Northern San Juan
AvalancheJeff Davis · Dec 3, 2016 · Northern San Juan
Weather
Beautiful cold, crisp, and clear day.
Snowpack
HS ranged from 20cm below treeline in protected areas to 140cm in the alpine in wind-loaded pockets. The snowpack below treeline is thin and weak, as in many areas boot-penetration is all the way to ground. The snowpack gains depth and the mid-pack slab gains strength as you move higher into the alpine. Facets continue to persist at the bottom of the snowpack on most slopes. The slab facet interface, with a layer of firm snow over a layer of sugar snow, was observed in almost all of my hand-pits and pole-pits. The one place I did not find facets was on an east-facing slope above treeline in a wind-loaded pocket just below a ridgeline. (See below photo) This area had a deep snowpack and most likely did not have any snow on this particular piece of terrain prior to last weeks storm.
Avalanche
On a north-facing slope above treeline a skier in the party heard an audible collapse and witnessed cracking in the snow. See attached photo Multiple Loose-Dry avalanche debris piles observed below cliff-bands and rocky terrain. They look to have run yesterday.