Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
You could trigger a large avalanche that breaks deeper in the snowpack where previous winds stiffened snow into cohesive slabs on slopes steeper than about 35 degrees. The most dangerous slopes face west through north to east, where very weak snow lurks beneath more recent snow. Recent westerly and northerly winds also drifted snow onto leeward slopes, building small slabs of wind-drifted snow near ridgelines and on the edges of gullies. Avoid steep slopes if you see cracking in recently drifted snow.
You can reduce your chances of triggering an avalanche by traveling on simple terrain and avoiding common trigger points, such as convex rollovers, rocky outcrops, or the edges of slopes where the margins of a slab are the thinnest. Give yourself a wide buffer from suspect slopes steeper than around 35 degrees. You may not experience obvious signs of instability before triggering a dangerous avalanche.