Southern San Juan
AvalancheMatt Huber · Dec 10, 2021 · Southern San Juan
Weather
Strong southwest winds and blowing snow limited visibility for most of the trip. Temperatures dropped throughout the day reaching single digits by mid afternoon. About an inch of new snow accumulated during the trip.
Snowpack
The skin track up is mainly on southerly-facing terrain that was bare ground prior to this last week. About two to three feet covers this terrain now, with no signs of instability seen on slopes that were previously bare. One large collapse on the north-facing slopes above Gibbs Creek produced shooting cracks that failed at the new/old snow interface about a meter down from the surface on well-developed depth hoar. This collapse released an avalanche in steep, rocky terrain roughly 300 meters away
Avalanche
One large whumpf from the broad ridgeline between Lobo Towers and the southern rim of Gibbs Creek. Shooting cracks were seen traveling across the subtle terrain features to the steep, north-facing terrain in Gibbs creek, producing a large avalanche. Visibilty was limited but the crown was between 50-100 cm in depth, failing at the depth hoar. Debris traveled to the valley.