On June 23, a thunderstorm watch was forecast for much of West Virginia, a common summer occurrence in the state. What the forecasters did not anticipate was a weather phenomenon called “training,” which occurs when a series of thunderstorms line up in succession behind one another in the same location.

At the end of the storms, about 10 in. of rain fell on the area. To appreciate how much rain that is, consider 1 in. of rain equals about 13 in. of snow, according to the National Severe Storms Laboratory, making this storm equivalent to more than 10 ft. of snow.