Some flooding was reported but no major damage though one death in Florida was linked to the storm.

Some parts of the Carolinas saw up to 180mm of rain by Thursday afternoon due to a combination of moisture carried by the cold front that pushed Eta across Florida and moisture from the Gulf of Mexico brought in by the tropical system.

That's led to flash flooding, multiple water rescues and road closures, and at least one collapsed bridge, said National Weather Service meteorologist Sandy LaCourte.

"It's unfortunately been a tough day for the Carolinas today," she said.

Earlier, Eta slogged ashore near Cedar Key, Florida, before moving northeast across the state.

The storm emerged into Atlantic waters early on Thursday afternoon and was forecast to pass just offshore of South Carolina and North Carolina as it races up the Southeast seaboard through Friday morning.

At 4 pm, Eta was 150 km south-southwest of Charleston, South Carolina.

It had top sustained winds of 65 km/h and was moving to northeast at 30 km/h.

Although it was not the most powerful storm to hit the US this year, Eta still had broad impact across the Tampa Bay region, which is home to more than 3.5 million people across five coastal counties.

No mandatory evacuations were ordered but authorities opened shelters for anyone needing them.

Firefighters in Tampa rescued around a dozen people who got stuck in surge flooding.

The storm had meandered in the Gulf of Mexico earlier this week after crossing over South Florida on Sunday.

Eta first hit Nicaragua as a Category 4 hurricane and killed at least 120 people in Central America and Mexico, with scores more missing.

It then moved into the Gulf of Mexico early Monday near where the Everglades meet the sea.

Australian Associated Press