Click the link to read the article on the Steamboat Pilot & Today website (Dylan Anderson). Here’s an excerpt:
But what actually happened up in the clouds to drop this snow that many claim to be so special? Gannet Hallar, director of Storm Peak Laboratory at the top of Mount Werner and a professor with the University of Utah, said it starts with the snowflakes.
“If you have the perfect snowflake, which we tend to call a stellar dendrite, it has a lot of air and not so much water in its formation,” Hallar explained. “What allows for those types of snowflakes to form is both the temperature and the amount of water in the air as the snowflake forms within the cloud itself.” Snow often starts as dust, which then forms ice. As the ice builds outward, its shape is based on the amount of water and the temperature. Hallar said warmer temperatures allow for higher water content, while colder temperatures often bring lighter, drier snow.,,
Local meteorologist Mike Weissbluth said this relationship can be seen by looking at data from Storm Peak Lab from this week. At about 6 p.m. Monday, Dec. 12, as the storm front moved in, the temperature started dropping…Weissbluth said those low temperatures, combined with the right amount of moisture, put Steamboat in the center of the dendritic growth zone, which allowed the flakes to quickly pile up a fresh blanket of low density snow. The snow’s density is lower because the bigger the dendrites, the looser the snow packs and the more air is mixed in. While snow elsewhere can have a 15% water content, the powder in Steamboat tends to be closer to 7%, Hallar said. Another key factor in Steamboat’s snow is the geographic location, right next to a large wall that is the Park Mountains. Hallar said this process of wringing moisture out of the clouds as they rise is called orographic lift, and puts Steamboat in prime powder position.