Fierce Hurricane Ike weakened as it charged across the Atlantic on Friday and took aim at south Florida and the oil fields of the Gulf of Mexico, while Tropical Storm Hanna buffeted the Carolinas after killing at least 529 people in Haiti.
Hanna was expected to be just short of Category 1 hurricane strength when it crosses the U.S. East Coast near the North Carolina and South Carolina border early on Saturday, the U.S. National Hurricane Center said.
Nevertheless, authorities declared states of emergency, several North Carolina beach communities were under evacuation orders, campgrounds were shut and storm alerts were issued from Georgia to New Jersey, including for Washington, D.C., as the eighth tropical storm of the Atlantic hurricane season pulled away from the 700 far-flung islands of the Bahamas.
Ike was far more threatening.
An extremely dangerous Category 4 hurricane on the five-step Saffir Simpson scale on Thursday, it weakened a notch to a Category 3 with top sustained winds of 115 mph (185 kph), the Miami-based hurricane center said.
By 8 p.m. (0000 GMT Saturday), it was spinning 315 miles (510 km) north-northeast of Puerto Rico and was expected to sweep westward over the Turks and Caicos Islands and the southern Bahamas by Sunday.
The Bahamian government sent soldiers and emergency supplies to Mayaguana and San Salvador, southern islands left short of food and water by an overdue mail boat.
"If we have heavy flooding and lose power, we could be in an uncomfortable situation," said chief councilor Earnel Brown of the island of Mayaguana.
Some further weakening was possible but the hurricane center said Ike was expected to remain a "major" storm of Category 3 or higher.
Ike's track was riddled with uncertainty.
The hurricane center's official forecast took it through the Florida Keys island chain as a ferociously destructive Category 4 hurricane into the Gulf of Mexico, where around 4,000 offshore platforms produce a quarter of U.S. crude oil and 15 percent of the energy-hungry country's natural gas.
Visitors were ordered to evacuate the Keys on Saturday and residents were ordered out beginning on Sunday.
Some computer models took Ike near the heavily populated Miami area in southeast Florida, where up to 1.3 million people could be ordered to leave the coast.
"It's a lot coming at us. But we must remain vigilant, focused and calm," Florida Gov. Charlie Crist said.
A Category 4 hurricane strike on Miami would be a huge disaster because of the billions of dollars of vulnerable real estate in low-lying islands like Miami Beach and along the coast of the Florida peninsula. Power would be out for millions of people for an extended time.
TRIO OF THREATS
Tropical Storm Josephine churned weakly in Ike's wake across the Atlantic, with 40-mph (65-kph) winds as it spun about 725 miles (1,160 km) west of the Cape Verde Islands.
The trio of Atlantic storms followed Hurricane Gustav's rampage through the Caribbean to Louisiana, where it came ashore on Monday west of New Orleans, largely sparing the city devastated by Hurricane Katrina three years ago.
The flurry underscored predictions for an unusually busy six-month hurricane season. An average season has 10 tropical storms, of which six strengthen into hurricanes with top sustained winds of at least 74 mph (119 kph). Josephine was already this year's 10th, and the statistical Sept. 10 peak of the storm season still lies ahead.
While Hanna did little damage in the Bahamas and posed only a moderate threat to the U.S. East Coast, the death toll in Haiti was rising steadily as the floods unleashed by its torrential rains began to recede.
Police Commissioner Ernst Dorfeuille said 495 bodies had been found in the mud-heaped port city of Gonaives, where thousands survived by climbing on rooftops. That brought the toll for all of Haiti to at least 529.
Ships and planes had begun to arrive with desperately needed aid for Haiti, which has been hit by three deadly storms in less than a month.
By 8 p.m. (0000 Saturday GMT), Hanna was 200 miles (320 km) south-southwest of Wilmington, North Carolina. It was racing north at 20 mph (32 kph) with top winds of 70 mph (115 kph).
Hanna roiled the ocean off North and South Carolina with 18-foot (5.5-metre) waves. Sunny skies gave way to showers and breezy conditions on North Carolina's Outer Banks where residents tested power generators and tied down trash cans and beach chairs.
"It's a little breezy but not any more than a normal rainy day," said Lisa Bell, a manager at Howard's Pub and Restaurant on Ocracoke Island, where the pirate Blackbeard once sailed.
The storm was expected to strike at high tide, bringing a 5-foot (1.5-metre) storm surge likely to cause moderate coastal flooding, and heavy rains were expected far inland.