Shifting Winds on Judah

Driving up to Donner Summit the clouds blowing across the sky from the W and SW foreshadowed the very windy conditions I would encounter on any exposed ridgelines.

As soon as I left the parking lot and started skinning up Mt. Judah, I found sometimes firm and sometimes breakable sun crusts with soft snow below them on sheltered westerly aspects (photo 4). The sheltered northerly aspects still had patches of soft snow. I filed this information away for the descent and kept skinning up the hill.

Once the terrain became more exposed, the evidence of wind-affected snow was everywhere. Sastrugi, blowing snow, wind-scoured firm icy crusts, firm wind-packed hollow sounding snow, softer newly drifted snow, and other wind effects were widespread (photo 5-7). I gained the ridgeline and the winds increased and were transporting snow back over to the N-NE-E aspects. I found a small wind-loaded test slope and was able to trigger some small cracking in a newly formed wind slab that measured about 4 inches deep (photo 3). Below this new wind slab, the snow felt firm and wind packed. Probing with my pole indicated that there was still a softer layer under this older firm wind slab. I pulled out my shovel and did some quick snowpit tests. My tests yielded unstable results as the older firm wind slab failed on the layer of lower density snow about 12-14 inches below the surface (ECTP's - see photos 1 &2). As I continued up to the summit, I saw very large overhanging cornices on Wildflower Ridge (photo 7) and on the summit ridge of Mt. Judah. Wind speeds and snow transport continued to increase all the way to the top of Judah. At the summit, I could see the weather system coming from the west (photo 8). 

On the descent, I sought out low angle sheltered terrain and avoided any wind-affected areas. In the most sheltered areas, some patches of soft snow still existed on N aspects.