Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–1.5
New snow in conjunction with moderate west winds will create the potential for cohesive slabs of drifted snow in lee and cross loaded terrain, primarily above treeline on Mount Shasta. Any avalanches will be small and located where there is a preexisting bed surface. Precipitation amounts today will be less than a quarter inch with the bulk, around half an inch, falling after 4 pm through tomorrow morning. While technically during the forecast period, the overnight snow will be more of a concern for tomorrow. Winds also increase in speed overnight and shift more southwest.
Slabs are most likely on the highlighted aspects, but may form on any due to the strong local orographics of Shasta and irregular loading patterns during strong to extreme winds. This makes it especially important to recognize wind slabs and where they form – Rounded features of locally deeper snow, most typically downwind of ridgelines and other terrain features. Above treeline, the best way to manage the problem is by avoiding the features of concern and sticking to wind scoured areas or lower angle slopes. Signs to watch out for include blowing snow and cracking/collapsing on small test slopes. In our shallow snowpack, the consequences of being caught in even a small slide are high due to the slick bed surfaces and exposed or shallowly buried rocks.