Northern San Juan
AvalancheMatt Huber · Feb 21, 2021 · Northern San Juan
Weather
Mostly clear skies with increasing cloudiness to the north as the afternoon progressed. Winds increased and by 3:00 PM most ridgelines had obvious plumes of blowing snow from northwest winds.
Snowpack
Near treeline the snowpack depth ranged from 75 to 100 cm. The surface is a fragile wind/sun crust sitting on 1-2 inches of recent snow. The top 1/3 of the snowpack is a 4 finger slab, on sunny slopes separated by an unreactive suncrust. At about 65 cm from the ground the entire snowpack becomes a fragile and uncohesive mass of 5-7 mm depth hoar. Extended column tests produce easy propagating results with 9-10 taps. Above treeline, winds have stiffened and scoured most surfaces, my biggest concern would be triggering a deeply buried weak layer from the shallow portions of cross-loaded slopes
Avalanche
A few old Wind Slab avalanches on repeat offender southeast-facing slopes and cross-loaded west-facing slopes