Video: Watch A Breathtaking Roll Cloud Turn Over Chicago On Tuesday

By Stephen Gossett in News on Aug 31, 2016 2:37PM

So-called roll clouds are “relatively rare,” according to the National Weather Service, but Chicagoans got an up-close-and-personal look at the breathtaking phenomenon on Tuesday.

The NWS defines a roll cloud as a “low, horizontal, tube-shaped arcus cloud associated with a thunderstorm gust front (or sometimes with a cold front).” The one spotted in Chicago would appear to the be latter, with a mixture of warm and cold air creating the roll effect.

"Roll clouds usually appear to be "rolling" about a horizontal axis,” the NWS adds, which can be seen in dramatic detail in the video—shot by art consultant Amy King at North Avenue Beach and posted by art/design blog Colossal—and photos below.

Roll clouds were also spotted as far south as Urbana, Illinois.

[H/T ABC7]