Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
This problem will build through the day as more snow falls. Moderate to strong winds out of the southwest will build wind slabs on lee terrain features primarily on northerly and easterly aspects.
Wind slabs usually form below ridges and high points. The wind wrapping around north and south aspects can cause wind slabs to build across a slope. Use visual clues such as wavy surface texture and pillowy drifits as an indicator of where this problem is present. Previous avalanches and cracking in wind deposited snow are indicators that wind slab avalanches can occur.
Wind can pile up snow many times deeper than the snow dropped by the storm. Monitor the depth of wind deposited snow; as wind slabs become deeper, avalanches can become larger.
With strong winds in the forecast, be cautious in areas that you may typically think of as 'below treeline', especially in clearings and areas of sparse or dead trees. These areas can be exposed to wind blowing snow and wind slabs can develop.
(3/26/2024)
Skier triggered slab avalanche on a wind loaded convex roll on Tuesday. NNE facing slope near treeline in the Santiam Pass area. The crown was 15 - 20 cm (6 - 8"). Size D1 (small).
Photo: Aaron Hartz