Waterspouts are a relatively common sight over the waters surrounding the U.S. Virgin Islands, and the weather phenomenon can be both beautiful and dangerous for boaters and swimmers. Understanding how they form, their types, and when they’re most likely to occur can help keep people informed and safe.
Interestingly, waterspouts come in two forms: “fair weather waterspouts” and “tornadic waterspouts.” The National Oceanic and Atmospheric Administration notes that fair-weather waterspouts are more common than tornadic waterspouts.
“A waterspout is a whirling column of air and water mist,” according to information from NOAA. “Tornadic waterspouts are tornadoes that form over water or move from land to water. They have the same characteristics as a land tornado and are associated with severe thunderstorms, and are often accompanied by high winds and seas, large hail, and frequent dangerous lightning,” the NWS explained.
“Fair weather waterspouts usually form along the dark flat base of a line of developing cumulus clouds,” the NWS stated. “This type of waterspout is generally not associated with thunderstorms. While tornadic waterspouts develop downward in a thunderstorm, a fair weather waterspout develops 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. Fair weather waterspouts form in light wind conditions, so they normally move very little,” NOAA said.
Waterspouts, Further Explained
The Source spoke with Alex DaSilva, AccuWeather’s lead hurricane expert, to learn more about waterspouts and the different types that occur in the region. DaSilva provided insight into the possible damage that waterspouts can cause and tips on what to do if residents and visitors encounter a waterspout.
“Waterspouts most commonly occur in the tropics, although they can occur anywhere over water, even on large lakes,” DaSilva said. “They are most common in the warm season.”
“Fair-weather waterspouts typically form along a boundary and usually don’t have strong thunderstorms associated with them. These typically remain over the water and are usually not a threat to people on land,” DaSilva added.
“Tornadic waterspouts are basically tornadoes over water,” DaSilva stated. “They are usually more powerful and can cause damage if they move inland, and if they move on land, they are called tornadoes. This can happen, leading to a lot of damage in some cases. Tornadic waterspouts form the same way as tornadoes, and these waterspouts can be common in tropical storms and hurricanes.”
DaSilva explained how common it is for a waterspout to form during a cyclone.
“Tornadoes/waterspouts associated with tropical storms and hurricanes are usually less powerful overall than you would see in ‘tornado alley’ in the United States,” DaSilva said. “However, they still can be very powerful, and there were multiple EF-2 and EF-3 scale tornadoes during the last hurricane season in Florida,” he continued.
“Some storms produce a lot of tornadoes, and some produce little to none,” DaSilva acknowledged. “This is still an active area of research, but there are signs that when a hurricane interacts with a dip in the jet stream, it can allow for more tornadoes and waterspouts due to more spin in the atmosphere. We saw that in Hurricane Milton in 2024,” he said.
“Tornadoes typically form on the right side of the hurricane’s motion,” DaSilva specified. “For example, if a hurricane is moving west, the waterspouts are most likely to occur on the northern side. If a storm is moving north, then they will be on the eastern side. The reason the tornadoes are more likely on the right side of the storms motion is because there tends to be more cyclonic spin in that part of the storm,” DaSilva explained.
Recognize a Waterspout
During a waterspout, the spinning columns of water can pose a threat to individuals who are swimming, boating, or spending time along the coastline.
“Both types of waterspouts can be dangerous to boaters,” DaSilva declared. “Meteorologists encourage all boaters and beachgoers to have a way to receive severe weather warnings,” he advised.
“While most waterspouts will remain over water with no threat to land, some do have the potential to move on land, and you would want to immediately take shelter, the same as you would in a tornado if one starts to approach,” DaSilva advised.
Indeed, it is crucial to remain vigilant and recognize the patterns often associated with a waterspout’s life cycle.
Information from National Geographic provided the following information about the five stages of development and progression of a waterspout:
- Dark spot. The surface of the water takes on a dark appearance where the vortex, or column of rotating wind, reaches it.
- Spiral pattern. Light and dark bands spiral out from the dark spot.
- Spray ring. A swirling ring of sea spray called a cascade forms around the dark spot. It appears to have an eye at the center, similar to that seen in a hurricane.
- Mature vortex. The waterspout is now at its most intense stage, visible from the surface of the water to the clouds overhead. It appears to have a hollow funnel and may be surrounded by vapor.
- Decay. When the flow of warm air into the vortex weakens, the waterspout collapses.
“The average spout is around 50 meters (165 feet) in diameter, with wind speeds of 80 kilometers per hour (50 miles per hour), corresponding to the weakest types of tornadoes on land. The largest waterspouts can have diameters of 100 meters (330 feet) and last for up to one hour, though the average lifetime is just five to 10 minutes,” according to National Geographic.
If a waterspout is suspected via radar imaging, the NWS will issue alerts to the public to warn individuals.
“When waterspouts have been detected by Doppler Radar or reported by local law enforcement or spotters, the NWS issues a Special Marine Warning,” the NWS said. “Since it is not uncommon for numerous waterspouts to occur simultaneously over a large area, these warnings tend to cover larger geographic areas than land-based tornado warnings, which generally cover a single county,” the NWS continued.
“If a waterspout moves onshore, the NWS issues a tornado warning, as some of them can cause significant damages and injuries to people. Typically, fair weather waterspouts dissipate rapidly when they make landfall and rarely penetrate far inland,” the NWS added.
Take Action if in the Path of a Waterspout
If a waterspout develops, individuals along the coastline should exit the water if swimming and take shelter away from the shore in case the vortex moves inland. Boaters are advised to remain at a safe distance from a funnel and travel at a 90-degree angle away from where the waterspout is moving.
The NWS offers the following tips in order to stay safe from a waterspout:
- Listen for special marine warnings about waterspout sightings that are broadcast on NOAA Weather Radio.
- Watch the sky for certain types of clouds. Look for a possible waterspout underneath a line of cumulus clouds with dark, flat bases. Any time of the year, a thunderstorm or line of thunderstorms can produce very intense waterspouts.
- If a waterspout is sighted, immediately head at a 90-degree angle from the apparent motion of the waterspout.
- 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.
Hurricane Season and Weather Forecast Information
In addition to the year-round threat of waterspouts, USVI visitors are encouraged to prepare now for the potentially active 2025 Atlantic Hurricane Season, which begins on June 1 and lasts until Nov. 30.
In addition to obtaining weather information from the NHC, the NWS, and NOAA, the local weather forecast for the U.S. Virgin Islands is regularly updated on the Source Weather Page and VI Source YouTube Channel. Individuals can also find helpful weather information and alerts from the Virgin Islands Territorial Emergency Management Agency.
A video of a distant waterspout off the northside of St. Croix on May 16 can be viewed here.
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