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Observation: Little Cottonwood Canyon

Observation Date
3/31/2023
Observer Name
Kelly
Region
Salt Lake » Little Cottonwood Canyon
Location Name or Route
Upper Little Cottonwood Canyon
Weather
Sky
Broken
Precipitation
Light Snowfall
Wind Direction
Southwest
Wind Speed
Moderate
Weather Comments
Winds calmed down below ridgetops and were gusting to strong from the southwest and dropping in speed as the skies cleared up. By late afternoon visibility was enough to see down canyon. Not much of a window to take a look at the snowpack so stuck to low angle slopes around the summer road that were not included in the UDOT backcountry closure.
Snow Characteristics
New Snow Depth
20"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments
New snow was low density powder snow and had a density change 2' down from the surface. As soon as the sun came out the surface warmed up.
Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Cracking
Collapsing
Avalanche Problem #1
Problem
New Snow
Trend
Same
Snow Profile
Aspect
South
Elevation
9,000'
Slope Angle
37°
Comments
This morning Alta hit 800" for the season. With a base depth of 229" at the Collins Study Plot and had a 6" an hour snowfall rate during one of the overnight hours. It has been an impressive year. A quick test pit showed a weak layer 3' from the surface that was broken stellars and small grained facets. This layer was reactive in extended column tests with propagation at 26 and 28 taps. It is located about 4-6" under the dirt layer in the below photo.
The dirt layer was similar to snowpits that forecasters found in other locations above a melt freeze crust. Drew found it in Parley's Canyon, Mark found it in Farmington Canyon, Greg found it in Big Cottonwood Canyon Bo Torrey found it in Days Fork(without a crust). While this dirt layer isn't everywhere in places where we found it it was associated with a melt-freeze crust that could have facets above or below the crust. These facets could become a player when the warm spring sun starts to beat down on the new snow surface and is worth keeping an eye on.
What stands out to me is that this pit and another pit in the Emma's from Monday both show a dry snowpack on southerly facing terrain. The sunny side has not seen much sun, which means it hasn't settled into it's spring coat yet. Give it some time to adjust. These 2 snowpacks look more like what I would expect to see on more shaded aspects.
Intact dirt layer 32"from the surface with small grained facets above a crust ( no results on this layer with stability tests)
Faceted broken stellars 3' from the surface
Photo of afternoon clearing
Today's Observed Danger Rating
High
Tomorrows Estimated Danger Rating
None
Coordinates