19th century illustration of a waterspout, an intense columnar vortex (usually appearing as a funnel-shaped cloud) that occurs over a body of water. They are connected to a towering cumuliform cloud or a cumulonimbus cloud. Waterspouts exist on a microscale, where their environment is less than two kilometers in width. The cloud from which they develop can be as innocuous as a moderate cumulus, or as great as a supercell. While some waterspouts are strong and tornadic in nature, most are much weaker and caused by different atmospheric dynamics. More than one waterspout can occur in the same vicinity at the same time. As many as nine simultaneous waterspouts have been reported on Lake Michigan.