Several signs of instability from Blue Lakes to Indian Valley

Snowpack tests were only a formality today, as a deep instability made itself known with whumpfing and shooting cracks throughout our ride. We started at the trailhead learning that a path on Hawkins Peak had avalanched to the ground, and was visible from the drive up Hwy 88. Near Border Ruffian, on our first trip off the groomed road, we experienced an obvious collapse and drop in the snowpack by an inch or two. This continued throughout our off-trail travels from Tamarack Junction to Indian Valley. Many times, we saw cracks away from us at the edge of the collapse, between the height of the snow that had collapsed and the snow that hadn't. 3x ECTs propagated on the Dec 11th facets, at various locations between 8000ft and 8400ft on shaded slopes with sparse tree cover.

Yesterday's thin rain crust was everywhere we traveled today, though our high point was only 8400ft. On sheltered slopes between 8000ft and 8400ft there was 6-8" of new snow. Any slope exposed to the wind held no new snow above the rain crust. Below 8000ft new snow totals were only 3-5". Mitt pits and hand shears indicated the snow just below and above this crust will be worth monitoring. Where the crust was exposed at the surface, the snow just below was especially weak. In many places, there were also two layers of graupel within the new snow that produced clean hand shears.

I could no longer identify the buried surface hoar layer that I could in the same areas last week. The Dec 25th interface was still an obvious stripe in the snowpack, but appeared to have gained strength since last week.

Pic 1: There's now enough supportable snow to ride off-trail from the location of this photo all the way to the Wilderness boundary at the base of Raymond Peak, in the background. Note the change in snow cover to the looker's left of Raymond (Monitor Pass).

Pic 2: Already signs of settlement in the new snow, but all indications today were that the Dec 11th layer is still weak.

Pic 3: Graupel on the surface throughout our travels, with surface hoar growing from the graupel on open terrain sheltered from the wind - observed both in the morning and upon our mid-afternoon departure.