Steamboat & Flat Tops
AvalancheMax Strotbeck · Dec 30, 2023 · Steamboat & Flat Tops
Weather
Skies were mostly clear. Light westerly winds. Temperatures in the morning around 15° degrees climbing to near-freezing by 2pm. No new snow.
Snowpack
Traveling between 9,400 to 10,200 feet today on west through north through south aspects, height of snow ranged from 82cm on 126cm where probed. Ski penetration was generally about 15cm while foot penetration was about 35cm, stopping in the midpack slab around where it became 1 finger hard. We observed a widespread layer of surface hoar 5mm-30mm in size on the surface of all aspects traveled both in forested terrain and open meadows. Below 17-20cm of fist hard snow from our most recent storm over Christmas is a potential layer of concern moving forward, a 2cm layer of 15-20mm buried surface hoar found in snowpits dug on west through north through east-northeast aspects. In extended column tests, fractured initiated on this buried surface hoar layer with moderate taps but did not propagate. In one snowpit on an east facing slope, we found evidence of a decomposing surface hoar layer buried 42cm. In an extended column test we had subtle propagating results with hard taps on this layer (ECTP24), but a second test yielded no propagation on this layer (ECTN25). In a snowpit on a southeast aspect, we did not find buried surface hoar, but rather a 1cm melt-freeze crust about 20cm down sandwich by a thin layer of facets and rounding facets. In an extended column test, a fracture initiated with hards tabs below this crust but did not propagate. The midpack of the slab consists of snow that fell the first week and a half of December, and is 4 finger hard towards the top to pencil hard towards the bottom. The bottom of the snowpack consists mostly of 4 finger to 4 finger + hard facets, with depth hoar up to 4mm found in a snowpit dug on a north-northwest facing slope. This basal layer ranged from 10cm on a southeast facing slope to 45cm on a north-northwest facing slope. During our time in the field, we experienced no whumpfs or cracks. We traveled in some wind affected terrain on south and southwest aspects in a open meadow, but it did not amount to a wind slab. While we didn't travel in steep enough terrain to observe or trigger loose dry sluffs, the top 20cm of snow from the Christmas storm lacks much cohesion making it seem as though loose dry avalanches could be a concern in steeper terrain.
Avalanche
I did not observe any avalanches.