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.
The taste of September across the north-central United States will give way to a resurgence of heat, steamy air and severe weather by midweek.
Much cooler air with temperatures more typical of mid- to late September will sweep across the Great Lakes and Northeast early this week.
Residents of the northeastern and midwestern United States should not get used to the September-like air pouring in early this week.
The recent April-like rainy stretch of weather will quickly get erased by a resurgence of sizzling heat in northeastern China this week.
Despite escaping the worst of newly-formed Hurricane Dora, southern Mexico will still face locally flooding downpours and rough seas into Monday.
Much of the southern United States dealing with the aftermath of Cindy will get a break from hot, humid and stormy conditions by the end of the weekend.