Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
In wind-loaded areas, avalanches could be dangerously large and may break widely across terrain features or be triggered from a distance. Look for recent avalanches, textured snow, and thick, pillow-like drifts that highlight slopes of concern. Keep your distance from these features and stay well clear of cornices.
A major westerly wind event that stressed weak layers, warm temperatures, and sunny skies is prolonging the instability. In the past week, observers have reported collapses, long cracks, and propagating test results. Weak layers (facets and surface hoar) adjacent to crusts are 1-1.5 feet deep, widespread on a variety of slopes, and have been the source of multiple avalanches.
(2/22/2026)
A small, remotely triggered avalanche in the Buillon Basin area, failing 14-16" deep on buried surface hoar.
Photo: Sam Clairmont