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Observation: Alta Periphery

Observation Date
11/29/2020
Observer Name
Champion, Coyne and Tatly
Region
Salt Lake » Little Cottonwood Canyon » Alta Periphery
Location Name or Route
Catherine's Pass
Weather
Sky
Clear
Wind Direction
Northeast
Wind Speed
Light
Weather Comments
Warm bluebird day, temperatures ranged in the mid-20s to 30s. Winds were calm to light throughout the day, with no signs of transport.
Snow Characteristics
New Snow Density
Low
Snow Surface Conditions
Powder
Faceted Loose
Melt-Freeze Crust
Damp
Snow Characteristics Comments
A variety of snow surfaces exist in the backcountry. Across the board the snowpack continues to deteriorate, the South end of the compass continues to get damp during the day, and freezes overnight. The snow surface is even getting damp on lower elevation North-facing aspects that aren't in the shade all day. The mid and upper elevation North aspects are still holding onto some cold soft snow, and that's where the best riding is, but the new snow is beginning to deteriorate and facet.
Red Flags
Red Flags
Poor Snowpack Structure
Comments
The main concern currently continues to be low-tide riding conditions, things are still shallow and only getting shallower. There could still be a few lingering wind-drifts at the uppermost elevations where the snow has been protected and cold.
The big red-flag is the current snowpack structure, and what will happen next time we do a lot of precipitation on top of it. Today on a SE aspect around 9500' in Upper Little Cottonwood Canyon it is still easy to find the stout supportable melt-freeze/thermal crust from last week under a few inches of the new snow. Surrounding that melt-freeze crust is faceting snow both above and below this crust. This weakening snow is found wide-spread surrounding that melt-freeze crust on any southerly's that it exists. On upper-elevation Northerly's that don't possess this melt-freeze or thermal crust, the entire snowpack is faceting out or "sandboxing" as a few-observes have pointed out.
While overall the snowpack is currently right-side-up and doesn't cause us much trouble right now it will become a problem once we add any type of slab or load on top of this structure.
Photo of the generally right side up snowpack found on a SE aspect in Upper Little Cottonwood Canyon, around 9500'. You can see the 4F hard snow below the 1F hard MF crust and F hard snow above the 1F hard MF crust. Surrounding the 1F hard MF crust is faceting snow.
A better look at that stout 1F MF crust 8-10cm down in the snowpack.
Today's Observed Danger Rating
Low
Tomorrows Estimated Danger Rating
Low