Observation: Public

Observation Details

Signs of Unstable Snow

Observations

Traveled up Commonwealth and to the top of Kendall trees to take a look at the wind-loading and get a feel for how the recent storm snow was bonding. On the way up, convective showers were producing heavy snow and I found a couple of fresh natural Dry Loose avalanches had covered the skin track just after the clearing with the waterfall. I later counted 10 people who had crossed that slope before the avalanches came down.

At the top of the trees, I found a few guys with a pit already dug, so I hopped in with them and we found 26cm over the 4/9 interface and 47cm over the 4/7 interface, composed of a mix of precipitation particles and DFs. The 4/7 crust is 16cm and knife hardness, with melt forms found below it. CT results were inconsistent, but did show failures on a density change in the HN and also failures below the 4/9 and on top of the 4/7. ECTX.

There was plenty of wind-affected snow with fresh drifts, textured surfaces, and cracks/blocking during uptrack tests near the top of the trees. At 11:30, the sun came out and within 15 minutes there were two new avalanches coming out of the upper Kendall cliffs. One was triggered by snow falling off the rocks and triggering a Dry Loose. The other I couldn't see the top of, but it may have been triggered by a skier and may have been a Wind Slab. Looking across the valley I could spot a shallow slab that had released in a couloir on Guye Peak, which propagated nicely. Plenty of Dry Loose sluffing coming out of steep rocky areas on most slopes that I could see. There was also some large old Wet Loose debris coming off the upper Kendall paths that was covered in this week's fresh snow.