Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
You will find a fragile base to the snowpack on northerly and easterly aspects from the early seasonal snowfall back in October. Over the past week, up to 2 feet of snow has fallen on top of these Persistent Weak Layers. Observations from Saturday included natural avalanches, collapses, shooting cracks, remotely-triggered avalanches, and an unintentional skier-triggered avalanche. The evidence seems pretty clear that triggered avalanches are likely on Sunday. The danger will drop slowly in the coming days. The problem is best managed through a conservative slope angle. One potential exception to the distribution rose above might be found on high elevations southerly slopes. Sunny slopes at upper elevations developed thin, continuous coverage in some areas just prior to this past week's snowfall. Take a very cautious approach and investigate the snowpack on steep southerly slopes at upper elevations prior to descent.
This avalanche was remotely triggered from 600 feet away and grew large enough to bury or injure a person. North-facing terrain at Paradise Divide. 11/25
Photo: Ben Pritchett