Tropical storm Chantal was weakening as it traveled in the Caribbean Sea Wednesday and may degenerate into a tropical wave, weather forecasters said. Chantal, with maximum sustained winds of 45 mph, was about 260 miles west-southwest of San Juan, Puerto Rico, and about 140 miles south of Santo Domingo, Dominican Republic, moving in a west-northwesterly direction at 29 mph, the National Hurricane Center in Miami said in its 5 a.m. EDT advisory. A tropical storm warning was in effect for the entire coasts of the Dominican Republic and Haiti, Turks and Caicos and the southeastern Bahamas. A tropical storm watch was posted for the central Bahamas. Chantal was expected to maintain its current path with a decrease in speed through Wednesday night. The storm was forecast to shift to a more northwesterly path Thursday. The center is forecast to be near or over Hispaniola later Wednesday and near or over eastern and northern Cuba Thursday. Some weakening is expected during the next 48 hours. Forecasters said Chantal could degenerate into a tropical wave later Wednesday. A storm surge accompanied by dangerous waves will raise water levels by as much as 1- to 2 feet in the tropical storm warning area. Chantal is expected to produce 3- to 6 inches of rain over Puerto Rico, the U.S. Virgin Islands, the southeastern Bahamas, the Dominican Republic and Haiti, with a possible 10 inches possible in some areas.