Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 3
We've noted an increase in stability in the past few days, and weak snow from early November is now deeply buried at upper elevations. Dangerous human triggered avalanches running on a persistent weak layer are still possible in shady upper elevation terrain.
- Dangerous deep slab avalanches are possible, but they'll be hard to trigger.
- Very weak faceted snow pre-existed the Thanksgiving storm snow on shady upper and mid-elevation slopes.
- The weak snow was fairly shallow in the Logan Zone, so resulting slab avalanches will likely be on smooth slopes or in pockets between rocky anchors and terrain features.
- Collapsing and cracking indicate that the snow is unstable.
Shallow but loose faceted snow lurks under the Thanksgiving slab, and fresh powder is piling up on north facing slopes at upper elevations.