Avalanche: Cardiac Ridge

Observer Name
Cawley
Observation Date
Sunday, February 14, 2021
Avalanche Date
Saturday, February 13, 2021
Region
Salt Lake » Big Cottonwood Canyon » Cardiff Fork » Cardiac Ridge
Location Name or Route
Cardiac Ridge
Elevation
10,600'
Aspect
East
Slope Angle
38°
Trigger
Natural
Avalanche Type
Soft Slab
Depth
3'
Width
400'
Vertical
1,250'
Comments
I'm declining to include a weak layer on this observation because the light was not outstanding and the avalanche had a bit of new snow on top when we observed it from Toledo saddle at about 2 PM today. But I'm inclined to think it's a new snow/storm snow avalanche that ran during the highest PI on the evening of 2/13 and failed in pooled graupel or some other density change from 2/12; there was no vegetation, textured or discolored snow, or chunks of hard slab on the bed surface or in the debris. The low density snow entrained in the slide ran all the way to the bottom of the ski run, though not quite to the creek, and triggered a step-down halfway down the path below a bushy bench.
Another possibility is that this avalanche does involve an older weak layer and perhaps it ran much earlier during the 2/12-2/14 storm, with hard slab debris now covered in 1-2' of blower. But I don't think it was a grounder.
We also saw another new snow pocket in the steep ESE facing terrain beneath the cliffs south of Hansen's, and a few real-looking avalanches on the flanks of High Pockets etc. on Kessler. There were a couple skier-triggered, warm snow soft slabs in the early afternoon on S-SW facing Flagstaff.
Coordinates