Quick report
- Slope Angle
- 36°
Avalanche
- Slab Width
- 24 m
- Weak Layer
- Facets
- Trigger Type
- Skier
- Vertical Fall
- 107 m
- Avalanche Type
- Soft Slab
- Slab Thickness
- 61 cm
- Trigger Detail
- Unintentionally Triggered
- Start Zone Aspect
- North
- Avalanche Problem
- Persistent Weak Layer
- Start Zone Elevation
- 3018 m
Our party of four headed up to Emma's ridge from the Alta parking lot. We skied the first line in silver fork without incident. We decided to ski the second line on a shadier, steeper slope closer to the cliff band. The first three skiers descended without incident, one at a time. During the last skiers run, an avalanche was remotely triggered behind him. From the bottom it looked like there was a second slide which fractured on facets/weak layer near the ground and higher up the slope and it appeared to break above the first which then combined with it and ran nearly the length of the slope. The last member of our group was far enough ahead of the slide and descended the slope without incident and was neither caught nor carried. All had beacons, probes, shovels and the last skier had an airbag. Definitely going to use this as a learning experience and be more cautious about our terrain choices. First large slide in 17 yrs of backcountry skiing and hope to never have another one. Very grateful that everyone in our group came out of this one ok.
Forecaster Comments: Thanks to the group for taking the time to speak with the UAC team soon after triggering this slide, and taking the time to put the avalanche observation in. We were able to get in to do a crown profile and found the avalanche failed on a layer of faceted snow 6" (15cm) from the ground. There was a unique second piece of snow mid slope that may have been an old ski track where the avalanche jumped the stauchwall, made a second slide and then pulled down the facets again before running out to the flats. Unlike the avalanche that was skier triggered on November 28th in Two Dogs the snow structure in this location had no crusts and no wind slab. (First photo with ski pole shows second crown). Read our full observation HERE.
Photo Below (AB)