Southern San Juan

Avalanche

Chris Bilbrey · Jan 17, 2023 · Southern San Juan

Weather

Bands of heavy snow and strong southwest wind during the afternoon. Evidence of drifting well below the treeline to around 9,000 feet - in the form of wind swells in open areas and thick, denser drifts.

Snowpack

We didn't have to travel far off the main road to find evidence of instability. Snowfall that fell over the last 12 hours was denser and/ or more wind-thickened than snow that fell overnight Sunday. This created an upside-down storm slab on the surface which readily cracked along the skin track. These conditions also made for arduous trail-breaking. Throughout our limited travels, we found around 12 inches of 1F- snow sitting over F-hard snow. In a snowpit dug on a south-facing slope at 9,300 feet, we observed propagating failures in Extended Column Test at 7 and 10 taps down 30 cm and 60 cm respectively. Both of these failures occurred in F-hard storm layers.

Avalanche

Noticed several Storm Slab avalanches that failed on east and west-facing slopes just above the canyon floor. None looked as if they broke deeper than snowfall starting Saturday night. We had no visibility into higher, bigger terrain.