Not all snow is made the same: Snow ratios

Not all snow is made the same – some of it is light and fluffy like cotton balls, and some has the consistency of mashed potatoes.

Snow maps are very popular, with bright colors indicating varying snow amounts across a given area… but many of those models only operate on a 1:10 snow ratio.

That is to say 1 inch of liquid water in the environment converted to snow should equal 10 inches.

But most cases of snow have varying snow ratios… such as 1:5… 1:20… or in some cases even 1:30 and 1:50!

A 1:5 ratio is considered a heavy, wet snow. 1 inch of water is only able to yield 5 inches of heavy, wet snow. This is usually when temperatures are hovering around 28°-32° with plenty of moisture around. These accumulations also tend to compress on themselves given the weight… so snow accumulations are usually a little less than forecasted despite the addition of moisture. This consistency is excellent for snowballs!

Sd Snow 1

From Erin Ward Schaffer

A 1:30 or 1:40 snow ratio means that even 0.10″ or 0.20″ of water could yield 8″-12″ inches of light, fluffy powder. This is where you get dendritic snowflakes… the beautiful six-sided crystal that forms all sorts of patterns. This is an excellent snow for skiing or snowboarding, and much easier to scoop off your sidewalk… (but also is easier for the wind to blow around). Although the snow amounts seem high… the water equivalent is usually low.

So if you’re looking for a drought-buster type of snowstorm…. look for low snow ratios and heavy, wet snow. The next time someone shows you a snow map… ask them…

What’s the snow ratio?

Categories: Local News, Weather Daily