Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2
The main places where you could trigger an avalanche are upper elevation slopes loaded by snow blown by strong east winds early this week. Look for signs of wind-blow snow which added some weight and stress to buried weak layers, and avoid these slopes.
A generally dry winter so far has dramatically weakened the snowpack which is weak, rotten, sugary and faceted. In many places the entire snowpack is sugary and faceted and lacks a slab on top of this persistent weak layer to produce an avalanche. At higher elevations where the snowpack is deeper, the bottom 1/3 to 1/2 of the snowpack is facets with a slab on top that could produce an avalanche. In some places there are two distinct weak layers, one closer to the ground and one about a foot deep as JG found two days ago and described in his great observation.
Looking ahead - The approaching storm will create dangerous avalanche conditions. What's especially scary this weekend is that you won't have to ride on a steep slope to trigger an avalanche. Just going near or under a steep slope will be enough to trigger an avalanche that comes crashing down.