Northern San Juan
AvalancheAnn Mellick Jeff Davis · Jan 27, 2021 · Northern San Juan
Weather
The day started cold and sunny, but clouds built through the day, with a few snowflakes falling in the afternoon. Steady SW winds. Overall, a cold winter day in the mountains.
Snowpack
Today, 4 of 5 red flags (no rapid warming) were observed. As the snowpack begins to adjusts to the recent large load southwest winds move snow near and above treeline. Winds efficiently moved lots of snow to lee slopes and stiffened exposed snow surfaces. Stiff surface slabs 1"-5" thick had formed on south and westerly terrain where we traveled by noon. We remotely triggered a small avalanche on a southwest from over 100 feet away and experienced lots of cracking and collapsing. An Extended Column Test on a west facing slope above treeline showed a weakness at the new and old interface. Avalanche activity, rumbling collapses and remote triggers all point to Dangerous Avalanche Conditions.
Avalanche
With the first good visibility in days, we were able to see some slides that ran mid-storm, as well as some fresh ones.