According to Dr. Joseph Golden, a distinguished waterspout authority with the National Oceanic and Atmospheric Administration (NOAA), a waterspout is a funnel which contains an intense vortex, sometimes destructive, of small horizontal extent and which occurs over a body of water.
The belief that a waterspout is nothing more than a tornado over water is only partially true. The fact is, depending on how they form, waterspouts come in two types: tornadic and fair weather.
- Tornadic waterspouts are simply tornadoes that form over water, or move from land to water. They have the same characteristics as a land tornado. They are associated with severe thunderstorms, and are often accompanied by high winds and seas, large hail, and frequent dangerous lightning.
- This type of event happened in Brunswick County when a landfalling EF-0 tornado grew into an EF-3 tornado a little after 11:30pm on February 15, 2021. The storm killed three people and injured 10 others. We can also see this type of waterspout phenomenon with landfalling tropical weather systems, particularly in the right-front quadrant of the storm at is comes on shore.
- In 2011, a waterspout came onshore in Carolina Beach and caused minor damage.
- Fair Weather waterspouts are usually a less dangerous phenomena, but common over the coastal waters along New Hanover County from late Spring through early Fall, and generally much more common than the tornadic variety. The term fair weather comes from the fact that this type of waterspout forms during fair and relatively calm weather, often during the early to mid morning and sometimes during the late afternoon. Fair weather waterspouts usually form along dark flat bases of a line of developing cumulus clouds where cooler air moves over warmer ocean water. This type of waterspout is generally associated with the formative stage of showers and non-severe thunderstorms whereas tornadic waterspouts develop in mature severe thunderstorms.
- Here is a video from WECT from July 24, 2022 when a fair weather waterspout was caught on video.
Tornadic waterspouts develop downward in a thunderstorm while a fair weather waterspout begins to develop on the surface of the water and works its way upward. By the time the funnel is visible, a fair weather waterspout is near maturity.
- If a waterspout is sighted, immediately head at a 90 degree angle from the apparent motion of the waterspout.
- If a waterspout moves onshore, the National Weather Service issues a tornado warning as even these waterspouts have the potential to produce localized damage and injuries to people. Follow the same steps you would for any tornado warning.
- Typically, fair weather waterspouts dissipate rapidly when they make landfall, and rarely penetrate far inland.
- Never try to navigate through a waterspout. Although waterspouts are usually weaker than tornadoes, they can still produce significant damage to you and your boat.
- Never move closer to investigate a waterspout.
- Pay attention to EAS, NOAA Weather Radio, and local authorities for updated information.
- If the waterspout came ashore, stay clear of fallen power lines or broken utility lines.