Isaac strengthens into a hurricane in the Atlantic Ocean and could cause dangerous waves

Isaac strengthened Friday into a hurricane in the open waters of the Atlantic Ocean and could cause dangerous waves in parts of Bermuda , forecasters said.

The storm was about about 980 miles (1,577 kilometers) east-northeast of Bermuda and about 1,175 miles (1,890 km) west of the Azores, with maximum sustained winds of 75 mph (121 kph). It was heading east at 12 mph (19 kph).

There were no coastal watches or warnings in effect, but the waves could cause life-threatening surf and rip current conditions in Bermuda, the Miami-based U.S. National Hurricane Center said.

Potentially dangerous waves also could spread to the Azores, the center said. Isaac is expected to strengthen before gradually weakening by the end of the weekend.

The storm has been churning in the ocean as Hurricane Helene made landfall in northwestern Florida as a Category 4 storm before weaking early Friday, leaving behind flooding, damage and power outages.