Northern San Juan
AvalancheDevin Overton · Mar 25, 2021 · Northern San Juan
Weather
SW wind sustained in the low 20s gusting into high 30s near 12,500 feet. Clear evidence of substantial snow transport from overnight and morning wind. Obscured vision in the alpine by 10:00 am due to lowering cloud ceiling and increasing snowfall. Miserably cold wind chill values.
Snowpack
Roughly 12” of new snowfall over previous two days combined with heavy SW wind above treeline. Clear evidence of new wind slab formation and cornice growth on north through east facing slopes on leeward side of ridge.
Avalanche
Fresh natural persistent slab avalanche in the “Gemini” bowl. Poor visibility made investigation of the slide’s cause and dimensions difficult to see. Likely cause of slide would be from cornice release above, which then stepped down to the persistent weak layer at ground level. Crown width was difficult to determine, but likely 150-200feet wide. Crown height was estimated at 6-8 feet, with rocks and grass apparent on the bed surface. More than enough obvious red flags to happily ski the mellow skin track to Trout Lake :) (Unfortunately no images)