Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
You can easily trigger an avalanche on steep slopes above treeline. The most dangerous areas are where winds formed stiffer and deeper slabs at upper elevations. These areas of wind-drifted snow are found below ridgelines, in gullies, and in cross-loaded terrain. A wind direction change will cross-load east-facing slopes making these areas the most dangerous. Look for cracking or collapsing in the new snow as a sign to move to lower-angled slopes.
Warm temperatures will increase the likelihood of loose avalanches at lower elevations. If the snow feels sticky, glops to your equipment, or you see pinwheeled snow move to a shaded or lower-angled slope.
You can find safer travel options by sticking to slopes less than about 30 degrees in steepness or by choosing wind-sheltered lower-elevation slopes.