Tropical Storm Imelda forecast to strengthen into a hurricane, Humberto maintains Category 4 strength
Tropical Storm Imelda formed over the Atlantic on September 28, 2025, as Hurricane Humberto peaked at Category 5, and dropped back to Category 4. While neither of the storms is expected to make landfall over the contiguous United States, they could produce hazardous conditions for the southeastern states including Florida, South Carolina, and much of the East Coast this week.
Satellite image of Tropical Storm Imelda and Hurricane Humberto at 08:20 UTC on September 29, 2025. Credit: NOAA/GOES-East, RAMMB/CIRA, The Watchers
Tropical Depression 9 strengthened into Tropical Storm Imelda on September 28, becoming the 9th named storm of the 2025 Atlantic hurricane season.
At 02:00 EDT (06:00 UTC) on September 29, Imelda was located roughly 209 km (130 miles) northwest of central Bahamas, and 507 km (315 miles) southeast of Cape Canaveral, Florida. Sustained winds (averaged over 1 minute) reached 72 km/h (45 mph), with higher gusts. The system was moving northward at 13 km/h (8 mph), with a minimum central pressure of 996 hPa.
A Tropical Storm Warning has been issued for the central Bahamas (including Cat Island, the Exumas, Long Island, Rum Cay, and San Salvador) and parts of the northwestern Bahamas (including Eleuthera, New Providence, the Abacos, Berry Islands, Andros Island, and Grand Bahama Island).
The warning means that tropical storm conditions, like strong winds and heavy rain, are expected in these areas within the next 12 hours.
While earlier forecast indicated that the storm could make landfall over the southeastern U.S. the latest track forecast shows Imelda will pass close to the coast, without moving onshore. It will, however, pass close to the eastern coast of Florida, bringing tropical storm conditions to the region on September 29.
Imelda is expected to continue moving generally northward, and cross the northwestern Bahamas on September 29. It is then forecast to take a sharp east-northeast turn, as it strengthens into a hurricane on September 30.
Some uncertainty exists regarding Imelda forecast track, due to various variables in atmospheric conditions. These include proximity to major Hurricane Humberto – multiple forecast models suggest Imelda could still track close enough to the Southeast coast to bring significant impacts from Florida to North Carolina.
The National Hurricane Center (NHC) said storm rainfall totals of 51 to 102 mm (2–4 inches), with locally higher amounts of up to 180 mm (7 inches), are expected through Wednesday morning across portions of the coastal Carolinas. That rainfall could result in flash, urban and isolated, minor river flooding.
However, the NHC said changes to the forecast track would also change the forecast rainfall totals.
Minor coastal flooding is also possible in areas with onshore winds over the southeastern U.S. Areas from the Volusia/Brevard County line in Florida to the South Santee River in South Carolina could see a 30 to 60 cm (1–2 feet) storm surge.
A preemptive state of emergency was declared by South Carolina by Governor Henry McMaster on September 26 activating statewide response plans and mobilizing agencies to prepare for significant wind, flooding rain and storm surge across the state.
“As this storm approaches our coast, I am issuing a State of Emergency to ensure Team South Carolina is able to access and deploy the resources and personnel needed to prepare for and respond to this storm,” said Governor Henry McMaster.
“While the storm’s arrival, speed, and intensity remain hard to predict, we do know that it will bring significant wind, heavy rainfall, and flooding across the entire state of South Carolina. We have seen this before. Now is the time to start paying attention to forecasts, updates, and alerts from official sources and begin making preparations,” added McMaster
The City of Charleston declared a local state of emergency September 27, and began distributing sandbags and clearing storm drains, according to a statement.
Meanwhile, over the open Atlantic, Hurricane Humberto rapidly intensified into a rare Category 5 hurricane on September 27 while tracking over warm water and a less hostile environment in the central Atlantic. It then weakened to category 4 strength by September 28.
As of 02:00 AST (06:00 UTC) on September 29, Humberto was located around 644 km (400 miles) south-southwest of Bermuda, maintaining its Category 4 classification. Maximum sustained winds (averaged over 1 minute) reached 225 km/h (140 mph) with higher gusts. It was moving northwest at 23 km (14 mph), with an estimated minimum central pressure of 928 hPa.
Humberto will produce dangerous surf condition for Bermuda and most of the U.S. east coast through the week. These conditions are subject to change, as it is still too early to predict the effects of Imelda’s interactions with Humberto.
A Tropical Storm Watch has been issued by the NHC for Bermuda on September 29. Swells generated by Humberto will continue to affect portions of the northern Leeward Islands, the Virgin Islands, Puerto Rico, and Bermuda through much of this week.
“Swells from Humberto will also impact the U.S. East Coast beginning on September 29. These swells are likely to cause life-threatening surf and rip current conditions” said the NHC.
Tropical storm conditions are possible on Bermuda starting early morning on September 29. Humberto is also forecast to drop 25–50 mm (1–2 inches) of rainfall over Bermuda from the night of September 29 into September 30.
References:
1 Tropical Storm Imelda Intermediate Advisory Number 10A – NHC – September 29, 2025
2 Hurricane Humberto Intermediate Advisory Number 18A – NHC – September 29, 2025
I am an Assistant Editor and Severe Weather & Science Journalist at The Watchers, specializing in real-time severe weather coverage, geophysical event reporting, and research-driven scientific analysis. You can reach me at rishav(at)watchers(.)news.
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