What Is a Waterspout?

Waterspouts form over water bodies such as lakes, seas, and harbors.
Waterspouts form over water bodies such as lakes, seas, and harbors.

A waterspout is a whirling column of mist and air that forms over oceans, seas, lakes, and harbors especially during warm seasons. Although they are openly referred to as tornadoes, not all waterspouts are true tornadoes. There are two main types of waterspouts; tornadic and fair weather. The tornadic waterspout is an actual tornado. Florida is the waterspout capital of the United States, and the lower Florida Keys experience more waterspouts than any other place in the world.

Types of Waterspouts

Fair Weather Waterspout

Although the words waterspout and fair weather seem contradictory, most waterspouts form during warm, sunny, and mild weather. A fair weather waterspout forms over a water body when warm temperatures combined with high humidity in the lower atmosphere. They are more common and less dangerous than tornadic waterspouts. Unlike the ordinary tornado that spirals downwards from a thunderstorm, the fair weather watersports forms on the water surface then spiral upwards to the atmosphere. These waterspouts last for between 15 to 20 minutes. They are weak and unlikely to cause significant damage. Most fair weather waterspouts unravel before reaching land but are known as landspouts when they do.

Tornadic Waterspout

A tornadic waterspout is a true tornado and forms in the same manner as other tornadoes. It is more powerful and more likely to reach land than the fair weather waterspout. It forms as a vertical spiraling column of mist and air from severe thunderstorm clouds to a water body. Tornadic waterspouts are characterized by high winds, lightning, large hail, and destruction.

Winter Waterspouts

A winter waterspout/snowspout/ snownadoes forms during the winter beneath the base of snow squalls. Winter waterspouts are extremely rare and only a handful have been documented. They are formed when air moving across the water is extremely cold that steam rises from the surface.

Formation of Waterspouts

Both the Fair Weather and Tornadic waterspouts require extremely high levels of humidity and warm water temperature. A combination of these weather conditions is common in the Florida Keys, the east coast of Australia, and the islands of Greece. A waterspout undergoes 5 stages of formation. At the beginning stage of formation, a dark spot appears on the water surface when the spiraling column of wind reaches the water body. Next, light and dark bands form a spiral pattern from the dark spot. A spiral ring of sea spray known as a cascade is formed around the dark spot and contains an eye at the center typical of a hurricane. At this stage, a mature vortex develops. This is the most intense stage of the waterspout. It is visible from the water surface to the clouds overhead and appears to be funnel-shaped and surrounded by water vapor. The last stage is decay. After about 15 to 20 minutes, the flow of warm air weakens and the waterspout collapses.


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