New Snow

Decreasing Danger

Main problem--the only problem--is the buried, persistent weak layer on upper elevation, shady slopes (northwest, north and northeast facing slopes above about 9,000'. I investigated the large avalanche triggered yesterday remotely by a couple skiers on the north side of Sunset Peak, which is between Alta and Brighton. It was about a quarter mile wide and 3' deep. It failed on about 6 inches of very weak, faceted snow near the ground. The new snow started out with about 6 inches of graupel so I was initially suspicious that all the avalanche activity was on graupel instead of the faceted snow but, alas, it was our old nemesis, as usual. All my columns failed on the facets near the ground, not the graupel. (ECTP-11, Q1) I don't think I have seen such widespread activity before on such a shallow layer of facets near the ground. It's usually more pockety. Pretty amazing that such a widespread propagation could occur on such a thin layer right above the ground. In theory, it should stabilize more quickly than usual with faceted snow since it's right on the ground and the ground is so warm and it's now insulated by 3' of snow, so there's no temperature gradient. I would think it will settle down in just a few days, vs, a couple weeks like in last year's very thin snowpack. In the mean time, avoid upper elevation northwest, north and northeast facing slopes. They are very scary.