Northern San Juan
AvalancheJeff Davis · Dec 12, 2020 · Northern San Juan
Weather
A strong winter snow started around 11 am. Southwest winds accompanied the snow loading leeward slopes. Temperatures were in the teens.
Snowpack
4-5 inches of snow feel during the day today. That brings the storm total to around ~15". The new snow is falling on a fragile snow surface of near-surface facets that developed during the two and a half weeks of high pressure before it started snowing on Thursday. The new/old interface has been reactive, but most avalanches have been on the small side due to the lack of slab stiffness in the new snow. Today, I dug on a NE facing slopes at 11,200' (BTL). Compression Test resulted in easy and very easy failures at that new/old interface, but I did not get propagation on Extend Column Tests. I would expect this interface to get more reactive as the surface-slab stiffens due to wind, settlement, and more snow. I chatted with backcountry users in the area and many reported "touchy" conditions and lots of snow moving in near and above treeline.
Avalanche
Second hand report of small skier-triggered avalanche on a steep rocky west facing slope BTL.