Definition
A rotating column of air, similar in structure to a tornado, that forms over a body of water and extends from the base of a cumuliform cloud down to the water surface. Waterspouts can occur as tornadic waterspouts (associated with severe thunderstorms) or fair-weather waterspouts (which form under lighter conditions over warm water), and both produce strong rotating winds capable of damaging aircraft and small vessels.
Plain English
A spinning, funnel-shaped column of air that reaches from a cloud down to the water. It is essentially a tornado over water and contains strong rotating winds.
Context Anchor
Seen in weather and thunderstorm discussions, especially when flying near coastlines, lakes, bays, or warm ocean water.
Derivation
From 'water' plus 'spout,' meaning a stream or jet of water shooting upward. The name comes from the early belief that the funnel was sucking water up from the surface. In reality, the visible funnel is mostly condensed water vapor, with only sea spray near the base — but the name stuck.
Why Pilots Care
Waterspouts create sudden strong winds and turbulence that can damage aircraft or cause loss of control at low altitudes over water.
Analogy
Like a giant twisting hose sucking water and air upward from the sea surface into the clouds.
Grounding Statement
Picture a narrow, spinning column hanging from a cloud over the water, with spray swirling at the surface below it.
Intuition Check
Do not assume a waterspout is just water spraying upward. In aviation weather, treat it as a rotating storm hazard over water.
Example Sentence 1
While flying along the Florida coast, the pilot spotted a waterspout forming under a line of building cumulus clouds and altered course to stay well clear.
Example Sentence 2
Preflight planning included checking for waterspout activity before departing on the over-water leg of the route.