Persistent Slabs
- Alpin
- Limite forestière
- Sous la limite forestière
- Probabilité
- Possible
- Taille
- 1–2
You can trigger an avalanche which breaks on weak layers in the middle or bottom of the snowpack. The most problematic areas are near and above-treeline slopes facing north though east to southeast, where wind-drifted snow forms a stiff slab above weaker layers below. Look for and avoid slopes with evidence of wind-drifting, such as stiff or sculpted surface texture, drumlike or hollow-sounding snow, fresh cornice growth, or lens-like pillows. Bright sun and rapidly warming temperatures will also create increasing danger from loose wet slides on lower-elevation sunny slopes as the day progresses, so plan your exit, and retreat if you see roller balls or sink in past your ankles. Slopes less than about thirty degrees without steep terrain above offer safer options.