Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2
A slab of cohesive snow now exists above a persistent weak layer of faceted snow on all aspects. This weak layer formed during the December dry spell. Near treeline and above, elevated winds have stiffened the snow and produced slabs of wind drifted snow over top of this weak layer. The layer is most widespread on slopes facing W-N-E, where winds have built thicker slabs on top, but it's also becoming reactive on southerly aspects. The bottom line is that we are developing one of the more treacherous snowpacks I've seen in a long time, with a widespread persistent weak layer, and incremental loading exacerbated by the wind. We're going to need to tread lightly and avoid avalanche terrain for some time.
The video below is of an extended column test performed on a SW aspect on Sunday, January 14.