Chapter 2: "Cold pool"
Scientists used the term "Cold Pool" to describe this 'chapter' of the storm, it meant that a cold maritime flow came from the northwest over of the Gulf of Alaska (below left). This took place from February 14-17, 2019, producing 2.8 inches of snow water equivalent.
Comparted to the atmospheric river, the much colder air allowed more aerosols to infiltrate the cloud, decreasing drop size. This smaller water droplet size caused much smaller riming on crystals that came down.
(Rime - do you remember that word? It refers to the tiny water droplets that freeze onto the surface of a snow crystal or other surface.)
The Lake Tahoe and Reno areas both saw columns, needles and dendrites with small, opaque rime droplets (below center and right).