A tropical depression threatened Florida and parts of the southeastern United States with severe thunderstorms after being upgraded to Tropical Storm Colin by the U.S. National Hurricane Center. The storm, expected to hit Florida’s Gulf Coast by Monday afternoon, began drenching parts of the southeastern United States on Sunday. Forecasters warned of severe thunderstorms along the East Coast and issued a tropical storm warning for Florida’s Gulf Coast. Colin is the second named storm in a week at the beginning of what is expected to be a brisk Atlantic Ocean hurricane season running through Nov. 30.