The ratio of snow to water

If you ever have ever watched the weather report during a snowstorm or talked to an old man in a pub you may have heard one or the other saying that the 10 inches of snow outside are the same as 1 inch of water. The comparison is made every time a little bit of snow hits the ground. But is it true?

The answer is a little more complicated than a simple yes or no but for those of you who want the quick answer, it is sometimes. In reality, the relationship between snow and water is not a given rule, it depends on the consistency of the snow that is falling. 

If the rain is falling when the temperature is -1 degrees celsius than one inch of rain would fall as ten inches of snow. However, if the temperatures are higher or lower than that the snow to rain ratio will change considerably. If the temperature fell to -4 then the ratio would be closer to 15 to 1. If the temperature increased it would be closer to 5 to 1. 

Actually, this is how most weather professionals work out who much snowfall there will in a given snowstorm. They are able to look at the temperature and overall weather patterns and make an estimate of what will happen. 

So if anyone ever throws out the 10-1 ratio again trying to look intelligent you can quickly shut them down. Tell them that it depends on the temperature at the time of the snowfall and quickly put them in their place. However when you are winning arguments about the weather ratios, maybe take a step back and wonder if there are more important arguments to win. Although we know too well that in the pub, every little win counts.