Northern San Juan
Avalanchewilliam marsh · Dec 11, 2020 · Northern San Juan
Weather
Cold, Snowing S1 most of the morning. Light winds gusting to moderate at ridge top from the W, SW.
Snowpack
New snow of 12-16 inches on lee and protected aspects above 10,500 and less than a foot below 10,500. Any East or South aspect at all elevations of our tour had a suncrust that the new snow has not bonded well with. Touring up we saw several naturals and had several remote pockets trigger with ski pressure, up to a foot deep and appox 50'x50' small slopes. In more protected areas on the north side of compass the snow landed on older soft snow instead of crust and was not reacting as easily.
Avalanche
Ski pressure at 11'800' on E, NE start zone, 40 degree slope, resulted in predictable small storm slabs that entrain Lots of new snow. The new snow easily picks up speed in Dry Loose fashion on steep slopes. R1D1 with serious D2 consequences in this particular terrain. Avalanche ran 1000' vertical and the debris pile less than 2 ft depth in the toe. Soft Storm Slab.