1-2 feet deep above 9,000’ and about 1 foot deep below that. Most aspects (shaded and sunny) remain suspect due to the widespread nature of the January 4th persistent weak layer. Slabs could be triggered from a distance, by the first rider, or even wait until the last person in your group is riding the slope to release. Steep, rocky, and unsupported terrain features are most likely to produce an avalanche at the moment. However, given the well connected nature of the weak layer, it is possible for avalanches to propagate long distances across slopes. Because of this, avoid terrain that is connected to avalanche paths, beware of what lies above you, and give runout zones a wide margin. Avoid terrain traps such as steep cutbanks and gullies. Even a small avalanche in a terrain trap can have serious consequences. For the time being, riding low angle terrain with little consequence is the best way to mitigate this problem.
(1/20/2024)
This avalanche depicts the terrain to avoid that is very steep and dangerous.
Photo: Matthew Tousignant