Snow Science

Just how much water do we actually get from winter snow storms?

After a huge blizzard, you may hear that your area got 30 inches of snow. But how much water does this snow actually produce? This is a great opportunity for young scientists to figure out the snow to liquid equivalent conversion… and to make a few snowangels at the same time!

Experiment Materials

  • Rain Gauge
  • Ruler
  • Snow

Experiment

1

Before the snow begins, set up your rain gauge in an area where it will be able to freely catch the falling snow without interference from surrounding objects.

2

After a certain time interval, or after the snow has stopped, bring the rain gauge inside and allow the snow to melt.

3

Using either a ruler or the marked measurements on the rain gauge, measure how much water there is.  This number is about the actual amount of water that your community gained from the snow.

How Does It Work

People often think of snowfall in terms of how many inches of snow accumulated after a snowfall event. Anyone who lives in an area that often receives snow knows that different snowfall events can produce snow of different densities. There can be wet, heavy snow or the very dry, powdery variety.

Meteorologists and hydrologists tend to express snowfall amounts in terms of “liquid water equivalent,” which is simply the amount of liquid water that you would get if you were to melt the snow. Another way of thinking about it is that the liquid water equivalent is how much rain would fall if it were warm enough for the snow to fall as liquid, instead of frozen precipitation.

The exact formula to calculate liquid water equivalent is the snow depth multiplied by the snow water density. A commonly used rule of thumb is that every 10 inches of snow that falls is equivalent to 1 inch of liquid water. This “10-to-1 rule” doesn’t always apply, however, as the actual liquid water equivalent of snowfall varies quite a bit, depending on meteorological conditions and geographic location.

Days like this make you hungry…for snow ice cream! To make your own, gather a large bowl of clean snow.   Stir in the following ingredients:

  • 1/2 cup sugar
  • 1 can evaporated milk
  • 1 tsp vanilla

You may need to adjust the amounts of each ingredient to fit your own preferences for taste and texture. Eat and enjoy!