The shore of Lake Michigan was the scene of an ominous vision unfolding in the sky, as seen in the video. Bemused beach-goers watched as a tubular cloud rolled in from the horizon. The cloud was a roll cloud, a type of arcus cloud formed when sinking cold air causes warm air to rise, condense, and form clouds. This cloud phenomenon often appears over large bodies of water. As you can see in the video, roll clouds can manifest in a matter of minutes and will continue on their path until dissipating.
While they look scary, roll clouds are harmless — although they do sometimes coincide with storms. This particular roll cloud was accompanied by 30-mph gusts of wind, a drop in humidity, and a 1-degree drop in temperature.
Catch the eye-opening footage from one of the largest lakes in the United States in the video below.
Roll clouds are just one of the many weird weather phenomena caused when unusual wind activity occurs. Check out this video of storm clouds captured over Lincoln, Nebraska.Whizzco