General Observations

Keystone Canyon: Approximately 15cm of new snow from the 2/11-2/12 storm was being transported by 30-40mph outflow north winds forming deep drifts and soft slab potential. Areas of concern appear to be wind loaded and cross loaded features, unsupported snow slopes, and low-density alder patches. This new snow is sitting on the 2/8/20 upside-down storm cycle that ended warm creating 4F to 1F over F, with those layers varying in thickness and depth depending on the elevation from the river to the canyon rim. Basal layers and mid-pack are composed of facets and decomposing crusts. We triggered a D1 soft slab avalanche in the Simple Twist gully/apron with a 30cm crown which was large enough to sweep a person down the slope, the avalanche bed surface was the 2/8/20 1F crust layer.