Southern San Juan
AvalancheChris Bilbrey · Jan 23, 2021 · Southern San Juan
Weather
Steady snowfall for most of the day with brief breaks in the clouds. We found 12 to 16 inches of new snow in the past 36 hours and close to 2 feet since January 19th. Clearing skies by the time we headed down canyon in the late afternoon.
Snowpack
Recent snowfall is lower-density stacking up quicker in volume versus snow water equivalent. This area has accumulated close to 2 feet since January 19th but fairly good bonding observed between storm cycles and in mid-storm layers. Compression Test produced easy failures within storm snow and below but non-propagating results in Extended Column Test. The snowpack below treeline on northerly-facing slopes is fully faceted below January snowfall and thickness of same facets is less as you climb above 11,000 feet. Although our CTs produced hard failures in weaker facets and non-propagating results in ECTs, this layer remains the biggest concern during our current loading period. As snow totals continue to add up, weaker facets will most likely be pushed toward tipping point. Newly formed storm slabs got stiffer as we transitioned out of below treeline and into near treeline with plenty of drifting observed along ridge tops and off peaks during breaks in the clouds. We observed minor cracking out in front of our skis but none shooting outward across slopes and only isolated collapses.
Avalanche
Easily triggered small but long-running loose sluffs on slopes near 35 degrees facing northwest, north, and northeast. Observed several natural loose dry sluffs out of steeper terrain and one cornice fall that triggered a D1.5 on a northeast aspect near treeline.