Observer Name
Zimmerman-Wall, Kelly, Woody
Observation Date
Tuesday, March 25, 2025
Avalanche Date
Tuesday, March 25, 2025
Region
Provo » Provo Canyon » South Fork Provo R. » Cascade
Location Name or Route
Cascade North Summit
Elevation
10,800'
Aspect
East
Slope Angle
Unknown
Trigger
Skier
Trigger: additional info
Unintentionally Triggered
Avalanche Type
Cornice Fall
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
3.5'
Width
200'
Vertical
2,250'
Comments
This avalanche was an unintentionally triggered cornice fall that then triggered the persistent weak layer (PWL) facets (dry snow) near the ground on a very steep (greater than 40 °) hanging snowfield. This was a repeater avalanche. What was interesting is that the hanging snowfield was all faceted snow that failed near the ground, but the runout zone and the rest of the bowl which had slid a number of times earlier this season only entrained the surface snow on it's way down slope.
We had discussed cornice hazard as one of our problems for today, and had mentioned staying back from the ridge to be safe. While we were transitioning from skins to skiing, this avalanche was triggered by one of our party members putting the tail of their ski into the slope on the backside of the cornice. This is what triggered a massive collapse and the subsequent avalanche. Best guess on dimensions, 3'-4' deep x 200' wide running between 2,300' and 2,400' vertical feet.
Comments
Coordinates