NOAA National Weather Service
NOAA National Ocean Service
U.S. Coast Guard
Jim Edds - extremestorms.com
NASA/Goddard Space Flight Center Scientific Visualization Studio
They are sometimes seen as threatening funnel clouds descending from stormy skies. Others can be nearly invisible, like a ghostly spiral of wind skimming the sea surface.
These eerie columns of rotating air are known as waterspouts — commonly defined as tornadoes over water.
Waterspouts usually develop over warm tropical ocean waters. They're spotted in the Florida Keys more than any other place in the world. They've also been seen over the waters of the Great Lakes.
Scientists that study waterspouts generally put them in two categories: fair weather and tornadic.
The tornadic waterspouts may often begin as tornadoes over land and then move over water. They also form in severe thunderstorms over a body of water. They can wreak havoc with high winds, hail, and dangerous lightning.
Fair weather waterspouts develop in calmer weather. They form only over open water, developing at the surface and actually climbing skyward towards the clouds.
The size of all waterspouts can range from just a few feet, to several hundred feet wide.
Research shows that fair weather waterspouts exhibit a five-stage life cycle:
Stage 1 is the formation of a disk on the surface of the water, known as a dark spot;
Stage 2 is a spiral pattern on the water surface;
Stage 3 is a formation of a spray ring;
Stage 4 is where the waterspout becomes a visible funnel;
and the lifecycle ends with Stage 5 – where the waterspout decays.
Like many forces in nature, waterspouts can be both beautiful and dangerous. They've been known to overturn boats, damage large ships, and put lives in jeopardy. If you spot one, exercise extreme caution and keep your distance. Don't leave your safety up in the air – try to avoid these turbulent twisters.