Marine Glossary

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waterspout

A tornado occurring over water. Waterspouts are most common over tropical and subtropical waters, but they can appear at higher latitudes in severe weather. More generally, any funnel cloud regardless of severity that reaches the water surface is referred to as a waterspout. See schematic in G449.

Waterspouts are not uncommon in the waters of the Bahamas, where incidents have been reported of sighting 7 in one hour. They appear descending from the bases of cumulonimbus clouds in squally conditions, especially in the vicinity of squall lines preceding cold fronts. They can appear as distinct centers to squall images on radar. Though prominent ones are consistently less severe than their tornado counterparts on land, they can be clearly cases of strong local winds and definitely to be avoided when possible. Some waterspouts are less intense and are more akin to dust devils on land.

Very close sightings have reported them as producing a loud roaring sound when close at hand, with the water spinning and rising to meet the descending funnel cloud in some cases. They are typically short lived, with the funnel connected to the surface for a few to 10 minutes or so.

Waterspouts have also been sighted in Puget Sound, WA in the presence of strong squalls, although these are rare appearances in these waters.