SANTO DOMINGO (Reuters) - Hurricane Irene swept just north of the Dominican Republic on Monday after pummeling Puerto Rico, and forecasters saw the storm strengthening to a major hurricane off the Southeast US coast by the weekend. The US National Hurricane Center's forecast showed the first hurricane of the 2011 Atlantic season swinging up Florida's east coast on Thursday for a possible landfall in South Carolina early on Saturday. Irene, the ninth named storm of the busy 2011 Atlantic season, could be the first hurricane to make landfall in the United States since Ike savaged the Texas coast in 2008.