Vail & Summit County
AvalancheAnonymous · Apr 21, 2018 · Vail & Summit County
Weather
Grizzly Couloir, Grizzly Peak. N/NE aspect. 12,750'. Overcast. Occasional, very light snow fall. Windy. Felt like NE winds, probably blowing in the teens consistently with 30 mph gusts.
Snowpack
Grizzly Couloir, Grizzly Peak. N/NE aspect. 12,750'. Didn't dig any snow pits. But their is a very apparent dust later in the area. N and E facing cornices are extremely large, likely due to the warm and windy storm cycle from 4/6 - 4/9. Similar cornice growth to the Ten Mile.
Avalanche
Grizzly Couloir, Grizzly Peak. N/NE aspect. 12,750'. The avalanche occurred in a N/NE facing couloir, above tree line. Due to the large cornice blocking our entrance to the couloir we decided to dig our way through the cornice and cut away as much as possible with shovels and skis. After attempting to cut a large section of overhanging cornice (10 ft. long, 5 ft. wide, 7 ft. deep) a member of our party, Skier 1, set up a rappel with a backup to more safely manage the cornice hazard. After a few attempts Skier 1 was able to successfully kick off the large block of cornice. However, this then triggered a much larger cornice fall. The subsequent cornice fall was approximately 40 ft. long, 15 ft. wide, and 5-15 ft. deep. The cornice fall then triggered an additional avalanche within the slide path. Due to the damage done to the couloir's snow surface by the cornice fall it was difficult to determine specifics about the triggered avalanche. However, based on our observations the avalanche most likely broke just below the cornice and entrained snow as it traveled down hill (SS-AS-R2-D2.5-O). The avalanche broke approximately 40 feet wide and ran 1500 vertical feet. It was difficult to determine the depth of the slide due to the cornice damage.