WASHINGTON (AFP) - Gaston became the third hurricane of the Atlantic season on Thursday (Aug 25) when it was upgraded from a tropical storm, the United States-based National Hurricane Centre said.

Swirling in the middle of the Atlantic Ocean some 1,955km west of Cape Verde, Gaston appeared to pose no immediate threat to land. Data collected by the agency's hurricane-tracking mission indicated maximum sustained winds at 121 kmh, with higher gusts, as Gaston travels in a north-west direction at 27 kmh.

The NHC announced on its website that Gaston had become "the third hurricane of the Atlantic Season", in an updated statement to its last bulletin.

Although the Atlantic hurricane season officially runs from June 1 to Nov 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.

Earl became this season's second hurricane earlier this month, leaving 45 dead in Mexico.

Last year's number of storms was below average, with 11 tropical storms in the Atlantic, six of which became hurricanes, including two major ones.