Two tropical systems in the Atlantic may soon engage in a rare meteorological phenomenon. Tropical Storm Humberto and a disturbance expected to strengthen into Tropical Storm Imelda are close enough that they could interact through the Fujiwhara Effect.

The Fujiwhara Effect occurs when two storms move within about 800–900 miles of each other and begin rotating around a shared center. Sometimes one absorbs the other; they merge into a bigger system, or they spin off in new directions.

Every case plays out a little bit differently, which makes determining the outcome of two storms in a Fujiwhara Effect scenario a difficult forecast. In this case, the most likely scenario is that Humberto, the stronger storm, could pull Imelda in and absorb it. It is also possible that there is a merger that might create a more powerful storm with an entirely different track. Even less likely is that the two storms could disrupt one another and weaken. 

A Fujiwhara Effect is only possible at this time since Imelda has not actually developed yet. However, there is strong computer model agreement for Imelda to eventually form and interact with Humberto. 

There are some recent examples of the Fujiwhara Effect playing out during hurricane season. In 2020, Tropical Storms Laura and Marco did not fully engage in the Gulf of Mexico because Marco weakened before it was in close enough proximity to Laura. In 2017, Hurricanes Hilary and Irwin performed a textbook Fujiwhara interaction around each other before merging and dissipating without impacting land.

The Storm Station is here for you, on every platform. Your weather updates can be found on News 2, wbrz.com, and the WBRZ WX App on your Apple or Android device. Follow WBRZ Weather on Facebook and X for even more weather updates while you are on the go.