Southern San Juan
AvalancheChris Bilbrey · Feb 14, 2019 · Southern San Juan
Weather
Light snowfall (S-1) upon arrival with obscured skies and generally mild temperatures. Around 1030, rate of snowfall increased (S2) for the remainder of our tour. Wind-drifts near treeline were approaching 16 inches deep.
Snowpack
Coat and glove soaking wet...new snow was dense. Cracking observed in wind-drifted areas and storm slabs became reactive toward the end of our tour near treeline. ECTs produced easy force propagating results in storm snow. We evaluated and tested snowpack structure on a slope that slid during the mid-January cycle. 6 to 8 inches of 1 to 2 mm facets above a knife hard bed surface sits under approx. 30 inches of snow since early February. ECTs produced propagating failures in facets on 15 taps. Block collapsed and slid very easily. Test results made us adjust our travel plans and we stuck to lower-angled, tighter trees.
Avalanche
Skier-triggered several shallow storm slab avalanches failing at a density change. All avalanches didn't run far and were extremely predictable.