A wall cloud is the parent to a tornado. It's the rotating part of a thunderstorm that squeezes down a fast-spinning tornado, like an ice-skater pulling himself into a faster and faster spin.
The National Weather Service said that "rotating wall clouds usually develop before strong or violent tornadoes, by anywhere from a few minutes up to nearly an hour."
Downpours and locally severe thunderstorms over the Central states will not only foil holiday weekend activities, but will also put some lives at risk.
A few days after a chilly storm departs the Northeast, warm weather will make a strong comeback in parts of the Midwest and the East later next week.
The storm responsible for the wind, cold, rain and snow in the Northeast Friday and Saturday will slowly ease up for the balance of the holiday weekend.
During Sunday's race, the skies will be variably cloudy with the risk of a few showers.
"This pup was literally singing when he saw his family," Michelle Karolicki, relocation program manager of the Central Oklahoma Humane Society, said about a reunion that took place on Thursday.
Another plunge of chilly air will set the stage for the risk of a frost and freeze centered Michigan, Ohio, West Virginia and other nearby states this weekend.
Tornado swarm in Iowa, Illinois and Michigan; 74 killed.
Iowa City, IA (1859)
Waterspout; 8 killed, one child was taken up, carried 500 yards and thrown in a slough but survived.
New York City (1861)
Snow was reported.