Tropical Storm Ernesto was moving west through the eastern Caribbean Sea with maximum sustained winds of 50 mph Friday night, according to the National Hurricane Center in Miami.
As of the latest update at 11 p.m., Ernesto was moving west at 18 mph about 315 miles south of San Juan, Puerto Rico.
There were no coastal watches or warnings in effect.
Total rainfall of 2 to 3 inches, with isolated amounts of 5 inches, are possible across the lesser Antilles through Friday night, the National Hurricane Center said.
Ernesto was expected to slowly grow somewhat stronger this weekend. It will move across the eastern and central Caribbean during the next 48 hours and approach Jamaica on Sunday, the National Hurricane Center said.