Northern San Juan
AvalancheColin Mitchell Aaron Ball · Dec 14, 2018 · Northern San Juan
Weather
Pleasant day, with warm temperatures and little wind. High thin clouds covered most of the sky with plenty of sun getting through.
Snowpack
Northeast aspects near treeline are still producing propagating results with tests, as well as propagating collapses. We experienced several of these collapses, accompanied by shooting cracks. Two were large enough to have produced D2 avalanches with more slope angle. We found two potential failure planes on NE aspects, facets at the ground, and another layer around 50 cm down (see profile for details). This is the layer that propagated in the snowpack tests, and also the likely failure layer in the collapses. SE aspects had the expected hard windslabs near ridges, and we also experienced collapsing and shooting cracks when we crossed these slabs. Failure layer was basal facets. Snowpack structure was simple- newly formed slabs over a thin layer of facets and old crusts. Lower down on these slopes we found good skiing and no signs of instability. More slides from our recent avalanche cycle were spotted on NE aspects.
Avalanche
More avalanches from Tuesday night's natural cycle were spotted in Cement Creek on E-NE aspects. All were large persistent slabs.