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 Cloud literally rolling over Chicago earlier. Wow! pic.twitter.com/pVTfCKpzsk— Michael Piff (@Mike_PiFF03) August 31, 2016
Roll cloud over Chicago pic.twitter.com/J6KIHRA4ir— Jessyca Malina (@jessycamalina) August 30, 2016
Roll clouds were also spotted as far south as Urbana, Illinois.