Northern San Juan
AvalancheTroy Nordquist Chris Dickson · Dec 8, 2024 · Northern San Juan
Weather
The day started crisp and clear with an obvious temperature inversion. High cirrus clouds began to stream in from the west and temperatures warmed to above freezing as the day progressed.
Snowpack
Height of snow ranged from 75 cm to 85 cm on west-facing slopes NTL. On slopes with more solar input, percolation columns were observed along with faceted snow between melt-freeze form crusts. On less sunny westerly slopes, the crusts remained but the percolation columns were absent and grains near the ground were beginning to cup. On wind-prone slopes, there is an old one-finger-hard wind slab from mid-November that rests above facets. Both CT and ECT tests produced non-propagating failures above and below these crusts in four-finger and fist hard facets. Above treeline, the snow surface varied from faceted wind ripple to patchy thin wind skins. Nowhere on our tour was the snowpack deeper than a meter.
Avalanche
One lone, small loose dry avalanche was observed on a west-facing slope at an approximate elevation of 12,000'.