Sky: Clear
Precip.: None
Temp.: -15C at highway in the morning, -8C at pit location midday.
Wind: Mostly calm, occasionally light from the NW.
Observation: Summit
Location: Colorado Ridge
Toured up from highway to treeline. Found a wind slab avalanche that looked to be a week or two old on a small convexity right at the top edge of treeline. Dug a pit on the immediately adjacent to the right flank, same aspect, slightly shallower slope.
Weather
Snow surface
Surface hoar in open meadows below 2,000'. This surface hoar appeared to be knocked down above 2,000', however by that point we were no longer on shaded aspects. Widespread wind effects around treeline and above. Did not see an obvious pattern of consistent scouring / deposition across similar aspects
Snowpack
Below treeline, quick hand-pits showed shallow snowpack with widespread surface hoar sitting on approx 12cm of faceting snow over a 4cm crust. Beneath that, another 15-20cm of rotting snow.
At treeline and above, significant wind effects. Found an old (1-2 weeks) small wind slab avalanche. Slope angle 37-38 degrees, crown approx. 30cm, width approx. 40m, that ran a short ways and deposited debris on a little bench immediately below the convexity.
Pit revealed a layer of soft snow approx. 30cm deep that appears to be the same layer the adjacent avalanche failed on. Unable to clearly identify grain form of this layer.
Did not have a snow saw, so isolating columns for instability test was challenging in the very hard old wind deposited snow. Test result is suspect at best.
Pit Profile
Old wind slab avalanche debris. Crown is just out of frame on the right.
Pit photo. HS 185cm