East Winds on Andesite Peak

While driving up to Donner Summit I could see a few small clouds racing across the sky driven by the cold E/NE winds. I started up towards Andesite and one of the people I talked to described strong and gusty winds on the ridge. I decided to gather a little more information in the sheltered below-treeline terrain to see if maybe the winds would decrease before I made it up into more exposed terrain. I found some surface hoar on the snow surface in open meadows below treeline. When I dug into the snowpack in one of these areas, I also found a thin layer of surface hoar buried about 4 inches (10cm) that looked like it was decomposing. Below that, the snowpack was more consolidated. Snowpit tests targeting the surface hoar layer did not produce unstable results, but the snow above the surface hoar was also not very slab-like.

After I explored the snowpack below treeline, I went up to the ridge and found strong E/NE winds, as expected. The strong winds had heavily scoured the E-facing slopes. The W and NW-facing slopes still held soft cold snow. Along the ridge, the E side was scoured back to rock in some places, and small drifts of wind-blown snow had formed on the W side of the ridge. These drifts were firm, and kicking them only produced cracks if I undercut the drift. They also did not extend very far from the ridge.