Showers in the mid-Atlantic states on Monday brought some roll clouds to parts of Virginia and Maryland.
According to AccuWeather.com Expert Senior Meteorologist Henry Margusity, roll clouds are the result of an outflow of cold air after a bout of rain.
"A shower or thunderstorm forms, and then cool air follows behind it," Margusity said. "As the cool air rushes out, warm air moves in on top of it."
Condensation along the meeting point between the cool air and the warm air result in these roll clouds. Take a look at these roll clouds that were seen on Sept. 16.