MIAMI (AP) — Isaac strengthened into a hurricane in the open waters of the Atlantic Ocean on Friday and could cause dangerous waves in the Azores, while Tropical Storm Joyce formed and did not threaten the country, forecasters said.

Isaac was about 1,080 miles (1,740 kilometers) west of the Azores, with maximum sustained winds of 75 miles per hour (121 km/h). It was moving in an east-northeast direction at a speed of 29 km/h.

There were no coast watches or warnings for either storm, but Isaac’s waves could cause life-threatening surf and rip current conditions in the Azores, the Miami-based US National Hurricane Center said.

The center had previously said waves could hit parts of Bermuda, but did not include those warnings in a subsequent warning. Isaac is expected to get stronger before gradually weakening by the end of the weekend.

The storm raged over the sea as Hurricane Helene made landfall in northwest Florida as a Category 4 storm before weakening and leaving behind early Friday Flooding, damage and power outages.

Also on Friday, Joyce became a tropical storm. It lies approximately 1,325 miles (2,130 km) east of the Northern Leeward Islands and has maximum sustained winds of 40 mph (65 km/h). It was moving northwest at a speed of about 20 km/h.

The storm was expected to gradually strengthen through Sunday before weakening early next week.