Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–2.5
Weak layers formed earlier in the season are buried beneath hard slabs 2-3 feet deep. In heavily wind affected terrain, these slabs could be over four feet deep. These weak layers have persisted over time meaning that they can be triggered without additional snowfall or wind adding stress. Slopes where the overlying slab is thinner and easier to impact will be where human triggered avalanches are most likely. This includes heavily wind affected and scoured slopes in the alpine as well as steep, shallow slopes around creeks and gullies. The last human triggered persistent slab avalanche was three days ago in Maverick Creek.
A rider had a very close call the day before yesterday, December 31, 2025. This avalanche illustrates the difficulty in pinpointing where you can trigger deeper weak layers. Note that this seems to be a shallow area, making it easier to trigger a weak layer.