Tropical Storm Humberto forms, to become major hurricane off southeast US coast
A new tropical storm (Humberto) has developed over the Atlantic Ocean, and AccuWeather meteorologists warn another one (Imelda) could soon join it just off the coast of the southeastern United States.
AccuWeather’s Alex DaSilva was live on the AccuWeather Network on Sept. 25 to discuss the latest on multiple storms in the Atlantic.
A new tropical storm has taken shape over the Atlantic Ocean and is predicted to become the next hurricane of the season. It could be quickly followed by yet another storm that may threaten the southeastern United States.
Tropical Storm Humberto formed on Wednesday afternoon, one day after AccuWeather called the area of strengthening showers and thunderstorms a tropical rainstorm to raise awareness of the growing tropical threat. Meanwhile, a tropical wave crossing the northern Caribbean is also showing signs of development, raising concerns for the Bahamas and potentially the U.S. East Coast.
The latest on Tropical Storm Humberto
As of Thursday morning, Tropical Storm Humberto was located about 480 miles east-northeast of the northern Leeward Islands. It had maximum sustained winds of 45 mph and was traveling northwest at 10 mph.
A satellite image of Tropical Storm Humberto shortly after it developed on Sept. 24, 2025. (AccuWeather Enhanced RealVue™ Satellite)
Humberto is forecast to take a curved path between Bermuda and the East Coast of the U.S.
"We expect it to intensify into a hurricane this weekend," AccuWeather Lead Hurricane Expert Alex DaSilva said.
The dashed red line is the AccuWeather forecast path for Humberto's eye. The shaded areas are alternative paths the center of the storm could take based on changing steering conditions. Impacts will extend well beyond the eye.
Humberto is forecast to overcome dry air and combative winds, and become the next major hurricane of the season between Bermuda and the U.S. It could peak as a Category 4 hurricane.
This storm may track close enough to Bermuda to bring rain and gusty winds starting Sunday night or early Monday.
One certainty is that seas, surf and increasing rip currents will build and impact beaches across the Bahamas, Bermuda and the East Coast starting this weekend and perhaps lasting through the middle of next week. There are strong indications that Humberto will have a great deal of help doing so.
The next tropical threat
Assisting with the likelihood of rising seas and surf is a tropical wave currently tracking westward over the northern islands of the Caribbean.
"While this current tropical wave was poorly organized at midweek, it has a high chance of tropical development late this week and especially the weekend as it pulls away from the mountainous land mass of Hispaniola and nears the small islands and shoals of the Bahamas," DaSilva said.
"Regardless of tropical development, this wave will bring downpours and gusty winds to parts of the Puerto Rico, the Dominican Republic and Haiti," DaSilva added. Downpours kicked up over the British and U.S. Virgin Islands on Wednesday night.
There is the potential for dangerous flash flooding, mudslides and sporadic power outages in some locations as this tropical wave moves along over the northern Caribbean islands.
Depending on the track and organization of the tropical wave, more significant wind and rain may develop as it moves across the Turks and Caicos and the Bahamas.
It may be of the most concern to areas along the southern Atlantic coast of the U.S. during the first part of next week.
While there is some potential that Humberto to the east may hinder the full development of the tropical wave farther west, both could evolve into hurricanes. Since the tropical wave farther west may be close to or could reach the U.S. coast, it could bring significant impacts in terms of wind, rain and surf.
Moisture over the western Atlantic, not associated with the tropics, will bring localized downpours and thunderstorms to parts of the Southeastern states this weekend to early next week. Some of that rain could be heavy enough without tropical intervention to trigger flash flooding. Should the Caribbean tropical entity reach the U.S. coast, the combined moisture could bring excessive rainfall and widespread flooding.
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Something really crazy could happen
An atmospheric phenomenon known as the Fujiwhara Effect could occur next week with both tropical systems spinning around each other. This very rare storm behavior 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, direct rain from both could remain offshore, or one or both could be flung toward the U.S. coast.
There is also the potential that Humberto, which has a head start, becomes so strong that it absorbs the Caribbean entity or much of its moisture. In that case, little rain and wind may affect the southern Atlantic Coast of the U.S.
Interests in Bermuda, the northern Caribbean, the Bahamas and the eastern U.S. should monitor the progress of both Humberto and the organizing tropical waves, as changes in track and intensity could significantly affect rain and wind impacts.
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