Observation: Little Cottonwood Canyon

Observation Date
2/3/2024
Observer Name
Gagne/Duvernay
Region
Salt Lake » Little Cottonwood Canyon
Location Name or Route
Upper LCC Periphery
Weather
Sky
Obscured
Precipitation
Light Snowfall
Wind Direction
Northwest
Wind Speed
Moderate
Weather Comments
Very poor visibility with periods of occasional light snowfall. Sustained winds above 9,500'
Snow Characteristics
New Snow Depth
10"
New Snow Density
High
Snow Surface Conditions
Powder
Wind Crust
Snow Characteristics Comments
Some graupel in the new snow.
Red Flags
Red Flags
Wind Loading
Cracking
Red Flags Comments
Cracking on slopes that were wind-loaded.
Comments
Traveled quickly today while trying to cover ground, and for the first time in what feels like forever*, I did not dig down to the PWL. Today I focused on the new snow, in particular:
1. How the snow since Thursday night has bonded to the old snow surface: Several quick pits on slopes up to 10,400 on all aspects showed the new snow came in right-side up and bonded well to the old snow surface.
2. Weaknesses within the storm snow: The storm snow came in warm and dense, and generally was lower-density when the flow switched to the northwest on Friday evening. The only weakness I could identify was a density inversion down 5-10 cms (2-4") which was capped with denser snow containing graupel. This density inversion should heal quickly (within a day).
3. Wind effects: We found wind-drifted snow along ridgelines that were 10-15 cms thick and would propagate short distances.
Overall, it seemed to matter where the wind-loading was occurring. Outside of wind-drifted terrain, the storm snow was unreactive. On wind-drifted slopes, cracking in the soft wind drifts was common. For Sunday, the biggest issue will be slopes that were wind-drifted.
* Likely the first time this season I did not look at faceted snow. The facets are gaining strength and the slab on top is getting deeper and stronger, but avalanches failing in the PWL can still be triggered from thin spots on the slope. I continue to avoid steep, rocky, north-facing terrain where there are facets and the snowpack is likely to be thinner.
Today's Observed Danger Rating
None
Tomorrows Estimated Danger Rating
None
Coordinates