Snowmobile triggered crown profile and more pits

Snowmobile triggered crown profile and more pits

Date
Activity
Snowmobiling

We rode to Daisy Pass to look at the avalanche that was triggered by a snowmobiler two days ago (12/6/22). It was on the slope east of the pass that people often climb up and out, steeper than the normal route out. It broke 2-3 feet deep and 250-300’ wide, R2-D2. At the crown it broke on a weak layer about 100cm above the ground, but it broke closer to the ground in many places lower on the slope where the snowpack was shallower and weaker. I would guess one of those areas is where it was triggered from.

Next, we rode around the back of Fisher Peak to Lulu and dug on the southwest slope below the weather station. Here it was shallow, 100cm. There were weak facets near the surface, but no slab on top of them, maybe due to the southerly winds scouring it. Could become unstable if loaded from the north or with a lot of new snow. Finally, we rode up to the shoulder of Scotch Bonnet and dug on far south Rastas. HS was 145cm, we had ECTP22 and ECPT27 on a thin layer of facets sandwiched between two crusts 55cm off the ground. Despite the hard force, these collapsed dramatically and re-iterated the possibility of triggering a large, high-consequence avalanche.

 

Region
Cooke City
Location (from list)
Daisy Pass
Observer Name
Alex Marienthal