Bayesian Yacht Sinking: Climate Change Created Perfect Storm for Waterspouts

The waterspout blamed for the deadly sinking of a luxury superyacht carrying the British tech billionaire Mike Lynch in Italy has been called a freak “black swan” event. But scientists believe this kind of marine tornado is becoming more common with global warming.

While the cause of the sinking of the Bayesian hasn’t officially been determined, weather conditions and witness reports from Sicily, where the yacht was anchored off the coast, have led experts to suspect a waterspout, a whirling column of air and water mist. The key factor for waterspout formation is warm water—and the past year has seen the ocean surface heat up to record-breaking temperatures, in part due to climate change.

“If this rate of warming is going to be continuing in the future, it’s very possible these phenomena will be common and not rare,” says Michalis Sioutas, a meteorology PhD who studies waterspouts in Greece and is a board member of the Hellenic Meteorological Society. “It’s very possible to talk about waterspouts or even tornadoes and extreme storms becoming common.”

The 180-foot Bayesian sank in a matter of minutes after a sudden storm with strong winds and intense lightning snapped its mast around 4 am on Monday. Fifteen people who had been aboard were rescued, and one person was found dead. Six people are missing, including British tech billionaire Mike Lynch, who was recently cleared of fraud charges over the sale of his company to Hewlett-Packard. On Wednesday, the bodies of five people were recovered from the sunken ship but have yet to be identified.

Fishermen saw a waterspout near the yacht shortly before it sank, and a nearby schooner was tossed about by what its captain, Karsten Borner, called a “hurricane gust,” which he believes capsized the Bayesian. Experts have said the conditions were ripe for a waterspout.

This extreme weather phenomenon occurs when warm, moist air rises rapidly over water, spinning as winds change direction at different heights. The result is a long, bending funnel of spray between the water and the clouds, tapering off as it rises as much as 10,000 feet into the heavens.

It comes in two flavors. The more vanilla kind is a fair weather waterspout, which forms in relatively calm and even sunny conditions, often under a billowy cumulus cloud. It happens more often in places like the Great Lakes and the Florida Keys, reaches wind speeds of 50 miles per hour, and usually breaks up before it can cause significant damage.

Then there are severe waterspouts, essentially tornadoes over water, which “are another beast” entirely, according to Wade Szilagyi, a retired forecaster at the Meteorological Service of Canada who now directs the International Center for Waterspout Research. These tornadic waterspouts can move from land to water, or vice versa, and twist at 125 miles per hour or more. They’ve been known to throw debris, rip apart buildings, and overturn boats.

A waterspout documented by Sioutas in Methoni, Greece, in 2004 picked up a boat and sent it sailing through the air, striking and killing a 10-year-old boy. Last year, a sudden storm and waterspout with winds of over 40 miles per hour overturned a tourist boat carrying off-duty intelligence agents on Italy’s Lake Maggiore, killing four. Sioutas says waterspouts can even generate “massive water displacements similar to tsunamis,” citing the gigantic waves that struck the coast of the Greek island of Samos during a 2004 cyclone, tossing boulders like toys.

Tornadic waterspouts spring up only in stormy weather with strong winds, lightning, and sometimes hail, and are the product of two main ingredients: wind shear and rising, unstable air. The process begins when masses of cold and warm air collide. This brings together winds from different directions that start to spin around each other, creating vortices. If a thunderstorm also converges in the area, it can provide the instability, sucking warm air up into itself at dizzying speeds. Over water, it starts carrying moisture up as well. Szilagyi compares the waterspout’s development to a twirling figure skater.

“You can think of the skater, if she just spins around normally, that’s like the little vortex that’s already started,” he says. “But if she brings her arms in, then that’s like the column of that unstable warm air, pulling, stretching that vortex upward. She starts to spin faster.”

Waterspouts have been known and feared since ancient times. In the 1550s in Malta, a waterspout plowed through the harbor of Valletta, reportedly destroying an armada of warships and killing hundreds of people. It’s even thought that old stories of fish or frogs raining down on land may be the product of waterspouts sweeping the creatures up into the clouds.

Now global warming may be supercharging the phenomenon. The International Panel on Climate Change has not found a definite link—there hasn’t been much research into how climate change may be affecting waterspouts—but experts say that the conditions for waterspouts to form are happening more often. A 2022 study of 234 waterspouts in the Spanish Mediterranean over the past three decades found that they were more likely to break out when the sea surface was warmer, especially above 23 degrees Celsius (73 degrees Fahrenheit). And water temperatures are now at unprecedented levels.

Last year was the warmest on record for the ocean. The heat content of the upper 6,500 feet of the seas was the highest ever seen. The seas broke temperature records every single day between May 2023 and May 2024. Marine heat waves struck areas from Antarctica to the Mediterranean.

“Warmer oceans have more energy and more humidity to transfer to the atmosphere, the most important fuels for storms,” says Luca Mercalli, president of the Italian Meteorological Society. “The contrast of warm sea and colder air that flows over energizes vertical winds that could result in downbursts or waterspouts.” (A downburst is a powerful cascade of wind and rain from a thundercloud.)

That perfect storm of waterspout conditions hit Italy around the time the Bayesian sank. In recent days, a mass of high-level cold air has swept down from the Alps and over the country’s western coast, meeting the exceptionally warm air just above the sea surface. Four days before the Bayesian went down, sea surface temperatures were the hottest ever recorded across the Mediterranean Sea, with a daily median of 28.71 degrees Celsius. The ocean near where the Bayesian was anchored has reached almost 30 degrees Celsius this week, four degrees higher than the 20-year summer average, according to the European Union’s Copernicus Climate Change Service.

Cold and warm air clashed. Winds started spinning, and overheated water provided the ingredient of instability needed for a waterspout outbreak. As a result, a total of 28 waterspouts were documented off the western coast of Italy from August 17 to August 20, according to the International Center for Waterspout Research.

The total number of waterspouts reported has been increasing in recent years, although a major factor has been that more people are able to capture them with phone cameras and post them on social media, Szilagyi says. But he says that warming waters and a longer waterspout season due to climate change are also contributing. In particular, he believes the number of severe waterspouts are on the rise.

“With the increased water temperatures, that’s probably resulting in more frequent tornadic waterspouts,” Szilagyi says. “There’s no scientific evidence yet that they’re getting even stronger. It’s just that they’re becoming more frequent.”

Warming sea waters are also expected to boost other extreme weather events like Mediterranean hurricanes, or “medicanes,” one of which contributed to the flash flood that killed thousands of people in Libya last year.

In this brave new world, countries need to improve early-warning systems and invest more in research to forecast and observe trends in waterspouts, scientists say. “We have to prepared for more dangerous waterspouts possibly in the future,” Sioutas says. “Significantly warmer waters contribute very significantly to the creation of waterspouts, especially the violent ones.”