Southern San Juan

Avalanche

Chris Bilbrey · Jan 7, 2022 · Southern San Juan

Weather

Sunny day with the Wolf Creek fog spilling over the higher peaks. Steady southwest winds along ridge tops, but no visible snow moving above treeline.

Snowpack

We targeted northerly-facing terrain to see how the snowpack is adjusting after the prolonged stormy period before the New Year delivering 9+ inches of snow water equivalent. Our findings suggest the snowpack in the Wolf Creek Pass area is deeper and slightly stronger than the rest of the South San Juan. Facets and depth hoar at the ground sit under a 170 to 230 cm slab from below to near treeline respectively. Depth to weaker snow makes it less likely for riders to impact those troublesome grains. However, added weight from a machine could be enough at present to create a different outcome. Alpine slopes harbor the most slope-wide variability in depth and where you are more likely to trigger a slide - steep, rocky areas where snow depths are shallowest. Soft snow lingers on the surface near and below treeline, but with the slightest turn to the east, we encountered a thin melt-freeze crust. Southerly-facing slopes harbor a thicker crust and also softened enough to produce roller balls on slopes over 35 degrees. Open slopes prone to drifting near and above treeline offer a firm wind-board on the surface, but no cracking or collapsing noted. Of note, we observed widespread surface hoar formation on wind-sheltered slopes all the way up to 11,600 feet. While these delicate feathers at the upper limit may get laid down with future winds, this could be something to watch for at lower elevations as future storms build fresh slabs.

Avalanche

Crowns mostly filled in, so size is a best estimate. Slides appear to have run at the tail end of the December storm cycle with most failing in storm layers. The wide propagating slide below treeline seems to have broke deeper due to how much of the crown was still visible today.