Wind Slabs
- Alpin
- Limite forestière
- Sous la limite forestière
- Probabilité
- Possible
- Taille
- 1–2
On Friday I observed light to moderate blowing snow out of the west at ridge top near treeline. Wind slabs were minimal although I did trigger a small wind slab avalanche (D1, east aspect, near treeline,15 cm crown) with a cornice break. The region received less snow in the last 24 hours than was forecasted but wind slabs are still worth keeping in mind for Saturday.
Use your evaluation skills to determine which slopes have become wind loaded and monitor the depth of wind deposited snow. As wind slabs become deeper, avalanches can become larger. Wind slabs typically form below ridge tops, high points, and other features that catch wind transported snow. You can also find 'cross loaded' slopes where wind wraps around features. Signs of unstable snow such as recent avalanches and cracking in the surface slab are good indicators that you can trigger an avalanche.
Isolated terrain features may accumulate enough wind blown snow to produce large avalanches, especially at the higher elevations.
Areas with sparse or dead trees can be subject to wind blowing snow. Watch for signs of wind slabs forming in these areas that you would typically think of as 'below treeline'.
(4/26/2024)
Intentional cornice break triggered a small wind slab avalanche (east aspect near treeline). This was a small avalanche, but it is a good indicator that wind slabs are out there. The cornice was hanging about 3 feet out and broke easily.
Photo: Aaron Hartz