Southern San Juan
AvalancheChris Bilbrey · Feb 11, 2023 · Southern San Juan
Weather
Chilly morning temperatures under clear skies. High thin clouds moved overhead late morning and wind speeds increased out of the south reducing today's warm-up. This kept wet snow concerns at bay across all elevations. No visible snow transport in the alpine.
Snowpack
We found 2 to 3 inches of snow from the 2/8-9 storm around 11,000 feet up to the treeline. In the alpine, lots of wind effect left little to no evidence of the fresh snow. Surface faceting ranged from 4 to 8 inches depending on aspect and elevation and was more advanced in the alpine than we had expected. Below the treeline, surface weakening more pronounced on northerly slopes and east through south to west-facing slopes is crusting over. We encountered variable surface conditions at upper elevations from strong northerly winds this week. Some places harbored soft, textured surfaces consisting of a pile of faceted snow next to a breakable wind skin above weak faceted snow adjacent to a very stout wind-board (2 to 3 inches thick) with weak faceted snow below and the classic trap door setup. Once isolated, the firm wind-board would easily fail in test with easy force and where this harder layering was absent, the faceted snow would progressively collapse under the shovel. Weak layers down one to two feet below the surface were mostly unreactive in test. Our snowpit on an east-northeast aspect just above the treeline yielded a total snow depth of 150 cm and November facets were around 115 to 125 cm below. While these depths were unexpectedly shallow for the location and elevation, the main body of the snowpack is just as stout as other places we've traveled lately. The well advertised warm-up did not drive wet snow concerns today and the lack of more recent snowfall below the treeline and many warm, sunny days this month are likely to keep wet snow concerns on the backburner for now.
Avalanche
Lots of evidence of larger natural avalanche activity from January cycles. Several small Wind Slab avalanches had occurred in high-elevation couloirs and below steep cliffs in the last week or so. None grew larger than a size 1 or traveled very far.