Observer Name
Hardesty and Manotti
Observation Date
Wednesday, January 15, 2020
Avalanche Date
Tuesday, January 14, 2020
Region
Salt Lake » Park City Ridgeline » Monitors » South Monitor Bowl
Location Name or Route
South Monitor
Elevation
9,800'
Aspect
Northeast
Trigger
Natural
Trigger: additional info
Cornice Triggered
Avalanche Type
Hard Slab
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
4'
Width
500'
Comments
All are estimates. Natural cornice failure due to strong winds seems most likely. Did not access crowns due to overhead hazard.
Strong southwest winds on Tuesday Jan 14th likely provoked a large natural cornice fall which in turn triggered a size 2 wind slab that in turn stepped down to near the ground. Arrows point toward grass/shrubs pushing through old snow near the ground. Repeater. Original avalanche during the Thanksgiving Cycle - Thursday - Thanksgiving, November 28, 2019 - as remotely triggered/reported by Mark White. Based on amount of snow on the bed surface, the avalanche likely ran during frontal passage just after noon.
Comments
Had been concerned - with the 60-100" (3.5-6.3" SWE) since New Years along with the strong SW winds that some repeaters might come back to life. I suspect that there may be a few more out there. Seems like the major window was yesterday/Tuesday and perhaps tomorrow/Thursday with the strong winds...and then may prove more stubborn in the days ahead.
Comments
Forecaster Comments: Thanks to all that submitted info regarding this avalanche; we could save only one observation for our record keeping.
Video
Coordinates