Northern San Juan
AvalancheJeff Davis · Nov 11, 2018 · Northern San Juan
Weather
Clouds and wind built during the day from the west. Light snow showers (S-1) were observed starting around 1pm.
Snowpack
A mix of slabs and facets persist throughout the snowpack above treeline. The snowpack differs in depth widely depending on how much snow has been loaded onto a slope and the amount of sun that slope receives each day. The deepest and most dangerous slopes face north and are wind-loaded. The surface snow was near-surface facets on some slopes and a slab on others. The snow above the ground was a moist 4 finger facet layer. Recent cold and clear nights have accelerated the faceting process. One large avalanche was triggered on a cross-loaded north facing slope. No other cracking or collapsing observed.
Avalanche
A large Persistent Slab avalanche was triggered on a north facing slope above treeline. The avalanche was triggered by the third skier on the slope on there fourth or fifth turn. The depth of the crown ranged from 100-20 cm and propagated across the cross-loaded terrain feature. The max depth of the debris was around 200-250 cm's. The avalanche ran approximately 275 meters. The skier was not caught in the avalanche.