Northern San Juan

Avalanche

Chris Dickson · Dec 19, 2020 · Northern San Juan

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Weather

Cold and clear day, temperatures in the low 20’s, sunny with increasing clouds in the PM. Sun was strong enough to warm-up and melt surface snow on steep solar aspects. Light winds below treeline, but observed strong winds out of the West blasting the Wilson Group, Blackface, Sheep etc. and lots of moving snow along ridge tops.

Snowpack

Snowpack is still meager and thin below treeline. In deeper areas, cracking and collapsing was observed. Near treeline, HS ranges from 80-100cm, with most of the snowpack comprised of snow from last weekend’s storm (26cms) and what we got on Thursday (14cms). Last weekend’s snow is settling, stiffening, and rounding into a 4F slab, which is still sitting on our problematic persistent weak layer of late-November facets. Tests produced an ECTP10 which failed on the PWL, and sheared cleanly.

Avalanche

Observed a small natural avalanche (W, 11,300’) that most likely ran during the last storm.