Hurricane Humberto rapidly strengthening and may soon be joined by Imelda, posing a US threat
Two tropical systems will churn near each other in the Atlantic, with Humberto forecast to strengthen and a second storm possibly forming as Imelda, raising risks of flooding and damaging winds in the United States.
AccuWeather’s Bernie Rayno and Jon Porter monitor the Atlantic, where there are two storms. A tropical storm threat could bring potentially life-threatening flooding to the Carolinas early next week.
A rare weather pattern is unfolding in the southwestern Atlantic with the possibility of two hurricanes swirling within a few hundred miles of one another. One could make landfall along the United States' coast early next week, potentially posing a significant risk from flooding rain, damaging wind gusts and coastal inundation.
"The proximity of two storms expected within hundreds of miles of each other has made this a challenging and complex forecast," AccuWeather Lead Hurricane Expert Alex DaSilva said.
AccuWeather hurricane experts are becoming increasingly concerned about the possibility of a landfalling storm along the southeastern U.S. coast next week.
In this image, captured on Friday afternoon, Sept. 26, 2025, Hurricane Humberto can be seen right of center. The tropical rainstorm could be seen over Hispaniola, eastern Cuba and the Turks and Caicos Islands. The rainstorm is forecast by AccuWeather to become a tropical storm in the coming days. (AccuWeather Enhanced RealVue™ Satellite)
The setup is rare and highly complex. The last time something similar occurred near the U.S. was in 2016, when Hurricanes Matthew and Nicole were about 800 miles apart. Early next week, two hurricanes could be about half that distance apart, with the potential for interaction between them affecting the track and strength of each storm.
Humberto strengthened into the Atlantic basin's third hurricane of the season Friday morning. The storm is forecast to reach major hurricane status this weekend and may track just west of Bermuda. Meanwhile, a batch of showers and thunderstorms near Hispaniola is forecast to evolve into a tropical storm near the Bahamas in the coming days. If the new system becomes a named storm, it would be called Imelda, the next name on the 2025 Atlantic hurricane list. From there, quick strengthening is possible with at least one scenario for the storm to make landfall in the Carolinas as a potent hurricane with torrential rain and strong winds.
Humberto to impact Bermuda
Humberto will continue to intensify over the coming days.
"Humberto may rapidly intensify as it slowly turns to the northwest this weekend. This hurricane is forecast to pass between Bermuda and the U.S. East Coast next week. Humberto may bring gusty winds and several inches of rain to Bermuda," DaSilva said.
How significant wind, rain, flooding and waves are in Bermuda will depend on the strength and proximity of the hurricane to the islands. A close encounter with a major hurricane passing just to the west is often much more dangerous than a similar hurricane passing to the east, such as what occurred with Gabrielle.
Tropical rainstorm forecast to evolve into Imelda
The second tropical concern is a group of showers and thunderstorms near eastern Cuba. Because of the high risk of full tropical development with this feature, AccuWeather is referencing it as a tropical rainstorm to raise public awareness.
"The tropical rainstorm moving toward the Bahamas will enter an area with less disruptive wind shear and very warm waters. Atmospheric conditions near the Bahamas should support tropical development over the weekend," DaSilva said.
Heavy rainfall, gusty winds and rough seas can occur across Hispaniola, Cuba and the Bahamas as the storm begins to organize.
Depending on how quickly the tropical rainstorm evolves into an named tropical storm and potentially a hurricane will determine the severity of wind, flooding and wave conditions in the Bahamas.
Beyond the Bahamas, interaction with Humberto may be significant and could pull the storm away from the U.S. or steal some of its moisture. In this scenario, rain impacts from the budding Imelda could be limited in the southeastern U.S.
On the other hand, if both storms remain separate enough with minimal interaction, the budding Imelda could push directly onshore into the Carolinas early next week, perhaps as a hurricane with damaging winds, coastal flooding, erosive waves and flooding rainfall.
To further complicate the situation, a non-tropical storm will bring showers and thunderstorms to part of the Southeast into this weekend and may bring localized flooding regardless.
The risk of significant flash flooding could extend as far west as the southern Appalachians. Recall that about a year ago, Hurricane Helene unleashed tremendous rain in the southern Appalachians, which led to disastrous and deadly flooding. The hardest-hit communities are still struggling a year later.
In a worst-case scenario, heavy rain from both tropical and non-tropical origins could bring prolonged, tremendous rain and flooding to parts of the Carolinas and Georgia, with the potential for damage comparable to impacts from Hurricane Matthew in 2016.
Period of rough seas, dangerous surf and beach erosion
Regardless of whether a hurricane makes landfall in the southeastern U.S. or not, strong winds will create large, chaotic swells that will propagate toward the southern and middle Atlantic coast late this weekend to the middle of next week.
Assisting will be an area of high pressure over the Northeast, causing winds to blow from the ocean toward the land.
Coastal flooding is possible along barrier islands and back bays, so interests in these areas should monitor updates. Large, frequent breakers will create strong rip currents and lead to beach erosion. Seas near the coast and offshore will be hazardous for small craft and large vessels.
Rare atmospheric interaction possible: the Fujiwhara Effect
An atmospheric phenomenon known as the Fujiwhara Effect could occur next week with both tropical systems spinning around each other. This rare tropical interaction is named after Japanese meteorologist Sakuhei Fujiwhara, who first described the condition in a 1921 research paper.
The condition is similar to the teacup ride at an amusement park or ballroom dancers moving in unison.
In this highly complex scenario, the storms may stall offshore, rotate around one another or one could be steered toward the U.S. coast.
Residents, business owners and visitors in Bermuda, the northern Caribbean, the Bahamas and the eastern U.S. should monitor the progress of both Humberto and the tropical rainstorm.
Changes in track and intensity could significantly affect rain and wind impacts.
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