Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
You will find a fragile base to the snowpack on northerly and easterly aspects from the early seasonal snowfall that accumulated back in October. Over the past week, up to 1.5 feet of snow has fallen on top of these Persistent Weak Layers. This past weekend, the neighboring NW Mountain Forecast Area had a notable natural avalanche cycle and several close calls with human-triggered avalanches. We observed a few natural avalanches in the SE Mountain Forecast Area, however, we lack much data given the shallow snow depths and difficult conditions for winter travel. The most suspect areas for this avalanche problem will be on previously wind-loaded northerly and easterly facing slopes and where the total snowpack is near or above 2.5ft on the same aspects. Obvious warning signs will include shooting cracks, a collapsing snowpack, or past avalanche activity.
This persistent slab avalanche was remotely triggered from below in the NW Mountain Forecast Area. 11/26