#MEwx Calculating snow depth to inches of rainfall

Snow to Water Ratios

The amount of snow from a storm can look impressive when it covers your house

and cars, but if you melted the snow you would discover that very little water is actually

involved. The 'snow to ice ratio' or Snow Ratio expresses how much volume of snow

you get for a given volume of water. Typically a ratio of 10:1 (ten to one) means that

every 10 inches of snowfall equals one inch of liquid water.

For example:

Problem 1 - During a winter storm called 'Snowmageddon' in 2010, the Washington

DC region received about 24 inches of snow fall. If this was dry, uncompacted snow,

about how many inches of rain would this equal if the Snow Ratio was 10:1 ?

 

Answer: 24 inches of snow x (1 inch water/10 inches of snow) = 2.4 inches of

 

Problem 2 - The Snow Ratio depends on the temperature of the air as shown in the

table below:

Temp (F) 30o

 

25o

 

18o

 

12o

 

5

 

o

 

-10o

 

Ratio 10:1 15:1 20:1 30:1 40:1 50:1

 

If 30 inches of snow fell in Calgary, Alberta at 18o

 

F, and 25 inches of snow fell in

 

Denver, Colorado where the temperature was 25o

 

F, at which location would the most

water have fallen?Unlabeled graphicSpace Math http://spacemath.gsfc.nasa.gov

 

Answer - In Alberta, the Snow Ratio for 18o

F is 20:1 and in Denver at 25o

F it is

15:1.

The amount of water that fell in Alberta is then 30 inches of snow x (1 inch water/20

inches snow) = 1.5 inches of water. In Denver it is 25 inches of snow x (1 inch

water/15 inches snow) = 1.7 inches of water. So more water fell in Denver, even

though there was less snow on the ground!

 

You all got that, right? Any questions?