Two tropical cyclones are racing through the Atlantic, possibly on a collision course. If they collide, they could create a significant storm that might cause problems along the East Coast.
Tropical Storm Hunbert formed in the North Atlantic on Wednesday and is expected to strengthen into a major hurricane this weekend. Meanwhile, another system moving into the Caribbean could gain strength from Tropical Storm Imelda in the days ahead.
If these two storms get too close, they might trigger a rare weather phenomenon called the Fujisawa effect.
What is the Fujisawa Effect?
This effect, named after Japanese meteorologist Sato Fujiwara in 1921, occurs when two cyclones are within 900 miles of each other, causing them to rotate around a common center—a sort of chaotic dance.
“The Fujisawa Effect happens when the storms approach and start interacting,” a meteorologist noted. “Essentially, they dance around each other. For tropical systems, they have to be within 900 miles; for non-tropical storms, it’s about 1,200 miles.”
What unfolds next can vary—sometimes they combine into a single massive storm, according to the National Weather Service.
However, as seen in 2017 with Hurricanes Hillary and Irwin, if they match evenly, they might spin around each other without truly merging.
On the flip side, stronger storms can absorb weaker ones, as was the case with Typhoon Hinnamnor interacting with a tropical depression in 2022.
Each interaction presents a major forecasting challenge for meteorologists.
Although this is relatively rare in the Atlantic, it’s more common in the Western Pacific, which produces tropical systems more frequently, often far from land.
Tropical Storm Hunbert Prediction
Hunbert is currently moving through the Sargasso Sea with sustained winds of 50 mph and is expected to become a hurricane by Friday night, potentially reaching Category 3 status by early next week.
While it’s not an immediate threat to the U.S., residents of Bermuda are advised to monitor the situation closely.
“I believe Hunbert will stay at sea, away from the U.S., posing no direct threat,” the meteorologist said. “Carolina might get some extra rain due to moisture from the storm, but Bermuda should keep a close eye on forecasts as changes may occur next week.”
As for Imelda, now referred to as Invest 94L, it’s already bringing rain to Puerto Rico, the Virgin Islands, and Hispaniola, according to forecasters.
Invest 94L could intensify over the next few days, posing dangers to the coasts of Georgia and the Carolinas, with potential for damaging winds and severe flooding starting Sunday.
Storms could also be influenced by terrain in the Dominican Republic, spurring them to stall before moving toward Bermuda.
As for the likelihood of the two storms interacting, that seems “unlikely,” according to the meteorologist.
“Right now, the prevailing scenario suggests that a larger low-pressure system will pull Imelda north, keeping it separate from Hunbert,” he explained.
