How much water is in snow?
We all know you need moisture for snow but just how much moisture is in snow? It all depends on the storm, and the track. Where is the moisture source for a particular storm?
Storms that come from the Midwest or the Great Lakes will typically have less moisture. While storms that come from the south or ones that are able to tap into moisture from the Gulf of Mexico or the Atlantic ocean will have much more liquid content. We would classify snow in terms of wet or dry snow. Dry snow will have much less water content but can accumulate greater due to colder temperatures. Dry snow is the fluffier snow.
Wet snow has much more water content and is heavier. Its harder to shovel and can be much more slushy.
So when it comes to determining if snow is wet or dry, we look at the temperature. We can use an average of a 10:1 ratio. Meaning for every 1″ of liquid, that would equate to 10″ of snow. Snow doesn’t always fall this perfect and honestly, we rarely see the 10:1 “normal” ratio.
Now the ‘warmer’ the temperature, above freezing the wetter the snow. That gives us what we call a lower snow ratio. So we can see that ratio lower than 10. Sometimes a 3:1 ratio. For every 1″ of liquid, that would equate to 3″ of snow.
A dry snow is going to happen with colder temperatures. The colder it is the drier the snow and the more the snow can accumulate. This is our ‘fluffy’ kind of snow. You would also see the drier snow or high snow ratio our west across the Rocky Mountain region.
Dry and wet snow has different weights because of the difference in water content. Wet snow is much heavier and in heavy, wet snow storms this is when you have the risk of roof collapses.
High snow pack with either rapid snow melt or rain can lead to flooding issues. This happened after the January blizzard of 1996
Copyright 2021 WHSV. All rights reserved.