(RNN) – Isaac strengthened into a hurricane Sunday night, hours after Helene, too, became a hurricane. The storms are two of three hurricanes currently spinning in the Atlantic.
Hurricane Isaac is the fifth hurricane of the 2018 Atlantic season. It is currently 1,305 miles east of the Windward Islands, which are in the West Indies, and moving westward at 14 mph.
The storm has sustained winds of 75 mph. It is expected to accelerate during the next 36 hours and head into the eastern Caribbean Sea by Thursday.
Hours before Isaac became a hurricane, Helene strengthened into one. The storm is 195 miles west-southwest of Cabo Verde, an archipelago nation near the African coast.
Helene is moving west-northwest at 13 mph, packing maximum-sustained winds of 85 mph. It's expected to strengthen through Tuesday before beginning to weaken.
The third hurricane in the Atlantic, Hurricane Florence, could pose a danger to parts of the U.S.
The storm is 685 miles southeast of Bermuda, moving westward at 7 mph with maximum-sustained winds of 90 mph – and it's strengthening as it heads toward the East Coast.
The NHC predicts it could become a major hurricane by Monday and remain that way through Thursday.
"On the forecast track, the center of Florence will move over the southwestern Atlantic Ocean between Bermuda and the Bahamas Tuesday and Wednesday and approach the southeastern coast of the United States on Thursday," the NHC said Sunday.
North Carolina, South Carolina and Virginia have declared states of emergency in preparation for the potential impact of Florence.