Pea soup for the whole day. Very brief am snow showers led to a trace of new snow. High humidity and light drizzle made the top few cm's of the snowpack heavy, almost moist. Nearly all day the winds were calm but moderate westerly gusts arrived as we returned to Heather Meadows early afternoon. Due to the heavy snow surface no snow was transporting with the wind.
One of my goals was to map surface hoar before the incoming storm. I found 3-4mm crystals at the bottom of Swift Creek on the surface, but they were clumped together and breaking down due to the moistening surface. I also found 3mm surface hoar near the top of Huntoon Point at about 1000am, buried under a trace of new snow from the morning. At that time the snow conditions at that elevation were dry. When we dropped down to about 4700ft the heaviness/moistness of the snow surface became very noticeable. This moistness increased as the day continued. I did not find any well developed or reactive wind slabs in the upper portions of the snowpack where we traveled. We were unable to trigger any avalanches. Very small loose wet avalanches were visible on the SW facing aspect of Swift Creek from yesterday 12/20 (photo). As we approached via that aspect in the morning, snow was still mainly lower density and dry but as we dropped towards the bottom, we began finding more surfaces on steep direct south aspects with a very thin sun crust- mainly on one side of each of the small drainages- from yesterday.