SIOUX FALLS, S.D. (KELO) — A large part of KELOLAND woke up to several inches of wet, heavy, and at times outright slushy snow.
This kind of snow can also be called “Heart Attack Snow” since it requires extra effort to move when shoveling. The increased weight comes from the higher liquid water content of this snow, something that can be estimated by using the snow ratio.
The old rule of thumb is a 10 to 1 ratio, meaning that if you melt down 10 inches of snow you’ll get an inch of water.
In the real world, such a ratio doesn’t always happen due to several factors, including the temperature within the cloud. Temperatures closer to freezing will allow for wetter snow, thus lowering the ratio, while colder temperatures yield a higher ratio.
The number of ice crystals within a cloud can also play a factor. More ice crystals mean a higher ratio of water compared to a cloud with more super-cooled water.
All of this can tie into a third factor: Our air temperature. More intense cold tends to help high-ratio snow develop compared to temperatures near freezing, since a colder air mass is inherently drier.
As we get closer to and ultimately get into the spring season, any late season snow will more likely skew toward the low-ratio, high moisture variety. Keep that in mind as you start shoveling.