Emergency management officials in the Carolinas coast began full preparations Tuesday morning for the possible landfall later this week of a powerful Hurricane Irene. While National Hurricane Center meteorologists wrestled with a complicated atmospheric situation that will steer Irene along or into the U.S. coast, authorities weren't taking chances. Officials on Ocracoke Island along the Outer Banks issued a mandatory evacuation order for all non-emergency personnel, saying people must be off the island by Thursday. South Carolina Emergency Management Division spokesman Derrec Becker said evacuation orders could be issued Thursday, if the Hurricane Center decides Irene is headed for the Palmetto State. He said Gov. Nikki Haley and Emergency Management Director George McKinney are watching the situation closely. But North Carolina is the predicted area of landfall. The latest update from the National Hurricane Center, issued at 11 a.m., nudged the predicted landfall site a bit farther east, near Morehead City. Earlier today, meteorologists had been predicting a Wilmington hit. Either way, Hurricane Irene is expected to have 115 mph sustained winds when it reaches the North Carolina coast. At the state level, spokesman Ernie Seneca of the N.C. Department of Crime Control and Public Safety told the Associated Press that officials were taking inventory of food and water supplies "in case it comes to that point where we have to provide that to people who suffer losses or have to be evacuated." Meteorologists have shifted the expected landfall site of Hurricane Irene several times since Monday morning, from Charleston to Myrtle Beach and now to Wilmington. They said Tuesday morning that the changes probably are not finished -- and that the predicted path could be moved east or west. Hurricane Irene was moving west-northwest Tuesday morning, but forecasters expect a turn to the northwest and eventually the north. That would keep the storm well off the Florida coast and also at least 100 miles off the South Carolina coast. "The biggest uncertainty we have is the timing of the turn to the north and eventually the northeast," said Bill Reed, director of the National Hurricane Center. "In terms of where it's going to go, there is still a pretty high level of uncertainty," said Wallace Hogsett, also of the Hurricane Center. "It's a very difficult forecast, in terms of when it's going to turn northward." At 11 a.m. Tuesday, the center of Irene was at 20.5 degrees north latitude and 71.0 degrees west. That center was 70 miles south-southeast of Grand Turk Island, and the storm was moving to the west-northwest at 12 mph with 100 mph winds. Hurricane warnings were in effect for the Turks and Caicos islands, and for the central and southeast Bahamas. A hurricane watch was issued for the northwest Bahamas. Forecasters say the Bahamas stand to feel the worst of the hurricane, as it is predicted to intensify to Category 4 status -- with 135 mph winds -- by the time it reaches the northern Bahamas on Thursday. A trough, or weakness in the atmosphere, is forecast to allow the hurricane to curve northward by Thursday and make a beeline for the Carolinas coast. But, meteorologists added, if their forecast is wrong, Irene could move inland farther south on the coast - or do the opposite, and curve back out to sea. The storm's expected impact on the Charlotte region lessened considerably as Irene's predicted path was moved eastward. If it makes landfall near Wilmington, forecasters say the area of heavy rain probably will remain east of U.S. 1. Charlotte might get nothing more than breezy conditions and a light shower or two. Areas to the west of Charlotte could see clear skies. South Carolina has not been hit by a hurricane since 2004, and the last major hurricane in North Carolina was Isabel, in 2003. The Ocracoke Island evacuation order was issued because officials on the 16-mile-long island said they wanted to make sure that people had enough time to take the ferry back to the Outer Banks before ocean conditions got rough. Meteorologists say winds and surf will start increasing near the Outer Banks by late Friday. In New Hanover County, near where the storm is predicted to make landfall, Emergency Management Director Warren Lee said he has sent a note to agencies that respond to storms, reminding them to review their "continuity of operations" plans -- the worst-case scenario plans that enable them to operate after electricity and other services are disrupted. Lee said generators were being prepared, and officials were making sure the emergency operations center was ready. In Craven County, emergency management services director Stanley Kite suggested that people planning to leave the area should head west of Interstate 95. Kite said the county's departments are ready to go, and his advice for county residents, "I would suggest they have their evacuation routes ready." Farther to the north, Dare County officials said they were ready. "All the plans we have are in place," said Sandy Sanderson, the emergency management director. "All the people are in place. We are primed and ready to move if we have to." Joe Farmer, of South Carolina's Emergency Management Division, said the state's residents will get plenty of warning. "If it does move this way, there will be a lot of public notice given, and people will be warned," he said. In Horry and Georgetown counties on the S.C. coast, officials said they were ready. Sam Hodge, of Georgetown County Emergency Management, said officials have met with county leaders and school officials about what the school system would do -- including the possibility of postponing high school football games on Friday night. "We're waiting to see what happens," Hodge said. Randy Webster, of Horry County's emergency management operations, said Irene "could be dangerous. We just want people to recognize the threat." South Carolina officials said they have plans ready, in case large-scale evacuations are required. The (Myrtle Beach) Sun News and the Associated Press contributed.