Southern San Juan

Avalanche

Mike Barney Chris Bilbrey · Mar 10, 2021 · Southern San Juan

Weather

Cold and windy day. It was 22F with light south west winds and moderate gusts all day. Skies went from overcast to broken and the sun had no affect on the snow as winds and clouds keep surfaces cold.

Snowpack

This storm came with dust and there was 25cm of snow that fell overnight on Molas Pass. We observed what looked like a large a wind slab avalanche above treeline on an east aspect. With a closer look we found near surface facets 33cm (12") down from the surface under a 1cm thick wind board. With this combination of facets under the wind crust we were able to get hard propagating results (ECTP24) in a snowpack test. This is a layer that can take more weight and needs to be watched during this stormy period. The avalanche crown looked to be about 40 to 45cm deep and most likely failed early this morning with strong winds quickly adding snow/weight to a weak layer close to the surface. Traveling near and above treeline some southerly and westerly high points were striped down to the melt-freeze crust and most above treeline north and east facing terrain was slightly punchy from recently wind drifted snow.

Avalanche

We spied two persistent slab avalanche that failed on near surface facets that were 18 to 20 inches down from the surface. These avalanche started in very steep terrain just below a ridgeline in a wind loaded area. With continued snow and wind in the forecast we can expect to see these avalanches grown in size and potentially naturally slide in less steep terrain. One avalanche ran this morning and the other looked like it ran last night.