Avalanche: Summit

Amazing partly sunny spring day, 38 F when we started at 11:30, temps reached 41 F in the afternoon for several hours at the Summit Creek snotel. There were some high clouds that were in and out throughout the day.

The shaded surfaces were frozen with a 3” crust at the parking lot with moist snow underneath. At 2,000’ facing southwest there was a 3” crust that was starting to soften. At 2,500’ facing west the crust was 2” thick. There was dry settled powder on the north facing slopes at 3,500’ and there was widespread surface hoar everywhere. In the lower elevations it was melting with the sun effect.

We dug several hand pits along our tour. The first at 2,000’ was the most concerning with an easy failure 5” down on what I think might have been surface hoar, but I wasn’t sure. It also failed simultaneously about 1’ down on a thick layer of facets, the slab was 1F and the facets were F+. Hand pits at 2,500' and 3,200' facing west had moderate failures 1' down on a hardness change, and a hand pit at 3,600' north aspect had a hard uneven failure 1' down on an unknown layer.

We dug a snowpit at 3,600’ on an east aspect 18 degree slope. We did not get any concerning results in the tests (CT11 down 5cm under a crust, ECTX). We did find the set up for an avalanche with a weak layer of facets below a slab. We will keep an eye on this and it will become more concerning when the snowpack gets an additional load of snow, wind, or warm. Also, a similar structure exists on other aspects E-S-W that get warmed especially on sunny days which adds weight to the slab increasing the avalanche danger the more it warms.