Northern San Juan
AvalancheJeff Davis · Nov 28, 2016 · Northern San Juan
Weather
Experienced a significant change in weather throughout the duration of the tour. Sky's were clear to start the morning, but quickly became overcast as a cold front brought strong westerly winds and snow. Snowfall ranged from S-1 to S2. New snow was being actively transported from windward to leeward slopes.
Snowpack
HS ranged from nil on windward slopes to drifts up to 3 feet deep. The snowpack in general is weak, as ski penetration is consistently to ground. Only pockets of surface slab were observed on ridgelines and in loaded pockets. Collapsing was observed in flat meadow areas. I was able to trigger a Storm Slab avalanche SS-AC-R1-D1 today on a loaded east facing slope just above treeline. The Cornice piece was length of my skies and approximately 2 feet wide. It ran on the ground and went around 400 feet.
Avalanche
Intentional cornice fall triggered Storm Slab avalanche on East facing slope just above treeline.