Avalanche: Kessler Slabs

Observer Name
AM
Observation Date
Wednesday, April 10, 2019
Avalanche Date
Wednesday, April 10, 2019
Region
Salt Lake » Big Cottonwood Canyon » Kessler Peak » Kessler Slabs
Location Name or Route
Kessler Slabs
Elevation
9,900'
Aspect
Northeast
Trigger
Skier
Depth
8"
Width
40'
Carried
1
Comments
Heading up the standard Mower skinner this morning my partner and I noticed significant transport from sustained NE winds, creating touchy wind pillows that would crack at our feet anytime we took the skinner into the more north-easterly aspect of the ridge. These drifts cracked in a very predictable manner and produced shallow slabs (4" at most) that barely moved on the spongy crust underneath.
We started our first run (N facing Mower at 9900', more wind sheltered) by ski cutting a 35-ish degree section with no results and saw no signs of instabilities all the way down to the flats at 8600' (other than a really sluggish sluff).
The winds seemed to have increased when we got back to the ridge and the skinner had mostly filled in. We got back to our high point and decided to exit via a NE facing slope which drains into mellow terrain below the Kessler slab. The upper part of the slope is a steep bowl (mid-40s for a short bit) and was obviously wind loaded. I decided to ski-cut the narrowest section (about 50') with the goal of flushing the bowl. I aimed for a thick stand of large pines but the angle was too low for me to carry enough speed and fully get off the 6" wind slab which broke right at my feet. The cracks propagated about 80-100' above me and released a slightly thicker slab (didn't have much time to measure that one, maybe 10"). I was carried for about 10' in an upright position then stomped down on the bed surface (spongy crust) with both skis and went right through which stopped me.
We skied the bed surface until we reached the lower-angle and wind-sheltered terrain below. The slide traveled over a couple small low-angle cliff bands and stopped in the massive wet debris piles that came off the Kessler slab, about 1000’ from crown to toe.
Coordinates