Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2–3
Our main concern continues to revolve around a layer of faceted snow (weak) that is buried around 2' deep. While signs may point towards decreasing sensitivity, the size and distribution of recent natural and human triggered avalanches continue to keep our team concerned about the possibility of large human triggered avalanches today and in the days ahead.
The slab above the weak layer has changed significantly in the last few days. We have gone from a mostly right side up slab consisting of powder snow, to a now top heavy slab with stiffer wind affected snow at the surface. It is difficult to know what this has done to the sensitivity of our persistent slab across the entire region; we do know that the slab has become more cohesive and connected. Weak snow may be more difficult to trigger, but if initiated, avalanches could propagate deeper and wider than expected.
This is a dangerous setup because conditions can feel more “manageable” than they really are, similar to the stubborn wind slab problems we often see on Thompson Pass a couple days after a wind event, while a deeper weak layer still lurks underneath. We recommend users continue to take a cautious approach and keep terrain choices simple today as uncertainty remains high. Maintain good communication with your group and only expose one person at a time to avalanche terrain.
Wind Slab: Recently formed wind slabs will be stubborn to reactive to triggers in specific areas such as cross loaded slopes, gullies, rollovers, and terrain near ridgelines. As stated above the main concern is that a windslab avalanche that is initiated could affect weak snow deeper in the snowpack, making large, dangerous avalanches.
(2/12/2026)
Natural persistent slab avalanche on north Catchers Mitt. Crown width mapped at~.8 miles
Photo: Kyle Sobek