What Is a Waterspout?

Waterspouts are whirling columns of air and mist that form most frequently during warm seasons over oceans, harbors, and lakes. They're often called "tornadoes over water," but not all waterspouts are true tornadoes. Of the two types of waterspouts—fair weather and tornadic—only tornadic waterspouts are actually tornadoes.

The lower Florida Keys report more waterspout activity than any other location in the world, and Florida is considered to be the waterspout capital of the U.S. 

The words fair weather and waterspout may seem like a contradiction, but most waterspouts form during periods of mild to warm sunny weather.  

This type of waterspout initially forms over water due to warm temperatures in the lower atmosphere that combine with high humidity. Fair weather waterspouts are generally not as dangerous and are far more common than tornadic waterspouts. In contrast to an ordinary tornado which develops downward from a thunderstorm, a fair weather waterspout develops on the water's surface then makes its way upward into the atmosphere. 

First, a dark spot forms on the water's surface. The spot gradually moves into a spiral pattern, then a spray ring forms. A condensation funnel develops before the waterspout eventually dissipates and spins out. 

Waterspouts of this type are often short-lived, lasting less than 15 to 20 minutes. They also tend to be quite weak, rarely rating higher than an EF0 on the Enhanced Fujita Scale. Another characteristic of fair weather waterspouts is that multiple vortices or funnels often form in the same area at one time.

Whenever a fair weather waterspout moves over land it is called a landspout. However, fair weather waterspouts often unravel and dissipate as they approach land. 

Tornadic waterspouts are tornadoes that form over water or move from land to water. They form under the same severe weather conditions as ordinary tornadoes—that is, they are vertical columns of rotating air that extend from cumulonimbus or severe thunderstorm clouds down to the ground. Also like ordinary tornadoes, they have high winds, large hail, frequent lightning, and can be fairly destructive.

For you snow lovers, there actually is such a thing as a winter waterspout—a waterspout that occurs in the winter season beneath the base of snow squalls. Called "snowspouts," "ice devils," or "snownadoes," they are extremely rare—so rare, in fact, that only a handful of photos of them exist.

Boaters and people who live near larger bodies of water should take waterspout watches and warnings very seriously, even those for fair weather waterspouts. A watch simply means that current conditions might produce a waterspout, whereas a warning is issued when the National Weather Service has detected waterspout activity in the area.

Be sure to keep your distance. Never move in for a closer look because you probably won't be able to tell what kind of waterspout it is and a tornadic waterspout can be as dangerous as a tornado. If you're out on the water when a waterspout forms, move away from it by traveling at a 90-degree angle from its movement.