Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Possible
- Dimensione
- 2–3
Recent Avalanches: Summit Lake did not get as much precipitation out of the most recent storm, and saw much less natural avalanche activity as a result. We observed a widespread natural avalanche cycle last week, with notable avalanches on Roaring Ridge, Manitoba, Butch, and Ravens Ridge.
The snowpack remains more concerning in the Summit Lake area than the rest of our forecast zones. The main concern is triggering a very large avalanche failing on weak, faceted snow in the bottom half of the snowpack. We've seen multiple avalanche cycles over the past two weeks involving this layer, and people continue to observe large collapses as they travel. This is all bull's-eye data indicating a concerning snowpack setup.
Summit Lake did not receive nearly as much rain as Turnagain Pass or Lost Lake last weekend, which means the snowpack has not gone through as much of a melt-freeze cycle. Pay close attention to surface conditions as you travel — once surface crusts become unsupportable, chances of impacting that deep weak layer are quickly increasing. Keep in mind, these persistent weak layers do not always give warning signs even when conditions are dangerous. The consistent feedback we have been getting is unusual, and a clear warning sign that we need to manage terrain cautiously.
Wind Slabs: There is a small chance you may encounter isolated pockets of unstable wind-drifted snow above 2500'. The winds have been light since yesterday morning, so these should be healing, but they are still important to assess as you travel. Expect to find them in steep, upper elevation terrain near ridgelines, convex rolls, and in loaded gullies.
(2/1/2026)
Two very wide crowns (one in the foreground and one in the background). The foreground is Roaring Ridge, and the background is a sub-peak just west of Twin Peaks.
Photo: Andrew Schauer