Green River Canyon

Toured out to the Four Pines/Green River area from JHMR. Gusty winds were redistributing snow and forming shallow (3-6”) pockets of wind slab on leeward features above 9,000’. For the most part, these wind slabs were sluggish and not very reactive to human triggering. However, we did trigger one small (D1) wind slab on a steep, wind-loaded convexity at 9,100’ in Green River Canyon. The slide moved slowly and was stubborn to initiate. We did not observe any other recent avalanches.

Snow surfaces were a mix of dense wind pressed snow, punchy wind board, and some settled powder in sheltered locations. A temperature/rain crust exists below 8,000’.

Snow depths above 9,000’ are sitting around 1-2 meters (3.5-6 ft) south of JHMR. We dug at the top of Drew’s Slide in a wind-loaded spot (NE at 9,800’). Here, ~130cm of consolidated slab from the recent two weeks of stormy weather is sitting above 45cm of facets that formed in November and early December. The facets at this interface were 1mm in size, dry, but showing signs of rounding.

An Extended Column Test (ECT) resulted in several fractures, but no propagation, in the top 60cm of the snowpack. The fractures occurred on thin (<1cm), relatively soft layers of decomposing snow crystals that formed as a result of shifting temps/atmospheric conditions during the recent storm cycle (12/26–1/3). These interfaces have gained notable strength over the past week.