Northern San Juan
AvalancheColin Mitchell · Dec 2, 2019 · Northern San Juan
Weather
Sunny day with very light winds and warm temperatures. Sky was almost fully covered with high thin clouds amplifying the solar radiation and helping to warm the snowpack.
Snowpack
We have seen good settlement in this area, at least along the highway corridor. Since Saturday morning, Coal Bank HS has dropped 6", around 28%, and Molas 4", around 18%. West Lime recorded similar numbers, 7" and 17%. The snowpack at the Coal Bank study plot is 1f hard rounds top to bottom with a thin melt-freeze crust around 15cm above the ground. The snow surface was getting wet, and a crust will likely form in most areas tonight. I found basically the same structure in Henry Brown, but a thinner snowpack. Some ground was showing through, and lots of rollerballs. This was typical of all but the most northerly facing slopes. These slopes lacked the crust and rollerballs, but the snowpack showed signs of strengthening and rounding. In West Lime, coverage depth varied across the terrain, but averaged around 16" of moist, rounding 4f-1f hard snow. Large-grained (~2mm)rounding facets were still visible in the bottom third of the snowpack, but there was not a pronounced hardness difference from the rounds. Overall, things seem to be settling out well, and lots of melting in the sunny areas. The snowpack is still thin enough to facet, but the warm weather is allowing rounding to dominate for the moment.
Avalanche
No new activity observed