Storm Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
New snow and wind are forming storm slabs. These slabs will be thicker at upper elevations, where snow totals and wind speeds are greater. Anticipate thicker slabs on the northern half of the compass as the strongest winds blew from the SW-S-SE. Slabs formed over various potentially weak surfaces, including facets and crust + facet combinations. Expect freshly formed slabs to be easy to trigger on steep slopes. Some may be triggered by lower-angled terrain above, below, or to the side of a steep slope. The likelihood of triggering one of these sides will increase where you find a thicker, stiffer slab of snow—most likely near ridgelines and exposed terrain features.
New snow alone isn't a problem, but rapid settlement, wind stiffening, or drifting can quickly change the equation. Look for signs of wind loading, like fresh cornice growth and dunes or ripples in the snow surface. Feel for stiffer snow and watch for obvious signs of instability, like snowpack cracking or collapsing. You can always reduce your risk by sticking to lower-angled terrain and avoiding slopes that end in terrain traps like cliffs, trees, or creek bottoms.
(3/13/2025)
Remotely triggered storm slab on Paymaster Peak at 9200' NW aspect. This was triggered from ~100' feet away on a ridgeline.
Photo: Sawtooth Avalanche Center