Check out our Holiday Auction - Sign Up for the Utah Snow and Avalanche Workshop (USAW)

Avalanche: Monitors

Observer Name
Zack Little
Observation Date
Wednesday, December 15, 2021
Avalanche Date
Wednesday, December 15, 2021
Region
Salt Lake » Park City Ridgeline » Monitors
Location Name or Route
Katie's
Elevation
9,900'
Aspect
North
Slope Angle
33°
Trigger
Skier
Trigger: additional info
Remotely Triggered
Avalanche Type
Hard Slab
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
3'
Width
1,000'
Vertical
Unknown
Snow Profile Comments
Location of the avalanche is a typo– Katie's in the Wasatch Range, UT is correct.
Comments
We remotely triggered this very large avalanche(HS-ASr-D3-R2.5) from the ridge line approximately 15 feet away from the crown. The height of snow in the area varied greatly due to wind transport, averaging at 170cm with an average crown depth of 100cm. The crown length was approximately 1100 feet. This avalanche failed on .5-1mm facets above the most recent heat crust that were most likely buried on the 12/10 storm. This layer of concern lies 93cm from the ground, varying depth from the surface due to significant wind transport. Immediately below the bed surface we found slightly larger facets followed by a combination of crusts and facets to the ground. At the time of the avalanche significant wind transport was occurring from the SSW, as we traveled past the avalanche ~1hr later many of the shallower parts of the crown were mostly filled in. This was without a doubt a very serious avalanche and any involvement would surely have dire consequences. The width of the avalanche in addition to other very large observed avalanches on similar slopes today speaks to the connectivity of the snowpack after the most recent loading event. This avalanche also triggered a smaller but still significant sympathetic release avalanche pictured below.
Comments
Hardness profile of the crown.
Coordinates