MIAMI — Weather forecasters say the fourth tropical storm of this year’s Atlantic hurricane season will strengthen as it moves through the Lesser Antilles. The U.S. National Hurricane Center said Sunday that Tropical Storm Dorian could intensify to near hurricane strength over the eastern Caribbean Sea by Tuesday. As of 2 p.m. EDT Sunday, the storm’s center was located around 430 miles (692 kilometers) east-southeast of Barbados and was moving west at 14 mph (23 kph). Maximum sustained winds remained near 40 mph (64 kph). A tropical storm warning was in effect for Barbados. Tropical storm watches were issued for St. Lucia and St. Vincent and the Grenadines. Additional watches and warnings could be issued later Sunday. The advisory says Puerto Rico, the Dominican Republic, and Haiti should monitor the storm’s progress.