Tropical Storm Gabriel expected to become 2nd Atlantic hurricane of season. See tracker.

Tropical Storm Gabrielle is expected to strengthen into a hurricane in the evening on Sunday, Sept. 21, as it moves north across the Atlantic Ocean.

The National Hurricane Center said the storm was about 455 miles off the coast of Bermuda on Sunday morning. Currently, the storm is moving northwest at 9 mph with maximum sustained winds of 65 mph.

Forecasters predict Gabrielle could strengthen into a Category 2 hurricane with 100 mph sustained winds within the next 12 hours. It will pass east of Bermuda by Monday, Sept. 22, the NHC said in a 5 a.m. update.

More: 'Ghost town': Atlantic goes quiet at typical peak of hurricane season

No watches or warnings are in effect. While chances of the storm hitting Bermuda are decreasing, dangerous winds and rain are still possible in the area. The NHC warned that residents of the small mid-Atlantic island should be ready to react.