Ok i understand what your saying! But i always thought that snow was created by warm air where the rain clouds are up high and when the rain falls through the colder air on its way down it turns to snow?? As you can see i am no weather guy!
J Curtis is correct with his conversion numbers, but the local T.V. weather guesser here (who is a snow geek) said that in coastal area's the rate can be as low as 4" per inch of water and in the mountains as much as 22" per inch.
In the Blizzard of 97 around here it worked out to about 5" of water = 25"s of snow. That was some heavy pushin!
Snow is formed when an moisture laden air developes an ice crystal on a piece of dust/dirt. It keeps adding weight till it falls to earth. The air needs to be cold all the way to the clouds. If the air layer is cold from ground to clouds you will get snow.
Warm air is lighter than cold air and will ride up and over it, so if the clouds are warm and the ground cold, you will get freezing rain, and in between the two extremes you have sleet.
That is why it can be 20 degrees outside and raining.
However, many times the air at the ground will be above 32 degrees and yet it still snows. This is because the clouds are cold, when the snow starts, it will actually cool the atmosphere on its way down. Winter weather is very cool stuff,(pun intended)
and very complex, that is why it is so difficult to forecast.
Add elevation into the fray and the moisture content per inch of snow really changes. On the up slope of mountains, as the air rises, it sqeezes the moisture right out. Where as at sea level the air is much more dense, and thus you have a higher moisture content. I have actually seen water running out of the snow, cause it had so much water in it. When it does that, the snow has a blue color to it.
Throw in some ocean influence near where I live and all bets are off.
just read this the other day in a snow business supplement in lawn & landscape:
"...the average ratio is 10" of snow to 1" of water...fluffy snow can have a ratio in the neighborhood of 30" of snow to 1" of water...heavy, sticky snow can [have a ratio of] 5" of snow to 1" of water..."
who knew???...i always heard the 10:1 one thing?!?!?!