An intense columnar vor (not necessarily containing a funnel-shaped cloud) of small horizontal extent, over water. Typical visible vor diameters are of the order of 33 ft (10 m), but a few large waterspouts may exceed 330 ft (100 m) across. In the case of Florida waterspouts, only rarely does the visible funnel extend from parent cloudbase to sea surface. Like the tornado, most of the visible funnel is condensate. Therefore, the extension of the funnel cloud downward depends upon the distribution of ambient water vapor, ambient temperature, and pressure drop due to the vor circulation strength. These vortices are most frequently observed during the warm season in the oceanic tropics and subtropics.

All waterspouts undergo a regular life cycle composed of five discrete but overlapping stages. (1) The dark-spot stage signifies a complete vor column extending from cloud-base to sea surface. (2) The spiral-pattern stage is characterized by development of alternating dark- and light-colored bands spiraling around the dark spot on the sea surface. (3) The spray ring (incipient spray vor) stage is characterized by a concentrated spray ring around the dark spot, with a lengthening funnel cloud above. (4) The mature waterspout stage is characterized by a spray vor of maximum intensity and organization. (5) The decay stage occurs when the waterspout dissipates (often abruptly).

Waterspouts and tornadoes are qualitatively similar, differing only in certain quantitative aspects: tornadoes are usually more intense, move faster, and have longer lifetimes—especially maxi-tornadoes. Tornadoes are associated with intense, baroclinic (frontal), synoptic-scale disturbances with attendant strong vertical wind shear, while waterspouts are associated with weak, quasibarotropic disturbances (weak thermal gradients) and consequent weak vertical wind shear. Tornado Wind