Hurricane Isaac strengthened overnight to become the fifth hurricane of the 2018 Atlantic season and the third currently swirling towards the United States, joining Hurricanes Florence and Helene.
The Miami-based National Hurricane Center said in their 5 a.m. advisory Isaac was holding steady in strength over the central Atlantic and was moving west at 14 mph.
Isaac is about 1,305 miles east of the Windward Islands with maximum sustained winds of 75 mph. It is expected to accelerate over the next 36 hours.
A westward motion is forecast to continue through the end of the week, with Isaac expected to move across the Lesser Antilles and into the eastern Caribbean Sea Wednesday night or Thursday. Weakening is forecast to begin by the middle of the week.
Isaac has become the fifth hurricane of the 2018 Atlantic season. (National Hurricane Center)
“Isaac is a small hurricane and uncertainty in the forecast is higher than normal,” the National Hurricane Center said. “Although Isaac is forecast to begin weakening when it approaches the Lesser Antilles, it is still expected to be at or near hurricane intensity when it reaches the islands.”
Isaac’s strengthening to a hurricane came just hours after Helene became a hurricane just off the African coast. The storm is about 195 miles west-southwest of Cabo Verge, an archipelago near the African coast.
In the meantime, the Carolinas and Mid-Atlantic states are rushing to prepare for the rapidly strengthening Florence, which is expected to strengthen before it hits the U.S. east coast later this week.
A tropical depression could form later this week when a trough currently over the northwest Caribbean Sea moves over the western Gulf of Mexico, the center said.
The Associated Press contributed to this report.
Lucia I. Suarez Sang is a Reporter for FoxNews.com. Follow her on Twitter @luciasuarezsang