Front Range
AvalancheAnonymous · Mar 24, 2018 · Front Range
Weather
On Flattop Mtn Trail (ridge) 11,843 ft: W/NW wind 20-30 gusts to 40mph, clear skies/sun Base of couloir 10,145 ft: 35-40F, sunny, no wind
Snowpack
Top of couloir: wind-deposited snow, not slabbed, below cornice, some icy spots at 50-degree entrance.
Avalanche
At the top of the couloir, we were closely considering the wind slab possibility. We decided to ski it, deciding that the snow below the cornice would not be slabbed and would be stable. However, standing in the cold winds at the top, which helped us for the first half of the couloir, we had tunnel vision and did not consider how notably different the weather would be in the lower part of the couloir. Halfway down the couloir, the snow became heavier (wetter), the wind disappeared, and the sun cooked the snow in the middle of the couloir. Skier 1 stopped in a safe zone in the shade along the cliff wall. Skier 2, skiing down the middle of the couloir, triggered an avalanche that released at him and propagated in the sunny, south-facing rollers on the side of the couloir, releasing from three different spots. It left a 7-inch crown in each of these places. The slide propagated slowly and ran to the base of the couloir, about 600 vertical feet. Skiers 1,2,3,4 descended the rest of the couloir slowly and deliberately in the shade along the cliff side. Slide was R2/D2.