Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Likely
- Größe
- 1–2
Large natural and remotely triggered avalanches failing on buried surface hoar have occurred this week just over the border at Crystal Mountain and Mission Ridge. Other backcountry travelers near Crystal and the Salmon La Sac also reported a handful of collapses and long shooting cracks in two different buried weak layers.
Wind has been, and will continue to be, the driver of this problem. Moderate-strong wind blew through the zone on Wednesday, and speeds are forecasted to increase even more on Thursday. That means you will encounter more terrain that is wind-affected and overloading these weak layers buried within. A change to denser or harder feeling snow underneath your equipment is a good indication that it has been influenced by the wind.
All steep open terrain is suspect with poor snowpack structure. Long shooting cracks, audible collapses, or natural avalanches are key indicators of dangerous avalanche conditions. Avalanches could be triggered from below or next to steep slopes. Small, steep test slopes or convex features can help gauge the reactivity of the upper snowpack. You can dig small hand pits and pull on blocks of snow to see how easily overlaying slabs break free from weak snow underneath. But given snowpack variability, be cautious about extrapolating your results too broadly. Instead, dial it back by seeking out low-angle terrain protected from the wind...if you can...
(2/22/2026)
A small, remotely triggered avalanche in the Buillon Basin area, failing 14-16" deep on buried surface hoar.
Photo: Sam Clairmont