Tropical Storm Arlene developed Thursday in the northwest Caribbean Sea, moving closer to western Cuba and becoming the Atlantic hurricane season’s first named storm. Gulf Coast residents, such as those in storm-battered Florida, were warned to beware of the possible effects of the storm and were told to keep an eye on its development. The storm had maximum sustained winds of 40 mph after strengthening from a tropical depression Wednesday and it is expected to enter the Gulf of Mexico by Friday.