Southern San Juan
AvalancheAnonymous · Apr 4, 2020 · Southern San Juan
Weather
On the East facing Ridge at 11,000 feet, it was partly cloudy, occasional strong sun, temperatures rising to the mid to upper 30's depending on sun coming out or being obscured. Light to moderate wind from South.
Snowpack
Frozen crust at surface softening throughout day in sun-exposed areas. While ascending East facing ridge at 11,000 ft, softness was increasing but not quite boot top penetration. Probing with pole while skinning up this ridge, I suddenly punched into a layer of softer facets about 1.5 - 2 feet deep right around 11,000 feet as I was coming to the bench. Prior pole probing yielded a shallower snowpack that had melt-freeze to the ground. Following the avalanche, we did not dig a pit and did not deem it safe to venture out and examine the crown and bed surface.
Avalanche
Just as I reached the bench below the rock outcrop at 11,000 feet, I heard a loud whoomf and turned to see a fracture break behind me and to my left about 30-40' down from the ridge. The avalanche broke about 200' wide and 8"-20" deep and wrapped around multiple terrain features to more southeast facing terrain ahead of me and to my right. It appeared to break on a convexity near a small stand of trees where the slope was steeper and faced NE. The crown here was a visually estimated 20" deep. The rest of the slope faced East-Southeast and the crown was shallower. The debris fanned out roughly 300 feet wide on a bench at the bottom of the steep slope at 10,700 feet. The slope that failed was about 40 degrees and already had 2 sets of ski tracks on it from the ridgeline just above 11,000 feet.