A rotating column of air over a body of water, functionally similar to a tornado but usually weaker and shorter-lived. Fair-weather waterspouts form from developing cumulus clouds over warm water without a parent thunderstorm, while the rarer tornadic waterspout is a true tornado that has moved over water or formed from a severe storm above it. They are common over warm, tropical and subtropical waters such as the Florida Keys.
Facts
PeriodicityMost common in late summer, with September the prime month of formation in the Northern Hemisphere; in Europe roughly 160 are reported per year, most from the Netherlands, Spain and Italy. 1 ScaleThe common fair-weather type is a weak, short-lived vortex, usually rating no higher than EF0 on the Enhanced Fujita scale with winds under about 30 m/s (108 km/h), and lasting less than 20 minutes. 1 First DescribedSeveral waterspouts off the east coast of Australia were described by the naturalist Joseph Banks during the voyage of the Endeavour in 1770. 1 Identification
Distinguishing AppearanceA rotating column of air over water, usually a funnel-shaped cloud in contact with the water surface and a cumuliform cloud above; the fair-weather type develops through five stages: a dark spot on the water, a spiral pattern, a spray ring, a visible condensation funnel, and decay. 1 Connections
Demonstrated By
Marine, Biomes Source National Oceanic and Atmospheric Administration
Sources
1. Waterspout (Wikipedia)
WikipediaWikipedia 'Waterspout', lead section
A fair weather waterspout has a five-part life cycle: formation of a dark spot on the water surface; spiral pattern on the water surface; formation of a spray ring; development of a visible condensation funnel; and ultimately, decay.
Wikipedia 'Waterspout', Climatology section
They usually rate no higher than EF0 on the Enhanced Fujita scale, generally exhibiting winds of less than 30 m/s (67 mph; 108 km/h).
Wikipedia 'Waterspout', lead section (periodicity sentence)
They are most common in late summer. In the Northern Hemisphere, September has been pinpointed as the prime month of formation.
Wikipedia 'Waterspout', lead section (first-described sentence)
Waterspouts are also frequently observed off the east coast of Australia, with several being described by Joseph Banks during the voyage of the Endeavour in 1770.
Wikipedia 'Waterspout', lead section (distinguishing-appearance sentence)
A fair weather waterspout has a five-part life cycle: formation of a dark spot on the water surface; spiral pattern on the water surface; formation of a spray ring; development of a visible condensation funnel; and ultimately, decay.
View the Source National Oceanic and Atmospheric Administration
National Oceanic and Atmospheric AdministrationDemonstrated By: MarineView the Source Reader Challenges (0)
No disputes yet. Spotted an error or a better source? Open the first one.
Sign in to dispute this or suggest a correction.