Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Strong winds over the past several days have created thicker stiffer slabs above treeline. The leeward sides of ridges and cross-loaded gullies will have thicker, stiffer slabs on the surface. There are two main weak layers of concern to look out for. One is a layer of basal facets/depth hoar that rests near the ground in shallower snowpacks. The second is a layer of near-surface facets that we've generally found living under a decomposing wind crust that was the old snow/new snow interface prior to last week's storm.
Obvious signs of instability like shooting cracks and loud audible collapses have become less frequent in the last couple of days. Take the time to dig down into the snow to assess whether this poor snowpack structure of strong over weak exists before committing to a slope.
Stiffening slabs near the surface above treeline from strong winds over the last several days, with a mid-pack faceted layer.