Southern San Juan
SnowpackChris Bilbrey · Nov 8, 2022 · Southern San Juan
Weather
A mild day with breezy conditions along ridgetops.
Snowpack
The snowpack structure observed on northelry slopes in the Wolf Creek Pass area is similar to other parts of the San Juan Mountains - a thick, cohesive slab sitting above weak faceted snow. Total snow depth near treeline ranged from 50 to 70 cm's, and 15 to 20 cm's of faceted grains at the ground. Despite the lack of cracking and collapsing on our travels, our Extended Column Test consistently produced propagating failures with about 13 taps, and Compression Test yielded sudden planar results. In a snowpit on a northeast-facing slope, we found a 5 cm crust buried in between weak facets at the ground and recent snowfall. This harder layer could allow the overlying slab to support a larger new load before a failure occurs. This buried crust layer was absent on northwest and north-facing slopes at similar elevations. Below treeline, facets at the ground are moist, harder, and half the depth as upper elevations. The snow surface has weakened and become more unconsolidated from recent warm days and cold nights. Not isolated to surface faceting, we also observed faceting below a firm melt-freeze crust on east through south to west-facing slopes, and below wind-stiffened snow in wind-exposed areas. While surface faceting did not drive a change in the hazard today, it could quickly become our next weak layer to contend with from additional snowfall this week.