A new tropical storm, Josephine, formed off Africa behind Tropical Storm Ike. Both were moving westward just as Hurricane Gustav dissipated after slamming into the U.S. Gulf Coast near New Orleans.

The flurry of Atlantic storms underscored predictions for a busier than normal hurricane season and was worrisome news for US oil and natural gas producers in the Gulf of Mexico, millions of people living in the Caribbean and on U.S. coasts, and farmers fearing flooded fields.

The US government has forecast 14 to 18 tropical storms will form during the six-month season that began on June 1, more than the historical average of 10. Josephine was already the 10th, forming before the statistical peak of the season on Sept. 10.

By Tuesday night, Hanna was bearing down on Great Inagua Island with 65 mph (100 kph) winds, the U.S. National Hurricane Center said.

It was expected to strengthen back into a Category 1 hurricane on the five-step Saffir-Simpson scale of intensity, with winds of at least 74 mph (119 kph) on Wednesday or Thursday.

Hanna dumped torrential rains on the southeastern Bahamas, the Turks and Caicos islands, Haiti and the Dominican Republic.

In Haiti, heavy rains caused severe flooding in the northern port city of Gonaives, where thousands of people died four years ago during a similar catastrophe.

"The city is flooded and there are parts where the water gets to 2 meters (6.5 feet)," said civil protection director Alta Jean-Baptiste. "A lot of people have been climbing onto the tops of their houses since last night to escape the flooding."

Authorities said flooding and mudslides from the storm killed at least 25 people across Haiti, including 12 in low-lying Gonaives and three in the nearby town of Gros Morne.

FLORIDA EMERGENCY

Hanna was nearly stationary but was forecast to turn northwest on a track that would take it near the Bahamian capital of Nassau and near the US East Coast on Thursday. It was likely to come ashore at the end of the week somewhere between northern Florida and the Carolinas.

Although the official forecast kept it over water as it skirted the Florida coast, state Gov Charlie Crist declared a state of emergency.

Tropical Storm Ike headed west after forming on Monday between Africa and the Caribbean and appeared likely to become a hurricane that would threaten the Caribbean islands and possibly the United States.

It was too early to say where Ike might go but the storm drew the attention of energy companies running the 4,000 offshore platforms in the Gulf of Mexico that provide the United States with a quarter of its crude oil and 15 percent of its natural gas.

Ike was about 930 miles (1,500 km) east-northeast of the Leeward Islands and moving west at 17 mph (28 kph) late on Tuesday. Its top sustained winds had strengthened to 65 mph (100 kph) and were expected to reach hurricane strength of 74 mph (119 kph) on Wednesday.