Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
In the last week there have been numerous hard slab avalanches that have failed on weak snow formed in January. This weak layer exists above 8,000 feet on slopes that face west through north through east. These are hard slab avalanches, breaking 2 to 3 feet deep, that can be triggered by the weight of a rider, or from a distance, so give steep terrain a wide berth. Even smaller slopes around creeks and in the trees can produce avalanches if they are steep. As we move farther away from the last loading event, signs of instability such as cracking or collapsing may not be present, but consequences are still high. Avoidance is the best way to deal with this problem as persistent slab avalanches are not manageable.
Watch for pockets of unstable snow in the higher peaks where shallow wind slabs may have formed. A small avalanche failing near the surface has the potential to step down into buried weak layers, becoming large and unmanageable. Also, solar gain and warm temperatures could create shallow wet snow avalanches on steep southerly slopes. Take this into account in your travels today.
(2/27/2026)
Recent avalanche near Split Rock yesterday. This avalanche was on the smaller side, but if piled up in a creek of depression it could still bury a rider.