Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1.5–2.5
A mix of depth hoar, facets, and faceted crusts buried 2 to 3 feet deep are the weak layers for this avalanche problem. Their sensitivity to triggering varies from reactive to stubborn across the forecast area. Snowpack structure is variable due to early-season droughts, record-warm temperatures, rain, and past extreme wind events. As a result, expect inconsistent feedback as you move across aspects, elevations, or even different parts of the same slope. Cracking and collapsing are obvious signs of instability, but those early warning signs are decreasing and may not occur before an avalanche releases. Persistent slabs can break far above you and remotely from lower-angle terrain connected to steeper terrain. The most reliable way to manage this problem is by choosing slopes less than 30 degrees. Northerly-facing slopes below ~10,500ft offer a reduced risk of triggering, as stronger crusts often cap weak layers.
A large, remotely triggered avalanche that broke on weak layers near the ground last Monday above West Brush Creek. (1/6/2026)