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Observation: Colorado Bowl

Observation Date
3/13/2022
Observer Name
Trenbeath
Region
Moab » East Side of Geyser Pass » Colorado Bowl
Location Name or Route
Colorado Bowl
Weather
Sky
Broken
Wind Direction
South
Wind Speed
Moderate
Weather Comments
Clear in the morning with increasing clouds and southerly winds throughout the day ahead of a storm system tracking through to the north.
Snow Characteristics
Snow Surface Conditions
Powder
Dense Loose
Melt-Freeze Crust
Damp
Snow Characteristics Comments
Spring conditions are in effect with all surfaces sun affected including many low angle northerlies.
Red Flags
Red Flags
Collapsing
Poor Snowpack Structure
Red Flags Comments
Folks I spoke with at the TH reported a collapse. I walked around for an hour in untraveled, forested, northerly facing terrain without a collapse. When I stopped to dig my second pit of the day (11,076' E aspect) the slope collapsed. It was a short, low angle slope above a bench that rolled over into a steep slope below. Had I been below the bench on the steep slope, it would surely have avalanched. The snow structure remains poor with a slab 2'-3' thick sitting on facets that formed during the Jan-Feb high pressure. The faceted layer ranges from about 20 cms thick to nearly the entire lower pack in shallow areas below about 10,000'.
Avalanche Problem #1
Problem
Persistent Weak Layer
Problem #1 Comments
This problem isn't going away, at least not until the entire snowpack goes isothermic. And in the interim, it may be a conduit for wet slabs if things really heat up. For now it seems that human triggered avalanches remain likely on this weak layer. Near treeline and below it is widespread on slopes facing NW-N-NE-E. At lower elevations there isn't as much of a slab on top, and it seems to have relaxed a bit but it's there. I got results of ECTP 29 with a very clean sheer on a NE aspect at 10,500'. I didn't experience any collapsing in the area, but the snowpack beneath the failure was faceted to the ground with an HS of about only 90-100 cms.
Then I dug this pit just above 11,000' and the slope collapsed while I was digging. The faceted weak layer was also "sandboxing" out. Not impressed.
Snow Profile
Aspect
East
Elevation
11,000'
Slope Angle
25°
Comments
The places I dug today are in areas where the PWL is most widespread - near treeline and below. On slopes facing NW-N-NE-E, this problem is going to be with us for awhile, and there isn't much winter left. Terrain above treeline remains a wildcard. The location of the PWL is variable, but where it does exist, it is more stressed by wind drifted snow. Some slopes may be strong and deep while others may have slabs 3'-5' deep on top of facets. For my money, it's not shaping up to be a strong spring in the La Sals, and for the near future, I can't see getting on any steep, north facing slope.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates