(Reuters) - Tropical Storm Isaac is expected to be a hurricane soon, with significant storm surge and flood threat from rainfall expected along the northern Gulf coast, the U.S. National Hurricane Center said Monday.
The storm was located about 230 miles south-east of the mouth of the Mississippi River, with maximum sustained winds of 70 miles per hour (110 kmph), the NHC said.
Isaac is moving toward the northwest near 10 mph (17 kmph) and this general motion with a slight decrease is forward speed is expected during the next day or so, the NHC added.
Once ashore, the storm could wreak havoc on low-lying fuel refineries along the Gulf Coast that account for about 40 percent of U.S. refining capacity.
(Reporting by Naveen Arul in Bangalore; Editing by Gary Hill)