Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 2
The snowpack structure is fairly complicated right now. A PWL (persistent weak layer) of faceted snow is buried 1-2' down. Below the post-Christmas storm lies a very slick and - in many areas - very thick Christmas Eve rain crust (CERC) essentially capping the poor structure below. The structure has shown its cards, but only in the upper Cottonwood Canyons near Alta and Snowbird..and only on Sunday. These were 2-3' deep on very steep north facing slopes above 10,000'.
We've heard of nothing since. Triggering a hard slab on this structure is unlikely, but not impossible. I'd still avoid steep, thin rocky terrain where the crust may be thinner.