Observation: 10420

Observation Date
1/1/2021
Observer Name
Hardesty and Sarfati
Region
Salt Lake » Big Cottonwood Canyon » 10420
Location Name or Route
West Ridge of 10420
Weather
Sky
Clear
Weather Comments
Glorious.
Snow Characteristics
New Snow Depth
1"
New Snow Density
Medium
Snow Surface Conditions
Powder
Snow Characteristics Comments
Small grain SH sits atop the recent 1" storm snow.
Excellent riding on low angle.
Red Flags
Red Flags
Cracking
Collapsing
Poor Snowpack Structure
Avalanche Problem #1
Problem
Persistent Weak Layer
Problem #1 Comments
We found multiple ECTNs with tests but did experience some cracking and collapsing on north facing terrain at about 10,000'. I guess I shouldn't have been surprised that all the usual avalanche paths (Lane's Leap, etc) had run during the cycle. One newer pocket looks like it was skier triggered a couple days ago, perhaps 16" deep and 40' wide east of Lane's.
This is where it gets interesting with inconsistent test results and occasional cracking and collapsing. Mark White's avalanche today in No Name so well exemplifies both the trickiness of PWLs and particulary PWLs in a Moderate danger rating:
  • Previous tracks on the slope
  • Surprised a professional who knows the snowpack history
  • inconsistent test results
  • diminished cracking/collapsing
  • Lots of stuff gets hit with no incident
  • Last avalanche on the 28th..ie - infrequent avalanching
Video
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
Coordinates