Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
A recently buried weak layer is proving untrustworthy. Reports of remotely triggered avalanches, shooting cracks, and audible collapses continue to trickle in each day. Expect to encounter similar signs in areas where 6 or more inches of recent snow fell, or where winds drifted snow into thicker slabs. These conditions will be most commonly found in the central and northern Whitefish Range, where more snow fell.
You can identify the weak layer by visualizing a grey strip in the upper snowpack, or by locating the uppermost crust. It will vary from place to place. Wind-loaded areas will be the most dangerous, since that is where slabs are thicker and harder. Seek out terrain sheltered from west and southwest winds. If you observe signs of unstable snow (shooting cracks, whumpfs, or triggered avalanches), resort to lower-angle slopes for a safe riding experience.
(1/31/2026)
This avalanche was triggered by snowmobiler in the northern Whitefish Range. We assume this avalanche failed on a buried persistent weak layer.