Vail & Summit County
AvalancheAndrew McWilliams Ryan Zarter · Mar 18, 2023 · Vail & Summit County
Weather
Below-zero temperatures warmed quickly with clear skies and calm winds. There was no precipitation.
Snowpack
We dug snowpits on a northeast and a southeast aspect. Most surfaces we traveled on were affected by the sun and recent warm temperatures. Only on northerly-facing slopes did we find softer snow near the surface. On the northeast-facing slope, the surface snow was composed of faceted grains from recent sunny days and cold, clear nights. Snowpit test results in Extended Column Tests (ECTs) were easy to moderate and non-propagating in the upper snowpack. The most concerning result was a hard, propagating result after nine taps from the shoulder at the interface with the depth hoar layer. Our pit may have been in a shallower area as we dug on the margins of the slope. However, it is good evidence that in a shallower area, you can still affect deeply buried weak layers. We descended southerly slopes where we found a supportable melt-freeze crust with some areas of faceted snow on the surface. While traveling across a small test slope, we noticed shootings cracks within the upper crust layer. In our snowpit on this slope, we got a result upon isolation in this layer while isolating our column for an ECT test. On this slope, the height of snow was about 180cm with the bottom meter of the snowpack composed mostly of rounded grains pencil to one-finger hard on the Hand Hardness Scale. We only dug down to 90cm above the ground. ECT results again had moderate non-propagating results in the upper snowpack associated with crust layers. On our egress, we noticed some old wet loose activity on southerly slopes in a steep, rocky area. These slides likely ran last week closer to the end of the last storm with warm temperatures.
Avalanche
A small loose dry sluff on a northerly aspect near treeline.