Storm Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
In many locations, recent snowfall rests on a weak layer (facets or surface hoar) and crusts. Warming temperatures and wind may stiffen this snow into a cohesive slab. These features will be thicker, larger, and more dangerous in wind-drifted areas, although they could also be problematic in sheltered terrain. Slides can be triggered remotely from flat terrain above, to the side, and below steep slopes. This looks to have occurred Saturday in the northern Whitefish Range, where a motorized user triggered a small slab avalanche (See adjacent image).
Look and feel for dense surface snow where your skis, board, or machine do not sink in as deeply. Cracks beneath you indicate you have found a slab, while cracks shooting away from you indicate a sensitive slab. This is a near-surface problem, and hand pits are a good way to assess how well the recent snow is bonding to the underlying layer.
Seek out softer snow and low-angle slopes for a safer and more enjoyable experience. You might be more likely to find these conditions on northerly slopes sheltered from the wind.
(1/31/2026) This small soft slab avalanche was triggered by a motorized rider in the northern Whitefish Range on Saturday. This likely failed on the buried weak snow + crust setup. Riders could trigger slides similar to, or larger than, this one today.