Tropical Storm Isaac strengthened slightly as it headed towards the Caribbean island of Hispaniola early Friday, but seemed unlikely to gain enough strength to hit the Dominican Republic and Haiti as a hurricane. In Haiti, Isaac was threatening thousands of people still living in tents after a devastating earthquake more than two years ago. The storm also posed a threat to the southeastern U.S. state of Florida, where it could pass near the state's gulf coast on Monday as the Republican National Convention begins in Tampa. Authorities have not ruled out the possibility of postponing or relocating the Republican convention if the storm directly hits Tampa, but Craig Fugate, the director of the Federal Emergency Management Agency (FEMA), said the convention was not his biggest concern.
