Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
You could trigger a large, dangerous, persistent slab avalanche on many steep slopes currently. December storms buried weak snow that now lurks beneath 1.5-3' thick slabs. While weak layers are nothing new for us, what is unique is that our current problem continues to produce recent remote activity, implying it is well-connected and reactive. This interface of weak snow exists in many middle and upper-elevation zones. Though we haven't seen much evidence of activity on upper-elevation southerly aspects, folks outside the boundary of Targhee found unstable snow in these locations. Assume it exists on a slope until proven otherwise.
Yes, our snowpack is slowly improving, and you are less likely to trigger a slide than a week ago. But continued reports of dramatic collapses and poor snowpack test scores are solid evidence that the risk remains too high—and the consequences too great.
(12/12/2023) A recent avalanche showing a crown depth taper from shallower new snow to a large, 3-foot-deep avalanche.