As of 5 p.m., the storm had maximum sustained winds of 70 mph with higher gusts and was located about 95 miles south-southeast of Mobile, Ala., and about 90 miles southeast of Beloxi, Miss.
Authorities are also warning residents about the possibilities of tornadoes over MS and western Alabama as powerful winds remain.
Gordon was forecast to come ashore between 7 pm and 9 pm local time on Tuesday (0000 GMT to 0200 GMT Wednesday) along the Mississippi Gulf coast near the Louisiana state line as a Category 1 hurricane on the five-step Saffir-Simpson scale.
Early Tuesday, Gordon was packing maximum sustained winds of 65 miles per hour - short of the 74-mph threshold for a hurricane.
Gordon's expected to be a quick moving storm with heavy rains and possible tornadoes.
The storm was due to come ashore late Tuesday near the border between Louisiana and MS, and drop as much as 8 inches of rain in areas still recovering from last year's hurricanes.
Dauphin Island, off the coast of Alabama, took a direct hit. Workers on at least 54 oil and gas production platforms were evacuated. The threat from Gordon has greatly diminished across Louisiana, however, scattered showers and storms are still possible overnight and into the morning.
Grand Isle Mayor David Campardelle called for a voluntary evacuation of the barrier island.
The governors of Louisiana and MS have declared states of emergency, and emergency operations centers have been activated from Florida to Louisiana as officials urge residents to prepare for the storm. The storm's predicted track had shifted slightly east, meaning Louisiana is now just outside the area under the hurricane warning.
"Hopefully we get some beneficial rain from that", Drake said.
Meanwhile, New Orleans Mayor LaToya Cantrell warned: "The city's absolute number one priority is to ensure the safety of our residents". New Orleans braced for flooding, but in the end got only a glancing blow.
As Tropical Storm Gordon heads toward the MS coast, we asked if the storm will affect Fort Worth. Hurricane Florence was some 3,900 kilometres away from the US, and lining up behind it, another potential storm was likely to form not far off the coast of Africa.
"It's the peak of hurricane season", Hurricane Center director Ken Graham told The Associated Press.