Northern San Juan
AvalancheChris Dickson · Nov 25, 2025 · Northern San Juan
Weather
Clear with a few high cirrus clouds, but cold in the alpine, with temps likely in the low 20s. Winds were gusty out of the West, blowing snow along the ridgelines and creating some breakable wind-crusts on the snow surface in steep windward terrain.
Snowpack
The snowpack is faceting rapidly under cold clear skies, setting us up for a more widespread Persistent Slab avalanche problem when the next snowfall arrives. I dug a pit on a north-facing slope at 12,600 feet and found a 122 cm snowpack. Things are generally right-side-up, with softer snow over harder snow in the midpack. Towards the bottom, there is a stout, melt-freeze crust (about 20cm thick) from those warm days in early November, which is pencil-hard. Under this crust, is a mix of depth hoar and melt forms near the ground. Tests revealed a potential layer of concern in the midpack but no propagation. In general, I was pleasantly surprised to find such a thick and well-bonded midpack.
Avalanche
I observed one small D1-sized avalanche on a northwest-facing slope above treeline with a 2-foot thick crown. A second avalanche on a north-facing slope was larger, at D1.5, with an estimated 100-foot crown width and a runout distance of 300 feet. And lastly, three loose avalanches, all R1D1 in size, were spotted coming out of steep north-facing terrain, which likely ran during the storm.