Footage of the unusual cloud formation in Ohio is going viral on Reddit.
“I was under the impression it was a tsunami I’ve never seen clouds like this before,” user fooman141 captioned the video.
We believe it is a roll cloud — a low, horizontal, tube-shaped, and relatively rare type of arcus cloud. Roll clouds usually appear to be “rolling” about a horizontal axis.
The roll cloud is not attached to its parent thunderstorm. It’s associated with a gust front or outflow boundary out ahead of the thunderstorm.
These clouds form when warm, moist air is lifted by rain-cooled air moving underneath it caused by the storm’s downdraft or gust front. When the warm, moist air is lifted it condenses and forms the cloud.
“I saw clouds like this once, while driving. Came around a bend and slammed on my brakes (like everyone else) because it legitimately looked like a huge wave was about to crash down on us. It was incredible. Really beautiful after I understood I wasn’t about to die,” one user commented.