What is the Snow to Rain Equivalent? - WAOW - Newsline 9, Wausau News, Weather, Sports

What is the Snow to Rain Equivalent?

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Someone called in the other day to ask me what the snow to rain equivalent is.  In meteorological terms we call this the snow to liquid equivalent.   In other words , when you melt the snow down how much does it equal in liquid precip.  With all the rain that we have seen it is a really good question and not one that can be answered with a simple 10 inches of snow equals one inch of rain (although that is the average!)

Once we get below freezing snow will fall but the temperature that we are at depends on what kind of snow we will see.  If we are near freezing( around 32 Fahrenheit) we will see wet snow which consists of greatly more water then when the temperature is cooler.  ( Remember the amount of moisture in the air, the dew point, can never be greater than the temperature).  So if you have heavy wet snow falling you will usually see large snowflakes.  Now if the ground is above freezing the snow will likely melt when it hits.  If this happens then there will likely be no accumulations. BUT, if the ground is below freezing it will likely pile up!  This snow is usually sticky and will produce less than the average snow to rain equivalent, normally ranging around 5 inches to 1 inch of rain.  So this type of snow produces more liquid equivalent than the normal.

On the other hand if we have dry snow we could see ratios of 10, 15 even up to 30 inches of snow to equal one inch of rain.  This is because the dry snow will be made up of very little water, meaning it will be less dense than its counterpart.  These snow flakes actually have air pockets in between the snow crystals.  This snow is not as sticky and can easily be blown around. So in these circumstances we could see over a foot or more equal only one inch of liquid or rain.

Till next time! Meteorologist Kristen Connolly         

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