Southern San Juan
SnowpackChris Bilbrey · Nov 7, 2022 · Southern San Juan
Weather
Mild sunny day with a moderate south wind.
Snowpack
The snowpack on upper elevation, northerly-facing slopes consists of two layers: weak faceted snow from October lurking below last weekend's snowfall. The hardness of weak faceted snow ranged from F to 4F-, was mostly 1-3 mm in size, and was around 8 inches thick near treeline, but up to a foot thick in the alpine. Last weekend's storm delivered around 2 feet of snow in this portion of the La Plata Mountains, and the overlying slab has since settled into a 4F to 1F hardness slab (top to bottom) around 14 inches thick. After collapsing a heavily wind-drifted pocket of snow in the alpine, our Extended Column Test adjacent to the collapse propagated a failure across the column with 10 taps. While a lot of discontinuity exists across many northerly snow-covered slopes, the one consistent finding was slopes that harbored enough snow to slide on had a uniform stiff over soft snowpack structure throughout. East-facing slopes have a similar snowpack structure, but facets at the ground are moist and slightly harder, and hold-over snow from October was more sparse. Below treeline areas are still the shallowest, and we suspect that only very steep, isolated areas seem to be where you could provoke a smaller slide due to the number of obstacles poking through the snow surface.