Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
Dangerous avalanche conditions exist. You can trigger an avalanche where you find a cohesive slab of new or drifted snow on slopes steeper than around 30 degrees. Avalanches triggered in the new snow may gouge down into older weak snow and become large enough to bury you. The most dangerous slopes tilt towards the north where the new snow forms a cohesive slab over weak older snow. Look for and avoid areas of wind-drifted snow above treeline, especially on leeward slopes below ridgetops and in cross-loaded gullies.
If you experience cracking or collapsing in the new snow, give steep open slopes a wide berth, because there is a chance avalanches could be triggered for a distance or from below. Even triggering an avalanche on a small slope could be dangerous if it sweeps you into a terrain trap like a gully, creek, or rocks and trees. Avalanche conditions are the most dangerous we’ve seen in a month.