Southern San Juan
AvalancheChris Bilbrey · Feb 18, 2021 · Southern San Juan
Weather
Beautiful sunny day in the mountains. Light northwest wind with moderate gust along ridge tops.
Snowpack
The upper snowpack above weak, faceted snow below treeline has gotten deep recently and signs of unstable snow were non-existent in our travels. Plenty of evidence exist that the snowpack as a whole is being tested by our recent load. At lower elevations, the most suspect slopes are those with a faceted crust below recent snowfall or sandwiched between prior storms. We observed easy propagating test results on a west aspect with 13 taps above a faceted crust. Just on the other side of the ridge and on north-facing below treeline slopes, ECTs only produced non-propagating results in a layer of 3-5 mm facets below January and February snowfall. Triggering a slide in this deeply buried weak layer seems more difficult, but the ensuing slide would be unsurvivable. Storm snow instabilities appear to be settling out and we didn't observe any loose sluffing in steeper, but heavily treed north-facing terrain. With the abundance of new snow, we still avoided steep, open areas below treeline.
Avalanche
Observed evidence of numerous slides that ran naturally during our last storm cycle. Most of the crown's were filled in but still identifiable. Debris had a small amount of snow over top suggesting that they ran between 2/13-16.