Sawatch

Avalanche

John Mackinnon · Dec 29, 2019 · Sawatch

Weather

Mostly cloudy with high thin clouds, light NW winds and bitterly cold. Measured an air temperature of -2 F at 3 pm at 11,500 ft.

Snowpack

Our group dug several snow profiles on an east aspect at treeline to investigate the Persistent Slab avalanche problem on the East Side of Leadville. Average snow height of about 80 cm. Bottom 30 cm of snowpack consisted of fist hard depth hoar. What's left of a "mid-pack" slab is slowly faceting away. There was about 5 cm of recently wind-drifted snow on top of the snowpack. Despite the weak and mostly faceted snowpack, we did get repeatable sudden collapses in the depth hoar layer during compression tests and we also got a positive result in an ECT in the depth hoar (ECTP 25 x 1). We did observe some cracking in the upper snowpack in exposed areas near and below TL where northerly winds had drifted recent storm snow into very shallow slabs.

Avalanche

I think I saw some debris on a southwest aspect above TL on Little Ellen Hill. It was hard to tell in the flat light but it looked like it could have been a very shallow wind slab on the steeper roll above Alps Gulch.