Observation: Powder Park

Observation Date
1/4/2021
Observer Name
Seth Dromgoole
Region
Salt Lake » Big Cottonwood Canyon » Mill D North » Powder Park
Location Name or Route
Powder Park 1
Red Flags
Red Flags
Wind Loading
Cracking
Collapsing
Poor Snowpack Structure
Avalanche Problem #1
Problem
Persistent Weak Layer
Comments
I'm not one to submit observations and/dig pits, as there are many people in the Wasatch doing this and I read their obs and learn. However, I found today a very unusual day of collapsing. Headed out to Powder Park 1 and skied low angle WNW facing slope. Set my own skin track through an aspen grove to get a little extra workout. The entire way up the skin track (starting at about 9200 ft on that same WNW aspect) heard and felt open areas in the aspen meadow settling/collapsing. A few times it happened I noticed about 100 ft away small aspens poking up through the snow still moving from the movement of the entire snowpack. Near the ridge I found a small test slope of about 30 degrees and walking on it caused the entire slope to collapse with shooting cracks about 100 ft. I didn't perform a full ECT as it was pretty obvious how connected the slab is and how easily it propogates. I did dig down to the ground to take a look at the snowpack. I would say depth was about 3'. The top 1/3 to 1/2 of snowpack was a cohesive slab. The remainder of the snowpack was large facets. Failure was on the interface of the facets and the slab. No crust noted, so either it never formed on this aspect/elevation or it has broken down into facets. The snowpack is going to be touchy with any new loads of snow. With snow and wind forecasted for tonight and tomorrow I anticipate a High rating for tomorrow and perhaps the next day.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
High