Northern San Juan
AvalancheTroy Nordquist Chris Dickson · Jan 8, 2025 · Northern San Juan
Weather
The morning skies were clear with a cold temperature of 5 degrees F at the nearby Goldhill weather station. A little under 3 inches of new low-density snow, winds out of the Northeast were calm, and temperatures warmed to a high of 14 degrees F in the afternoon.
Snowpack
The snowpack here is simple and quite scary in its poor structure. It's composed of 4 layers: new snow since 12/28, sitting on a widespread knife-hard ice crust (the freezing rain event on 12/28), sitting over snow from the Christmas storm, above very weak fist-minus facets to the ground. The Holiday slab (everything that fell since Christmas) sits over the December drought layer, creating a textbook strong over weak snowpack structure and our current Persistent Slab avalanche problem. The most interesting piece of the puzzle is the 12/28 ice crust, which is unusual for our dry continental snowpack. It was hard to tell if the rumbling collapses were happening underneath this crust, or at the 12/25 weak layer. The ice crust in this area is 3mm thick and the grains under this crust are faceting.
Avalanche
As we traversed a 20-degree slope, we remotely triggered an avalanche from 900 feet away, crossing various terrain features and rocky outcrops. We had felt and heard several rumbling collapses along the way.