WRAL WeatherCenter Blog

Several years ago, we had a rare 23" snowfall here in Apex. How much rainfall in inches would that storm be equivalent to?

Posted November 18, 2007 10:10 a.m. EST

MIKE MOSS SAYS:      David,    That would be the snowstorm of 24-25 January 2000 that you're referring to. The snow totals varied somewhat across the region of course (see attached map), but at the Raleigh-Durham airport those two days combined for a storm total snowfall of 20.3 inches. The National Climatic Data Center recorded the liquid equivalent precipitation for that event as 2.37 inches, although the first 2-4 hundredths of an inch or so fell as light rain before changing to snow.

Those numbers result in a ratio of snow to liquid water of about 8.6 to 1. This is not an atypical ratio for our area, where the ratio can range from as low as 3-4 inches of snow per inch of liquid to as high as 15-20 inches of snow per inch of liquid, depending on the particulars of storm structure, soil temperature and vertical profiles of  temperature and moisture through the lower and mid levels of the troposphere.