Snow drift equation: This is not perfect and works well for snow ratios of 10″ snow to 1″ water or (10:1) up to about 20:1, the wetter and drier snows throw it off as the wet snow will literally stick to the side of a building/tree and dry snow drifts very easily and is too conservative… Long story short: [(Avg wind gusts/10) X Snow (inches) = Avg drift]. For example: Avg winds gusts = 30mph, 6″ expected snow total equals an expected average drift of 18″, 30/10 = 3 X 6 = 18. It is crude and simple but it’s pretty darn good for an estimate if you are plowing snow in Colorado!