Vail & Summit County
SnowpackAndrew McWilliams · Mar 7, 2024 · Vail & Summit County
Weather
Broken skies with temperatures near freezing and light snowfall that didn't accumulate while I was in the field.
Snowpack
On the northwest slope where I dug, I found the early February (2/2) weak layer buried about 70cm below the surface. This layer had propagating results in Extended Column Tests (ECTs) after taps from the elbow and blows from the shoulder. I did not observe any reactive weak layers above this level, but there was a recent dust layer deposited at the beginning of March (3/3) with facets beneath it. This faceted layer was above a dense, slab of snow from late February that's resting on the 2/2 weak layer. The avalanche from the end of February on a southeast-facing slope likely ran on a layer of facets below a crust that was formed near the end of that month and not on the 2/2 weak layer. An ECT in the crown had a propagating result after one tap from the elbow on this weak layer. This will be a layer to watch moving forward on east and southeast-facing slopes. I haven't observed this layer on northerly-facing slopes. The 2/2 weak layer was present, but not reactive in this snowpit. The snow from January had vertical ice bodies in the slab, suggesting that future issues will be at or above the 2/2 weak layer. While I was investigating the crown, a very small Wet Loose avalanche ran on the same slope. Although the broken skies were limiting sun-affect, warm temperatures and cloud cover created a "greenhouse" effect which likely caused the small slide within a thin layer of loose surface snow.