Newly formed Tropical Storm Gaston could become a hurricane on Tuesday or Wednesday as it swirls in the Atlantic far from any coast, US forecasters said.
Gaston, which became a tropical storm only Monday, is located 450 miles (725 kilometers) southwest of Cape Verde, and is not posing any costal watches or warnings, according to the Miami-based National Hurricane Center.
Unlike former tropical storm Fiona, which was downgraded to a tropical depression on Sunday and continues to dissipate farther northwest in the Atlantic, Gaston is strengthening.
"Gaston is forecast to become a hurricane Tuesday night or Wednesday," NHC said in its latest bulletin, posted late Monday.
The storm is traveling northwest at 18 miles (30 kilometers) per hour with maximum sustained winds of 40 mph.
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.
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.