Northern San Juan
AvalancheKrista Beyer · Nov 29, 2025 · Northern San Juan
Weather
Local weather stations measured a recent increase in northwest wind speeds. Temperatures above 12,ooo ft have generally remained below freezing. Last snowfall in the area was November 24th followed by generally clear weather and cold overnight temperatures.
Snowpack
Northeast slopes are where we've seen most of our avalanche activity due to winds and snow from November 16-24th, developing slabs over old weak snow from October. Cold temperatures have promoted surface faceting of this recent snowfall. Combine this with the recent winds pressing surfaces into firm slabs of snow, and we're beginning to see multiple slab-over-weak-layer combinations. Avalanches produced by these weak layers are still small and still isolated, but have gained some connectivity. Other slopes are showing the impacts of recent strong winds through patchy soft to firm conditions and raised tracks. Cold temperatures combined with a shallow snowpack is promoting faceting of the recent snow.
Avalanche
The avalanche I came across was reported in this observation: https://avalanche.state.co.us/report/3f8ff327-00c7-42da-8b06-6c985a704980. It was triggered where recent winds drifted and pressed snow into firm slabs above weak small-grain facets near the surface. It was triggered in an area with previous ski traffic, however, recent tracks had been filled in and covered by drifted snow. The crown of a nearby avalanche on a similar slope that was reported on November 24th, had mostly filled in.