Blowing Snow and Developing Wind Slabs on Lincoln Ridge

Rain changed to snow at about 6400 ft as we drove up Yuba Pass. We found about an inch of new snow at the trailhead at 11:30 am. The new snow rested on top of old snow surfaces that remained moist. The bonding between the new and old snow seemed good. As we climbed up Lincoln Ridge, the weather varied from light snow showers with some sun peeking through the clouds to intense snow showers. At times snowfall rates seemed close to 1 in/hr. By the time we got close to the ridge, 2 to 3 inches of new snow had accumulated in sheltered areas. We stopped below the ridge and dug a quick pit to look at the Feb 14th facets. They were still loose but seemed to be gaining strength. We also put on an extra layer at this break because we could see and hear the wind roaring along the ridge above us. 

We moved up to the ridgeline where the wind was blowing snow onto leeward slopes. We could see small cornices forming and signs of developing wind slabs. Even though only 2-3 inches of new snow had fallen the wind slabs were already 6+ inches deep near the ridges. These wind slabs did not extend very far from the ridges yet, but we expected them to keep growing since more wind and snow was forecast. Ski kicks triggered cracking in the small cornices, but when the cornice pieces dropped onto the slopes below they did not cause any wind slab failures. Ski cuts on one wind-loaded test slope also did not produce any cracking. A ski kick above that ski cut did crack the developing wind slab where it was undercut.