Hurricane Gaston picked up strength Sunday as it swirled in the Atlantic east of Bermuda, the US National Hurricane Center (NHC) reported.
Gaston has sustained maximum winds of 90 miles (150 kilometers) per hour, the Miami-based NHC said in its 0900 GMT bulletin.
The center of Gaston was located 620 miles east of Bermuda and was moving towards the northwest at a speed of six miles per hour.
Gaston became the third named hurricane of the Atlantic season on Thursday, but quickly weakened to a tropical storm. It then strengthened and regained its hurricane status late Saturday.
The hurricane was forecast to turn north on Monday, and the NHC's five-day forecast cone has Gaston then moving northeast and into the open Atlantic by Thursday.
The NHC issued no coastal watches or warnings, though it did say that Gaston was expected to strengthen during the next 48 hours.
Gaston's hurricane-force winds extend outward up to 15 miles from its center, and its tropical-storm-force winds extend outward up to 140 miles.
Although the Atlantic hurricane season officially runs from June 1 to November 30, this year's first hurricane -- Alex -- formed in January during an unusual weather event.
The Climate Prediction Center of the National Oceanic and Atmospheric Administration (NOAA) initially estimated the Atlantic would see between 10 and 16 storms this year, but recently updated its prediction to 17.
The eight-week stretch between mid-August and mid-October is the most active period for storms and hurricanes in the Atlantic, according to the NHC.
"The statistical peak day of the hurricane season -- the day you are most likely to find a tropical cyclone somewhere in the Atlantic basin -- is September 10th," the NHC website says.