With the storm continuing a hurricane warning is still in effect for most of the Gulf Coast an area stretching from Mississippi's Pearl River to the Alabama-Florida border, with the NHC expecting as much as eight inches of rain to fall and rain likely to continue through to Thursday evening.
The 2 a.m. ET update from the National Hurricane Center said the storm had maximum-sustained winds of 50 miles per hour as it moved northwest at 14 miles per hour.
Gordon formed into a tropical storm near the Florida Keys early Monday as it lashed the southern part of the state with heavy rains and high winds.
In Louisiana, Gov. John Bel Edwards declared a state of emergency Monday and said 200 National Guard troops will be deployed to southeastern Louisiana. However, no major damage or serious injuries were reported, other than the one fatality - a baby in a mobile home, struck by a large tree limb in Pensacola late Tuesday.
Downpours have flooded streets in Louisiana, Arkansas and Mississippi as the storm headed north and threatened to bring heavy rains to the Mississippi Valley and the Midwest over the next few days, the NHC said.
Water levels from storm surge along the Gulf of Mexico will gradually subside Wednesday morning, the NHC said. In Florida and along the Gulf Coast, authorities also warned of possible tornados.
The storm dumped heavy rain through must of the day, drenching parts of South Florida with up to five inches.
Gordon was located about 55 kilometres south-southwest of Mobile, Alabama and was packing maximum sustained winds of 110 km/h, the Miami-based weather forecaster said.More news: The Cranberries singer Dolores O'Riordan was 'drunk when she drowned'
The storm struck along the border of Alabama and MS with winds blowing at up to 70 miles per hour (112 kph), which later eased somewhat. Workers on at least 54 oil and gas production platforms were evacuated.
The storm is expected to strengthen further before it hits land.
More than 35,000 homes and businesses in Alabama and MS were without electricity early yesterday, Poweroutage.us reported. "Sometimes it starts pushing not only water across but debris, logs and things of that nature, which makes it very treacherous to get across", he had said.
MS shut down a dozen Gulf Coast casinos as the storm neared.
New Orleans Mayor LaToya Cantrell said the city has "the pumps and the power" needed to protect residents.
"This is our first time coming out here to the beach for a storm", said Danielle, who added she had also been through Hurricanes Opal and Ivan but didn't do much outside observing for those storms.
NASA's Aqua satellite passed over the Gulf of Mexico and collected temperature information on Tropical Storm Gordon's clouds as it moved toward landfall and after landfall.