Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 2–2.5
A weak layer of sugary snow, often associated with a thin crust, continues to be well documented 2-4ft below the surface. The further we get from the original storm, the less likely these avalanches become, but they are not impossible.
You’re most likely to trigger a persistent slab in areas where the snowpack is thin (wind stripped or near rocks), in complex terrain with steep rollovers, or on unsupported slopes. Given the current depth, large triggers like groups of people, cliff drops, or small wind slab avalanches could be needed to cause this layer to fail.
No recent human triggered avalanches have been reported despite lots of weekend backcountry use. However, a collection of large crowns was spotted on Sunday just a few miles from the main Baker Backcountry core. What does all this mean? Persistent slabs are hard to predict, especially this far from the storm. Stack the odds in your favor by avoiding complex, higher consequence terrain.
(2/9/2025)
This slew of natural avalanches in the West Fork of Swift Creek were reported on Sunday. The time of occurrence and weak layer are hard to pin down. Whatever the details, it's proof the layering is still out there to produce slab avalanches. North aspect at 5500'.
Photo: Andrew Richardson