Quick report
- Red Flags
- Recent Avalanches, Heavy Snowfall, Wind Loading, Cracking, Poor Snowpack Structure
This morning, we toured from the Flagstaff lot to Cardiff Pass and skiied south-facing terrain in Cardiff Bowl. I did not include PWL in the avalanche problems above because we were not on any northerly terrain and did not observe the PWL. The day started fairly cloudy (80% covered) but was bluebird by afternoon. Plenty of solar energy hitting sunny slopes. Surface conditions on all aspects were deep powder, with knee-deep skin tracks. Some light gusty winds in the morning but generally calm & getting calmer later in the day.
Snowpack
- Instability Comment
- <p>Seeing the considerable danger on high- elevation southerly slopes for soft slabs, we began our tour with a conservative mindset, red-lighting any slopes with consequence and determined to gather more info before considering avy terrain. However, we observed safer avalanche conditions in this area than the forecast would suggest. It was not possible to pull a cohesive block off in a hand shear (mitten simply passed through the isolated block); shovel shear tests would not break on a planar surface; 2 ECTXs (although we considered these unreliable given the nature of the avalanche problem); and a few test slopes failed to show any signs of activity. Given these promising signs, we deemed it safe to ski a low-consequence slope slightly above 30 degrees, to skiier's left of the standard skinner up Cardiff Bowl. No activity noted. Moreover, skiing at Alta later in the day, I noticed a large number of tracks in the Cardiff, Flagstaff, and Emma areas with no slides. While conditions seemed pretty stable in this location, it's important to note that conditions may be different in other areas of the Wasatch, where the snow may be more inverted or there may be a more cohesive slab on the density inversion. Additionally, avalanche control work done during the storm to protect the Town of Alta may have lead to unrepresentative additional stability in this area.</p> <p>Given high winds overnight and obvious signs of wind transport on lee sides of ridges, we were sure we'd see some wind slabs on our tour today. Sure enough, while making a kick turn on the south face skinners right of Cardiff Pass, I was able to stomp above the switchback and generate a shooting crack. We also noted a pillowy feature of snow ahead (east) of us, downwind of a large rock feature that could have caused a wind eddy. Given these signs of wind loading, we declined to traverse further onto the slope and skiied fall line from where we stopped. I would expect abundant wind slabs across the Wasatch, which may remain a problem for a few days (or longer with more wind). Furthermore, on shady lee aspects, I suspect wind loading could have created a thicker and more dangerous slab on the PWL.</p>