A small, narrow funnel cloud was observed near Edmore, Michigan just after 7 pm on Wednesday, June 2nd. The cloud did not reach the ground and no damage was reported. These funnel clouds occur when a rapidly developing updraft associated with a cumulus cloud is able to tilt a small horizontal circulation into the vertical and stretch it. The stretching makes the circulation spin faster as it becomes more narrow. This is due to the effect of conservation of angular momentum, the same process that causes a spinning figure skater to spin faster when the arms are drawn inward. These funnel clouds can persist for several minutes, but typically do not reach the ground. They are sometimes called "cold air funnels" since they frequently occur in the moist, unstable air just after a cold front moves through, in a region of turbulence and small scale circulations that can be tilted and stretched by vigorous updrafts.
The funnel cloud, photographed at 708 pm.
Credit: Andrea Armstrong