Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1.5–2.5
Weak layers buried 2-3 feet deep continue to haunt the snowpack across all aspects and elevations. The main concern is the Feb 18th layer composed of crusts and facets. You can find unstable results in stability tests pretty much everywhere, with increased reactivity on southerly aspects with a weak facet/crust combination. The recent warming trend has not been sufficient enough to stabilize these layers. Triggering a large avalanche remains possible, especially on previously wind loaded terrain. Conservative terrain management is necessary during this low probability, high consequence avalanche problem. Avalanches failing on layers deeper than 3 feet are also possible on weak basal facets and depth hoar. Terrain with an increased likelihood of triggering a persistent slab include:
- Shallow snowpack: Weaker buried layers of snow .
- Wind-affected: Terrain where wind has formed firm, cohesive slabs of snow.
- Steep: Over 35° slopes.
Mocassin Basin 9500' E aspect
Photo: Cory Beattie