Florida Keys Waterspout Basics
Tropical Funnel-shaped Vortex Creating Fish Falls and Raining Frogs
Defined as a tornado happening over water, waterspouts cause destruction with strong winds, swirling sea spray into a funnel-shaped vortex lifting debris into the air.
What is a Waterspout?
A waterspout is a tornado happening over water, or a tornado moving from land to water. The American Meteorological Society defines a waterspout as “any tornado over a body of water, or a non-supercell over water.” Supercell refers to a large group of clouds forming a supercell thunderstorm. Tornadoes and waterspouts happen on rare occasion but can both be destructive and deadly. Though weaker and smaller than tornadoes on land, waterspouts can be destructive with flying debris and damage. Waterspouts usually last 5-10 minutes but can continue for as long as one hour.
Where Do Waterspouts Occur?
Waterspouts can happen wherever there is water. However, for the most part, waterspouts take place in tropical water, especially during warm temperatures of the wet season. In 1969, the Lower Florida Keys Waterspout Project, led by Dr. Joseph H. Golden, observed 390 waterspouts in a 4-month period, within a 50-mile area. Dr. Golden concluded that waterspouts happen in the Florida Keys more than any other place in the world. Waterspouts have been known to occur over the Great Lakes, Lake Tahoe, the Atlantic Ocean, the Indian Ocean and the Bay of Bombay.
Waterspout Structure
Waterspouts share a similar funnel-shaped structure with tornadoes, with a large updraft of air occurring within a group of clouds, usually a thunderstorm. The National Weather Service, or NWS, has identified two categories of waterspouts.
- Fair weather waterspouts – These waterspouts develop from cumulus clouds. They work upward from the water’s surface, forming under light wind. Fair weather waterspouts are usually rare and short lived.
- Tornadic waterspouts – These waterspouts are the typical tornadoes formed over water, or tornados that move to water from land. Tornadic waterspouts are associated with thunderstorms. The waterspouts form by moving down from the thunderstorm, towards the water below.
The National Oceanic and Atmospheric Administration has identified waterspouts as having a 5-stage life cycle.
- Dark-spot stage – appears on water surface but not always visible
- Spiral pattern stage – patterns of dark and light-colored bands spirals out from dark spot
- Spray-ring stage – swirling “sea spray” from the dark-spot, eventually moving upwards with increased wind speed
- Mature or spray vortex stage – a visible waterspout from water surface to cloud base with maximum strength
- Decay stage – the waterspout vortex weakens and rain falls, containing sea water and rain
Fish Falls From Above
One unusual meteorological phenomenon associated with waterspouts is “fish falls” or raining frogs. When these waterspouts whirl over water, the strong winds can pick up debris, even live animals!
Waterspouts can suck up fish, frogs and other animals. The animals are lifted up through the updraft of the funnel. The animals can be carried miles away.
Eventually as the decay stage comes, the animals fall to the ground below, sometimes unharmed, but frightened. Fish, frogs, birds, jellyfish, worms and lizards have all been known to fall from the sky, after being sucked up by a waterspout or tornado.
Waterspout Danger
Waterspouts can be very dangerous for mariners and boaters. The NWS warns people to avoid waterspouts and not move closer to observe. Move away from waterspouts by moving at a 90-degree angle to its movement. People should take precautions as waterspouts can be just as dangerous as tornadoes.
