Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
On Thursday, the sustained westerly winds were moving a lot of snow. Some of the snow snow was blasting into the sky while some of the blowing snow was finding its way onto lee slopes and building wind slabs. New snow on Thursday was minimal with 1-2" falling on the ground by the afternoon, however there was an abundunce of soft snow on the ground available for transport. With these wind conditions, wind slabs can form in unusual places. Use visual clues to identify where wind slabs have formed below ridge tops, peaks, and around features that catch blowing snow from cross slope winds.
Most wind slab avalanches will be small but isolated terrain features can accumulate enough blowing snow to produce large avalanches. Monitor the depth of wind deposited snow. As wind slabs become deeper, resulting avalanches can become larger.
Utilize small test slopes and low angle terrain to monitor the wind slab. Watch for signs of unstable snow such as cracking in the surface snow and previous avalanches. If you have uncertaintly in the snowpack, stick to lower angle options less than 30 degrees steep.
Be aware of clearings and open slopes with sparse trees below treeline where the wind can move enough snow to build wind slabs on lee terrain features.