Observation: Big Cottonwood Canyon

Observation Date
1/5/2019
Observer Name
Andrew McLean
Region
Salt Lake » Big Cottonwood Canyon
Location Name or Route
Lake Catherine
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Same
Problem #1 Comments
It wasn't much of a problem, but there was a bit of shallow (2") surface cracking in places and lots of faceting in the shallow areas around wind-blown rocks near ridgelines. These weren't problems today, but could be with a dose of new snow on top of them.
Comments
The evil wind has had its way with the snowpack and it's hard to find areas that aren't alternating settled powder and then knee ripping crust. Heavily sheltered, mid elevation, north facing trees seem like the place to be. Skinning and trailbreaking was tricky as the surface snow has broken down quite a bit and turned into high friction sugar, which is hard to get an grip in/on.
We traveled through a variety of aspects and angles between 9,000 and 11,000 today with no signs of immediate instability. In general, I'd say the avalanche danger is low everywhere we looked and skied, but there might be a few lingering pockets or wind slabs out there that still might come loose, (especially with explosives) but the snowpack seems strong enough to easily support a skier/rider's weight.
We did see an interesting skier triggered avalanche in a gully down below the Seagull on Tuscauroa, but I'm not sure when it happened. It looked like a group of skiers traversed into a side-loaded gully and popped loose a sizeable slab that ran down the gully, over a roll, through some trees and ended up right near Lake Martha. From the ski tracks, it didn't look like anyone was caught and I'm guessing this slide as at about 9.250' on a north facing slope.
I dug an inconclusive pit today:
West facing
10,038"
33 degrees
165cm depth
Many crusts and wind event layers in the snowpack, but the snow on top seemed well bonded.
Overall, good structure - mostly 1F all the way to the ground.
ECT test = 30/nil with some crumbly failures, but nothing crisp.
Compression test had a slow failure at 6 which didn't propagate or go anywhere, then it went to 30 with no other result.
Overall, I think the danger is low, but that could change with a new load of snow on top, however, if it comes in warm, I think it will bond well to the existing surface layer.
Today's Observed Danger Rating
Low
Tomorrows Estimated Danger Rating
Low