MIAMI - A weather system in the Caribbean strengthened Friday to become Tropical Storm Ernesto, the fifth named storm in the Atlantic this year.
Parts of Haiti and Jamaica were under a tropical storm watch as Ernesto churned over the Caribbean Sea.
At 2100 GMT the center of the storm was located 485 Kilometers (300 miles) south-southwest of Puerto Rico, packing maximum sustained winds of 65 kilometers (40 miles) per hour, according to the National Hurricane Center.
The center's five-day forecast indicates the storm could blow over Jamaica, cross the western tip of Cuba and then head into the Gulf of Mexico, where coastal US cities are still recovering from the devastation wrought by Hurricane Katrina one year ago.
If the storm follows the forecast track it could gain strength from the warm Gulf waters and turn into a potentially dangerous hurricane.
To date none of the tropical storms that formed in the Atlantic this year have developed into full-blown hurricanes.
Tropical Storm Debby, meanwhile, weakened over open waters in the Atlantic hundreds of kilometers from any inhabited area.
08/25/2006 21:24 GMT