A tropical storm named Gordon has formed over the Atlantic Ocean and could strengthen into a hurricane at the weekend, US monitors said Thursday, though no coastal warnings or watches were in effect.

The Miami-based National Hurricane Center said in a 0900 GMT bulletin that Gordon was about 585 miles (940 kilometers) east of Bermuda, and was packing maximum sustained winds of 40 miles per hour (65 km/h).

The storm was moving north-north-east at 14 miles per hour and was expected to turn toward the northeast and then east, the NHC said, and it will keep moving over the open waters of the Atlantic for the next two days.

"Some strengthening is forecast during the next 48 hours and Gordon could become a hurricane over the weekend," the bulletin said.