AlQa'dah 27, 1434, Oct 3, 2013, SPA -- Tropical Storm Karen formed in the southeastern Gulf of Mexico on Thursday and was heading toward the U.S. coast between Louisiana and northwestern Florida, the Miami-based National Hurricane Center (NHC) said. Energy companies started evacuating some workers from oil and natural-gas platforms in the Gulf of Mexico on Wednesday. The NHC, using data from hurricane-probing airplanes, said a disturbance in the gulf had organized into a tropical storm with winds up to 100 kilometers per hour (kph). "Hurricane and tropical-storm watches will be issued for portions of the northern gulf coast," forecasters said. Karen was moving north-northwest, and forecast models showed it hitting the U.S. coast along Louisiana, Mississippi, Alabama, and northwestern Florida over the weekend. Locally heavy rain could affect parts of Cuba and Mexico's Yucatan Peninsula in the news few days, the NHC said.