This NOAA satellite image taken early Friday shows a mass of clouds east of the Bahamas associated with Tropical Storm Otto, which later gained hurricane strength. ((NOAA/Associated Press))

Hurricane Otto has reached hurricane strength over the Atlantic on a path that's expected to take it farther out to sea.

Otto has maximum sustained winds Friday near 120 km/h. The U.S. National Hurricane Center in Miami said some additional strengthening is expected but Otto is forecast to weaken by late Saturday.

A day earlier, raging floodwaters from then-Tropical Storm Otto overturned cars, toppled power lines and washed out roads in the northeastern Caribbean.

Otto is located about 715 kilometres south of Bermuda and is heading east-northeast, away from Caribbean islands, near 17 28 km/h.

The Hurricane Center predicts the storm will advance across the open Atlantic toward the Azores archipelago off Portugal.