Observation: Public

Observation Details

Signs of Unstable Snow

Observations

We toured up to the large gully on the S face of Lundin peak at the north end of Commonwealth creek. Snowpack felt largely safe throughout the early part of the day, though as we climbed above 5,000ft we noticed a 5inch storm slab sitting on a slightly firmer crust that we felt merited investigation. At 5,500ft, approx 300 vertical ft below the saddle, we dug a pit to do a basic column test. The column we isolated was approximately 60cm deep into the snowpack. After sawing the sides of column, and as we sawed the backside of the column, a clean slab 40cm down popped suddenly with no tapping from the wrist/elbow/shoulder required. It was a classic “cash register” pop and the weak layer appeared to be sugary facets. This surprised us quite a bit. Given the surprising results, we began to isolate a second column and had the exact same results happen again, with the slab cleaning sliding while we sawed out the back side. Given the results, we chose to not go any further and carefully skied down from where we dug the pit. Upon skiing down we saw no movement from the 5in deep storm slab we had initially been concerned by, and no movement from the deeper, 40cm deep layer we found.