A waterspout is a tornado that occurs over water — a rotating column of air extending from a cloud base to the water surface, often made visible by spray and condensation. Two distinct types exist: tornadic waterspouts (true tornadoes that move from land to water or form over water in association with supercells — these are violent and dangerous) and fair-weather waterspouts (weaker vortices that form under growing cumulus clouds without severe thunderstorms).
Fair-weather waterspouts are far more common. They form over warm water surfaces when the air is humid and unstable in the lowest layers. The process begins with a dark spot on the water (convergence zone), followed by a spiral pattern of light and dark bands, then a condensation funnel descending from the cloud base while spray rises from the surface. They typically have wind speeds of 60–100 km/h (EF0), last 10–20 minutes, and dissipate upon reaching shore.
The Mediterranean is one of the world's most active waterspout regions, particularly in autumn when sea surface temperatures peak (25–28 °C) while the first cold-air intrusions at mid-levels create instability. Hotspots include the Balearic Islands, the Adriatic Sea, the waters around Malta, and the coasts of Catalonia, Valencia, and the Italian Riviera. Multiple waterspouts can occur simultaneously in waterspout outbreaks. While fair-weather waterspouts are usually weak, they can still capsize small boats, damage marina infrastructure, and cause injuries — mariners should maintain a safe distance and alter course when one is sighted.