ATLANTA (AP) - Florence is now a hurricane and forecasters say it could hit the U.S. East Coast as a powerful hurricane next week.
Florence is expected to become a major hurricane by Monday, the National Hurricane Center said, adding that "a rapid intensification" is forecast to begin Sunday. It will continue to remain an extremely dangerous major hurricane through Thursday.
The Miami-based weather center says the storm is forecast to become a "major hurricane" Monday, travel between Bermuda and the Bahamas on Tuesday and Wednesday before approaching the southeastern U.S. coast on Thursday.
Officials in the Carolinas warned residents to prepare and to brace for impact.
At 11 a.m. EDT, the hurricane center said Florence's maximum sustained winds were estimated to be 75 mph. The storm was centered about 750 miles southeast of Bermuda and moving west at 6 mph. A west-northwestward motion with ain increase in forward speed is expected by Monday and will continue through mid-week.
There are no reported coastal watches or warnings in effect. However, the NHC says that swells generated by Florence are affecting Bermuda and are beginning to reach portions of the U.S. East Coast. These swells are likely to cause life-threatening surf and rip current conditions.
Meanwhile, separate from Florence's track, Tropical Storm Helene is approaching islands off the western coast of Africa and is expected to become a hurricane soon. Helene is expected to produce tropical storm conditions for parts of the Cabo Verde Islands on Sunday. A third tropical storm, Isaac, has also formed in the eastern Atlantic Ocean. Isaac is strengthening over the Eastern Tropical Atlantic.
The Associated Press (AP) contributed to this story.