Northern San Juan

Avalanche

Chris Dickson · Feb 1, 2023 · Northern San Juan

Weather

Cold and clear day with very calm winds. Despite strong solar input, the surface of the snowpack stayed cool. Temps likely rose into the high teens/low 20's at the peak of the day.

Snowpack

Above 12,000', there was 4" of low density snow atop a variable wind slab. In some places (ridges, high points in the terrain) the windboard underneath was 5" thick and impenetrable. In other areas (gullies, low points, planar slopes) the windboard was 1-2" thick and breakable, or just a windskin. These windslabs more or less disappeared once we descended below treeline. Dug a pit on a NE aspect at 12,000'. Height of snow was 170cms. Below the 1F-hard windslab, the snowpack was mostly right side up, until you 4F and F-hard facets 140cms down. Below the facets lurks a 15cm thick layer of well developed 3-4mm depth hoar. A shovel shear revealed numerous planar interfaces in the upper pack, but no propagation in our ECT.

Avalanche

Several D1 point releases on steep southerlies (likely from 1/31).