Observation: Days Fork

Observation Date
2/4/2021
Observer Name
Greg Gagne
Region
Salt Lake » Big Cottonwood Canyon » Days Fork
Location Name or Route
Days Fork
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Direction
Northwest
Wind Speed
Light
Weather Comments
Very light winds from the northwest with periods of light snowfall.
Snow Characteristics
New Snow Depth
8"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments
20-25 cms new snow from Wednesday/Thursday morning, topped off with very-low density stellars. Recent warmth prior to this last storm had crusted the old snow surface below about 8500'. Wednesday storm came in denser with some graupel, but it had bonded well to this old snow surface.
Snow depths are 1-1.5 meters.
The top 5-10 cms would sluff very easily on steeper aspects.
Red Flags
Red Flags
Recent Avalanches
Poor Snowpack Structure
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #1 Comments
Going with increasing danger with more snowfall and wind in the forecast. (Not necessarily a High danger, but that it may become more likely to trigger an avalanche.)
Comments
Lots of quick pits today plus wanted to look at the remotely-triggered slide from Tuesday on Chicken S&!t Ridge (CSR). The CSR slide was 2-3' deep, failing on faceted snow that formed earlier in January. I was able to safely access the flank of it, and was unable to isolate a column (CTC and ECTPV) as it would fail on this same persistent weak layer.
Other pits on East as well as Southeast aspects were ECTN, failing down 45-60 60 cms just below the Jan 23 weak layer.
We did not get any collapsing or cracking today, and I feel the snowpack is now giving us fewer indications of its instability. But the structure of a stronger slab on top of buried PWL remains a concern, and travel advice is still to avoid steep mid and upper elevation aspects facing west through east. Fortunately, lower-angled slopes are riding quite well!
Photos and video of Tuesday's CSR remotely-triggered slide. (ASr-R2-D2-O)
Video
Honestly unsure if additional wind and snow (with water possibly exceeding 0.5") will be enough to make the PWL active. Any new snow and wind-drifted snow will be reactive on top of the current surface of low-density stellar, and I wouldn't be surprised to see sluffing and soft slabs on Friday, especially during any period of higher precipitation intensity (PI).
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable