What phenomenon is characterized by a rotating column of air not touching the surface?

The phenomenon characterized by a rotating column of air that does not make contact with the surface is a funnel cloud. A funnel cloud is typically associated with severe thunderstorms and forms when warm, moist air rises and cools, resulting in condensation, which creates a visible cloud that is shaped like a funnel.

Funnel clouds can develop into tornadoes if they extend downward and make contact with the surface, but as long as they remain suspended in the air and do not connect with the ground, they are classified as funnel clouds. This distinction is essential in meteorology, as it helps in predicting the potential for tornado formation.

In contrast, a waterspout is similar but occurs over a body of water, and tornadoes are defined as rotating columns of air that have made contact with both the cloud base and the surface. Vertical visibility pertains to the ability to see vertically through an obscure air layer and does not describe a rotating column of air.