Northern San Juan
Avalanchewilliam marsh · Mar 8, 2021 · Northern San Juan
Weather
Broken skies and strong winds aloft. Winds were intermittent BTL and snow flakes occasional with only a trace of accumulation. Cloud cover and winds kept snow surfaces from warming and a stout supportable sun crust dominated most slopes except due North. Yesterday temps were hot and winds were calm which was the likely trigger for this avalanche.
Snowpack
Melt freeze crust is likely bed surface. Avalanche probably started with the new snow load from 3/3-3/4, 1-2 feet deep with wind loading. Intense direct solar gain warmed most slopes on 3/7 (especially on the S side of the compass) deep into the pack. Several other Wet Slab avalanches in the NSJ zone were noted from 3/7 already though smaller in size.
Avalanche
Several small wet loose avalanches are visible in the upper southerly terrain above the town of Ophir. This appears to be a Wet Slab release with a large crown approximately 600 ft wide and running 1500 ft vertical, well short of the Ophir Pass road. D3, very large debris pile fanning out 800 ft wide.