Steamboat & Flat Tops
AvalancheAustin DiVesta · Feb 11, 2022 · Steamboat & Flat Tops
Weather
Mostly cloudy and cold for most of the day. Winds below treeline were light from the west but moving closer to treeline winds became moderate. Clouds thickened closer to treeline allowing us not much visibility.
Snowpack
We traveled on most aspects below and near treeline. Below treeline, we noticed lots of cohesionless snow at the top 10-20cm of the snowpack and then a relatively stiff midpack. This cohesionless snow produced a couple of small Loose Dry avalanches in extreme terrain. We noticed a couple of crust/facet combinations as we moved towards southerly aspects in the upper 50cm of the snowpack, which might become problematic once we get new snow, but was not an issue today. When we moved towards ridgetops near treeline, the snow surface changed to a stiff 5-10cm wind slab resting on top of slightly weaker snow below it. We found the snow height to be about 225cm deep near the ridge top on a wind-loaded slope. Probing around found a relatively supportive snowpack that did not “drop” my probe deeper into the snowpack indicating weak layers below. An Extended Coloum Test did not produce propagation through the entire column, but we had a couple of breaks that did not propagate with easy to moderate taps in the upper 30cm of the snowpack. When we moved into the cloud ceiling we noticed rime starting to form on trees and any of the new snow that fell was slightly rimed. As we began our descent, the snow had started to pick up a little bit adding a little bit of new snow to the skin track we had set
Avalanche
Could of very small Loose Dry avalanches in extreme northeast terrain below treeline. They did not run very far due to the steepness of the pitch, but in steeper terrain they could run long distances.