The 10th tropical storm of the Atlantic hurricane season gradually strengthened as it followed a course that could threaten the Lesser Antilles in two or three days. At 6 a.m. EDT today, Tropical Storm Joan was centered near 12.2 north latitude and 50.8 west longitude, or about 575 miles east of Barbados, moving west-northwest at 15 mph, the National Hurricane Center said. The system has maximum sustained winds of 50 mph with some stronger gusts, according to the center. Little change in strength was expected today, and Joan was expected to maintain the same speed and direction for the next 24 hours, the center said. Joan, first spotted by satellite late last week in the mid-Atlantic, was upgraded from a depression to a tropical storm Tuesday. Tropical storms are named when sustained winds reach 39 mph and hurricanes when winds hit 74 mph. Four hurricanes have formed this season, including Hurricane Gilbert, which killed more than 300 people and caused billions of dollars damage as it ravaged Jamaica, the Cayman Islands and Mexico. The hurricane season runs from June to November.
