Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 1–1.5
What and where is it: Today, you have two types of wind slabs to keep in mind:
Old wind slabs have been observed in highly sheltered east-facing terrain at mid-elevation. These are small and highly isolated and may be found in areas like the Summer Lion Head Traverse or under the ice bulge in Main Gully in Gulf of Slides.
New wind slabs could form in north, northeast, and east-facing terrain at middle and upper elevations from new snow and decreasing southwest winds.How can you recognize it: Old wind slabs have been easy to identify from the slick 12/29 melt-freeze crust as bright white, rounded, and pillowy, softer snow. They have also been observed to have strong-over-weak structure.
New wind slabs could form as small, soft, reactive slabs. Look for blowing snow at ridgelines, thin areas of bright white new snow, and new drifts forming to identify this problem.
How can you manage it: Visually inspect terrain to plan your route as you travel on steep north and east-facing slopes. Look for sheltered terrain that has smooth white snow as potential areas of concern for old wind slabs. For newly forming wind slabs, assess the size and sensitivity using poles, probes, or boot penetration, and dig down to the 12/29 melt-freeze crust to assess sensitivity. Both wind slab problems are expected to be small; however, a small avalanche could lead to a fall that is impossible to stop. This could be consequential if it leads to exposed rocks, trees, or cliffs.
(12/31/2025) Turn around point around 4400’ Photo: Ryan S
Gulf of Slides Main Gully underneath the ice bulge- an observation of an isolated small wind slab with strong-over-weak structure