Southern San Juan
AvalancheJeff Welch · Feb 12, 2023 · Southern San Juan
Weather
Weather on Saturday afternoon was overcast with thin, high clouds and warm temperatures. Winds were moderate and gusty above treeline - difficult to tell direction due to local terrain features I traveled in. Sunday was warmer, with thinner high clouds, and calm winds.
Snowpack
I did not dig. Ski penetration on all aspects traveled was less than about 10cm and boot pen less than boot top. Supportable snow everywhere I traveled. Sufaces on shady aspects below treeline were generally faceted and not cohesive. More open areas near treeline on these aspects had wind effected snow, ranged from rippled soft snow to stout crusts. Below these wind effected surfaces were small facets. Not concerning now, but might be after the new snow this week. West aspects below treeline had a zipper suncrust small open areas, soft snow in protected areas, and wind scoured in open fields. Southeast and east aspects near treeline appeared to have a stout suncrust. I did not travel in the alpine, but conditions appeared to be a mixed bag of wind effected, scoured, and sun effected snow. Also observed a large roller ball on a NE aspect below treeline that had run in the previous days.
Avalanche
Observed one old persistent slab avalanche in Owen Basin off Jackson Ridge. Based on newer snow obscuring crown and debris I'd estimate it to be at least 2 weeks old. Ran in very steep N/NE facing terrain below treeline, with a crown line several hundred feet wide and approx 3ft deep. Estimated size R3D2 and ran approx 200-300 vertical feet. Assumed to be natural based on location.