Storm Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1.5–2.5
Large and potentially dangerous slabs of new snow will build throughout the day as new snow accumulates - over a foot may stack up by this afternoon near treeline on Mount Shasta. The deepest slabs will form where strong southerly winds deposit snow on west through north through east aspects, especially below ridgelines and in gully features. Avalanches may fail at the new/old snow interface or on density changes within the storm snow.
Natural avalanches are possible, especially in steep (>35 degrees), wind-drifted terrain near and above treeline. Consider avoiding travel on or underneath these slopes.
Human-triggered avalanches are likely. Carefully evaluate the snowpack and monitor new snow totals as you move through the backcountry. Watch for red flags like blowing snow and cracking to alert you to instability. Stick to mellow, sheltered slopes for better visibility and to reduce your avalanche exposure - but watch out for shallowly buried rocks, trees, and stumps, which are everywhere under the new snow. Ski and ride with caution.
(2/17/2026)
Watch for signs of instability, like shooting cracks, as you move through the backcountry.
Photo from a February storm - Human-triggered shooting crack and small storm slab on Gray Butte.
Photo: Christian Jordan