Hurricane Irene pounded the Bahamas with winds of 120 miles (195 kilometers) an hour and churned up heavy seas as it barreled along a path toward the populous US east coast. The storm became a major category three hurricane, fueled by warm waters in the Atlantic, and spread over a wide area as it swirled over the sprawling archipelago of the Bahamas, picking up intensity. US satellite images showed Irene churned past the Dominican Republic and meteorologists said its tropical force winds extended out some 230 miles (370 kilometers). The US National Hurricane Center in Miami said Irene, the first hurricane of the Atlantic storm season, was expected to become a category four storm with winds of 135 miles (217 kilometers) per hour. It said the eye of the "dangerous" storm was moving between Rum Cay and Long Island in the Bahamas, in an update at 0001 GMT (Thursday). "My husband already started getting the shutters together, and we're also packing to get out," said Edna Smith, whose house in Holmes Rock, Grand Bahama, was flooded in the last hurricanes in 2004 and 2005. "We're not staying there. We're probably going to a shelter." Deborah Rolle rushed to load groceries in the back of her car in Freeport after making last-minute purchases. "I'm trying to get a jump-start on things, getting everything prepared," she said. The path of the storm raised concerns along the US east coast, and US officials were closely watching for shifts in its track. US forecasters said they expected the eye to come close to Cape Hatteras, North Carolina early Saturday, then continue north over water toward the eastern edge of New York's Long Island on Sunday. Authorities began evacuating tourists from the North Carolinas popular Outer Banks beach resort early Wednesday and have ordered a mandatory evacuation of the Ocracoke and Hatteras barrier islands. "This could be a very large storm, so we are taking it very seriously," said Governor Bev Perdue. Bill Read, director of NHC, said the track remains uncertain but that "the exact center of the storm may stay close to the coast on Saturday and perhaps become a big threat to New England and Long Island." He said the storm had become "very well organized overnight" and was growing in size. "It is in the warmest water and a favorable environment so it could actually get stronger," he told reporters in a conference call. The NHC said that "interests in eastern North Carolina and the mid-Atlantic states should monitor the progress of Irene." Craig Fugate, the head of the US Federal Emergency Management Agency, said emergency personnel were preparing from impact from the Carolinas to New England. "This is going to be a big storm. Just because it hits one area doesn't mean its not going to cause damage further up the coast," he said. "The most important thing for people to do right now is to listen to and follow the instructions of their local officials. If you are told to evacuate, evacuate." Up to 12 inches (30 centimeters) of rainfall were expected in parts of Bahamas and Turks and Caicos, with a "dangerous" storm surge up to 11 feet (3.3 meters) on some islands. Airports and businesses closed Wednesday in the Turks and Caicos, where officials said high winds toppled power lines and spread debris in city streets. White House spokesman Josh Earnest said that President Barack Obama had been briefed on Wednesday on the hurricane during his vacation in Martha's Vineyard, Massachusetts, which coincidentally could be on or near the storm path in a few days. He said officials "are looking at the very detailed logistical effort to ensure that we're going to have the proper resources pre-deployed."