Observer Name
Grainger
Observation Date
Thursday, November 28, 2019
Avalanche Date
Thursday, November 28, 2019
Region
Salt Lake » Big Cottonwood Canyon » Silver Fork » East Bowl
Location Name or Route
Silver Fork East Bowl
Elevation
9,900'
Aspect
Northeast
Slope Angle
38°
Avalanche Type
Soft Slab
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
3'
Width
50'
Vertical
200'
Comments
If we're still with the house of cards metaphor the house is starting to topple on certain suits. Walking the Silver Fork (East Bowl) ridgeline today produced many collapses and showed different north-facing slabs propagate on buried surface hoar, the Nov. M/F crust, and Oct. facets/DH. Today's high PI rates and morning wind tipped the scales on many slopes and in a short time I was able to find multiple natural and human-caused avalanches.
The first two photos are from a NE-facing slope that fractured as I walked the ridge, felt a collapse and looked over the edge ~15 ft. away to see a crown to near-ground Oct. facets/DH. Crown up to 42" and 50' wide.
Comments
These 3 photos from a natural that likely occurred during highest PI rates late morning. A NNW slope, crown propagated ~240', averaged ~24", guessing it ran on the deteriorated M/F crust layer.
Comments
The first photo here was a gully that had the wall triggered from a skier track ~10 ft. away, The many collapses throughout the day produced results if they propagated to angles over ~35 degrees. The second photo occurred during high PI and failed on buried surface hoar preserved before this last week of snow. Triggered from the flats underneath ~25 ft. away.
Coordinates