5 days Ago By Jesse Ritka
FARGO — Snow is on the mind this week but the type of snow can vary greatly with each snowstorm thanks to snow ratios. One of the more common emails we receive in the weather center is “if that rain were snow, how much would we have seen?”. The dynamics in the storm systems that bring rain are vastly different than the ones that bring snow, especially when it comes to how much moisture is in the air surrounding the storm system.
But moisture does play a factor in snowflake formation, the big flakes most of us think of when we hear the word snowflake form when there is more moisture available, often resulting in a wet snow. This is where snow ratios come into play and where some of the confusion about rain and snow may originate. Five inches of snow with a low snow ratio of 5:1 melts down to one inch of water, this is what makes it a heavy, wet snow since there is such a high amount of water in it, making it good for making snowballs, forts and snowmen since the water content is higher.
A 10:1 snow ratio is the standard, where 10 inches of snow melts down to one inch of water. Snow ratios often fall in this vicinity when temperatures are close to the freezing point at the surface, though many other factors can affect the snowflakes before then. The deeper into winter we get, the colder the average temperature becomes and that plays a pivotal role in the snow ratio.
Colder air holds less moisture so snow ratios are greater. 15 inches of snow melts down to 1” of liquid in a 15:1 ratio. This is dry snow and is great for making snow angels and makes for easy shoveling but also great for being blown around and often can lead to blizzard conditions if the wind is strong enough.
Even if it is not actively snowing the wind can easily whip up this dry snow and send it soaring into the sky to initiate a ground blizzard. And while we can get any type of snow at any point in the winter season, the wettest snows typically fall during the buffer months surrounding the heart of winter giving kids a short window to make Frosty and Olaf..
