Northern San Juan
SnowpackChris Bilbrey Ann Mellick · Jan 5, 2021 · Northern San Juan
Weather
A mixture of clouds, sun and intermittent snow showers. Winds increased with elevation and by early afternoon, strong northwest winds were forming shallow wind-drifted slabs in the alpine below ridgetops on leeward slopes.
Snowpack
The snowpack in this part of the zone is generally shallower than we have seen in other regions (under 1 meter on shady slopes, with only 10-25 cms on due south facing slopes). Snow depths below about 10,000 feet are hardly deep enough to recreate on safely and abundant natural obstacles lurk below the surface. The pattern is the same as we have seen elsewhere in the zone: fragile snow structure with a fair amount of cracking and collapsing, especially on shady slopes around 35 degrees. Planar failures in Compression Test and propagating results in ECTs with moderate force does not inspire confidence to travel in steeper terrain. Strong northwest winds along ridge tops were forming shallow soft slabs and we observed a small slide run naturally, but it did not travel the full distance of the steep couloir.