Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2
A persistent weak layer of faceted snow that developed during the cold dry period in mid November still exists on W-N-SE aspects. Obvious signs of instability such as collapsing and cracking are not present but a poor snowpack structure, consisting of strong snow over weak snow, still exists. Slopes facing NW-N-E, near treeline and above, are the most suspect. In these areas wind drifted snow has built thick slabs on top of the weak layer. These hard slabs are 1-4' thick and can produce very large, deep, and potentially deadly avalanches. Over time, these weaknesses can heal but it's still early season and for now, keeping your slope angles under 30 degrees is the best strategy for managing terrain on the north side of the compass.