Northern San Juan
AvalancheSusan Hale · Apr 19, 2016 · Northern San Juan
Weather
Skies were clear early and gradually increased to mostly cloudy by 1-2pm. Intermittent sunshine, only very light winds and warm temps during the tour.
Snowpack
Very thin and moist pack below treeline on exposed easterly uptrack. Skied NE aspect originating at treeline, which had also become moist in any open terrain (heavily treed locations still had dry snow). The new snow was not bonded to the old dusty MF surface and was easy to sheet off under-foot. We managed to get a section moving down-slope that grew into a real avalanche...see aval ob
Avalanche
A ski cut at the top of our ski choice triggered a sluff under-foot that sheeted off the old dusty surfaces. In this steep terrain, the sluff gained steam and entrained more snow until the slope angle kicked back. There was no fracture or collapse, just poorly bonded snow. Interestingly another party had a similar experience in another drainage nearby.