Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
You are most likely to trigger an avalanche on drifted northerly and easterly slopes at upper elevations. The wind will continue to drift recent snow into cohesive slabs over buried weak layers two to three feet deep. The avalanche you trigger in the surface snow could be large enough to bury you. If you trigger an avalanche at the surface, it can easily step down to buried weak layers, growing larger and wider. Multiple sets of tracks on a slope do not mean it is safe. Parties report the second, third, and even fourth person on a slope triggering a slide. Cracking or collapsing in the new snow is a sign of instability, but you may not see any before you trigger an avalanche. Look for safer riding on slopes sheltered from the wind without a surface slab or on lower-angle slopes.