Silver Peak

Today, we returned to Silver Peak to investigate how the old, weak layers respond to the recent snow and whether wind slabs remained reactive. The air and ground felt moist when we stepped out of the truck at about 6700 ft. Almost no snow existed here, so we put our skis on our packs and started hiking uphill. At ~7300 ft, consistent snow about 4-6 inches deep allowed us to switch to skinning. This shallow snow was wet but supportable. Coverage improved with elevation, and by 7600 ft, most N-NE aspects had between 8 and 16 inches of supportable snow on them.

In the sheltered terrain below the ridge, 4-5 inches of fresh snow rested on a thin layer of weak snow (graupel and facets) above a rain crust with a mix of crusts and soft, sugary snow below that. In areas exposed to wind scouring, the new snow sat directly on the rain crust in many places. The warmer weather and some rain had made the recent snow heavier and more cohesive (aka more slab-like). When we dug into the snowpack at 7400 ft, 7700 ft, and 8200 ft on N-NE aspects, we found that the old, weak snow below the new snow had also become moist. It now clumps together when squeezed and shows signs of increased bonding. Our tests at these elevations did not indicate that the new snow has yet overloaded the old, weak layers (ECTN @ 7400 ft, RB6 @ 7700 ft, and ECTN on the old, weak snow @ 8200 ft). We did trigger some minor cracking below our skis if we stepped above our skin track. 

As for the wind slabs, we found evidence of shifting winds, with some areas on N-NE aspects scoured back to crusts and other places loaded with up to 2 ft of wind-drifted snow. We dug into one wind-loaded NNE-facing test slope at ~ 8200 ft and got unstable ECT results on a density change 6-8 inches below the surface in the wind-loaded snow (ECTP 21).

Some minor cracking occurred under our skis. Cracks only happened above undercut areas of snow and did not travel far away from the tips or tails of our skis.