Northern San Juan
AvalancheMike Barney · Mar 24, 2021 · Northern San Juan
Weather
Broken skies over Silverton turned overcast by 1pm and light snow started to fall. Winds were clam at the summit and the temperature was 18*F.
Snowpack
East winds this morning distributed shallow firm slabs 5 to 8 inches deep on westerly aspects near and above treeline. We saw local cracking and one small natural wind slab avalanche that failed below a cornice sometime this morning. We didn't trigger a wind slab but avoided slopes that were over 35* below ridgelines on west aspects. We found a 1cm thick melt freeze crust 23cm down from the surface on a northwest aspect at 11,400 feet. This was the most concerning layer in my pit but this layer produced hard column test results and non propagating extended column test results. Facets have not yet developed around this crust layer. The snowpack was 200cm deep but I only dug down 105 cm because I found a thick knife hard layer. Below treeline a supportable crust on all aspects but north held 2 to 3 inches of new snow.
Avalanche
One small wind slab avalanche fail naturally sometime this morning below a cornice. It was a northwest aspect above treeline.