After saturating Florida with heavy rains and strong winds, tropical storm Isaac is now on the verge of becoming a hurricane, with significant storm surge and flood threat to the northern Gulf coast, according to the National Hurricane Center (NHC).

The NHC said Tuesday that Isaac's center was about 205 miles south-east of the mouth of the Mississippi River, with maximum sustained winds of 70 miles per hour (110 kmph). The storm was marching toward the northwest at a speed of near 12 mph (19 kmph), Reuters reported.

More updates to follow...