Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2.5
There are several weak layers buried within 3 ft of the snow surface. The most recent storm from 12/21-22 has placed a continuous slab on top of these persistent weak layers, creating the necessary conditions for avalanches. Areas where the wind has stiffened this new snow into thick slabs are of particular concern.
A layer of near surface facets and surface hoar was buried in early to mid December. This layer is about 1.5 feet or so below the surface of the snow and is very reactive (touchy). The distribution of this layer remains uncertain but is suspected to be widespread. The November 27 layer is widespread and is now buried around a meter deep at the upper elevations.
Avalanches may be triggered remotely—from gentler terrain above, below, and to the sides of steep slopes.
(12/22/2022)
Natural avalanche activity on surface hoar in the Greys
Photo: Antonioli