Sign Up for the Utah Snow and Avalanche Workshop (USAW) on December 7th!

Observation: Little Cottonwood Canyon

Observation Date
11/21/2023
Observer Name
Kelly, SSP
Region
Salt Lake » Little Cottonwood Canyon
Location Name or Route
Little Cottonwood Canyon
Weather
Sky
Clear
Wind Direction
North
Wind Speed
Calm
Weather Comments
Temperatures were inverted. Cold in the morning and above freezing at the highest weather stations through the day. Snow surface on solar (south and west) facing slopes took some heat and rollerballs were noted in steep west facing terrain.
Comments
Snowpit on a northeast facing slope at 9800' failed with an extended column test with propagation at 16 taps on a weak faceted layer above a dirt crust a foot off the ground. The snow at this location was 3' deep and the bottom foot of the snowpack (closest to the ground) was a mix of weak faceted snow and breakable crusts. This layer that failed in the video below repeated with a compression test (CT15 SC) and a propagation saw test (PST 30/100(end)).
After spending a few days cruising around in upper Little Cottonwood Canyon I have observed that the snow is variable, particularly in height, and that the new snow from last weekend's storm was more wind affected in some areas than in others. What has been consistent is weak faceted snow with breakable crusts exists within the bottom layers of the snowpack. These weak layers of snow close to the ground were the culprit in the rider triggered avalanche in Rocky Point from November 19, 2023 and similar to the snowpack that Ambler/Smith submitted from Patsy Marley on November 20 and O. Crandall submitted from West Bowl on November 20th.
What all this weak snow close to the ground tells me is that areas that are holding snow from October and November are suspect and I will be checking to see how the old snow on the ground looks before committing to any steep terrain particularly if there has been any wind loading or if new snow falls. The good news is that these weak layers can heal with time and in a lot of places where there is little to no snow on the ground these layers aren't there.
Video
Today's Observed Danger Rating
None
Tomorrows Estimated Danger Rating
None
Coordinates