Northern San Juan

Avalanche

Mike Barney · Feb 18, 2021 · Northern San Juan

Weather

Calm, cold day, with few clouds, and no blowing snow observed.

Snowpack

I found 60cm of snow on south facing terrain at 10,000'. About 40 cm of new snow that fell this week. It was moist on the surface midday and had a zipper crust in the afternoon. The snow depth in a flat area at the top of the ridge (11,654') was 160cm deep in an area with little wind affect. At 11,587' on a northwest aspect with a total snow depth of 145cm there was 55cm of fist to 4 finger new snow, sitting on top of a 1 finger hard midpack, resting on 62cm of weak 4 finger hard faceted snow from December. This seemingly poor structure produced no propagating results in extended column test and hard compression test results. A few collapses were observed at around 10400' on southeast facing terrain otherwise no other cracking or collapsing was seen.

Avalanche

The Lizard Head Pass area had a widespread avalanche cycle on 1/16 on all aspects and mostly near and above treeline. These avalanches were large to very large(D2 to D3) and ran during or right after the storm ended on the 16th. There was a large natural avalanche that ran around the 16th in sunshine bowl on a west aspect above tree line and was one of hundreds of large natural avalanches that ran on all aspects this week in the Northern San Juan Mountains.