Avalanche: Little Superior

Observer Name
Observation Date
Saturday, April 20, 2024
Avalanche Date
Saturday, April 20, 2024
Salt Lake » Little Cottonwood Canyon » Little Superior
Location Name or Route
South ridge of Little Superior
Avalanche Type
Wet Slab
Avalanche Problem
Wet Snow
Weak Layer
Wet grains
Two of us were skiing down the south ridge of Little Superior when we triggered a wet slab. I watched it propagate below me well over a hundred feet across the slope in just a second or two. At the same time, the skier a hundred feet above me noticed separate cracks propagating and that he was also within the starting zone. We felt that we had both triggered this fat slab.
We were lucky that the slab accelerated slowly and remained cohesive. I was able to patiently pick up speed and steer off the high side. We didn't stick around to investigate. Presumably, it broke on a weak, wet, and perhaps percolating interface between the 25cm of surface crust and the moist snow below (April 15 storm?)
In the photo, the red line roughly indicates the start zone. Some new debris from this slide (perhaps R2D2 in size) overlays older debris.
The snowpack had received close to 3 hours of direct sun from 11 to 2PM, around time of the event. There were a few minutes of shade here and there from altocumulus (mackerel sky) and cumulus cover. The breeze was minimal, and temperatures reached near 50F.
We had already skied our objective and this was simply the exit. We had seen a few natural wet slides on cardiac ridge and were wary of setting off more entrained, wet sloughs. However, this wet slab was unexpected.