Southern San Juan
AvalancheJason Konigsberg, Chris Bilbrey · Feb 1, 2022 · Southern San Juan
Weather
Snow started around 2 PM, snowing an inch per hour in late afternoon. Moderate ridgetop winds near treeline throughout the day.
Snowpack
Southerly aspects generally have a thick and supportable surface melt-freeze crust. It is unlikely that we will see avalanches breaking deeper than this crust with the incoming storm. All other aspects (west to north through east) have very weak upper snowpack conditions. On north-facing slopes, there is about 10 cm of near surface facets over the slab that formed at the end of the 2021. There was a very thin fragile melt-freeze crust right above this slab with weak facets in between. Even though the surface was weak on north-facing slopes we did not observe sluffing even in steep terrain. East-facing slopes were a different story. We were able to trigger fast-moving sloughs that packed a punch. Of the different aspects we observed, east-facing seems like it will be most troublesome with an incoming load. The facets below a thin melt-freeze crust (about 10 cm) down were better developed than on northerly-facing slopes.
Avalanche
We saw one old avalanche with significant debris from the end of December storm. We also triggered a couple of Loose Dry avalanches, on of which had enough force to potentially knock a person off of their feet.