Northern San Juan
AvalancheColin Mitchell · Dec 25, 2020 · Northern San Juan
Weather
Warm and sunny, light westerly winds.
Snowpack
Below treeline the snowpack consisted of about 50 cm of facets and unconsolidated mixed forms. A crust has formed on southerly aspects and sun-exposed areas. This extended up to at least 12,000 feet. As we moved up into the near-treeline band, the upper layers were a cohesive slab about 30-50 cm thick, with this week's snow on top. We began to experience collapsing when we traveled over the slab. Several medium-size collapses were followed by a large collapse, ~250 feet in diameter on a 28-degree southeast-facing slope at 11,800'. Several cracks cut across the slab. We moved our skin track onto a more southerly aspect and did not have any more collapses.
Avalanche
Two slides on the northeast-facing part of the bowl below pt. 12,429