Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 3
Last week's storm cycle has settled into a dense, slab 8"-12" thick on top of the Feb 11, faceted weak layer. On west facing slopes near and above treeline, and on low elevation, northerly aspects, human triggered, avalanches failing on this weak layer are possible. The danger is much more acute on steep, northerly aspects, near and above treeline, where hard slabs 2 to 4 feet thick now rest above this weak, faceted layer. Human-triggered avalanches failing on the 2/11 layer remain likely, and once triggered, may step down deeper into the snowpack resulting in much more destructive and deadly avalanches.
It's been a week since the last storm and natural avalanche cycle, and obvious red flag signs of instability such as collapsing and cracking are no longer evident. But make no mistake, many steep slopes that did not avalanche during Friday’s storm remain primed for release. The safest strategy is to continue to avoid slopes steeper than 30 degrees.
