Sprawling fields turned into large lakes throughout West Tennessee, including in the small town of Halls, where it turned cold and extremely wet.

A Tennessee Department of Transportation crew worked to close state Highway 88 outside Halls, as water began moving over the road that connects US Highway 51 and the Mississippi River.

Forecasters expect more heavy rains in parts of the flood-ravaged south on Tuesday, prolonging the misery for worried people unable to return to homes surrounded by water.

Some of the hardest-hit areas were under a flash-flood watch, as the National Weather Service said as much as 5 centimetres (2 inches) of rain, and even more in some spots, was expected to fall in a short amount of time in central Mississippi.

The national Weather Prediction Center projected the greatest likelihood of heavy rains in a band from eastern Louisiana across central parts of Mississippi and Alabama and into far west Georgia.

Authorities around Mississippi's capital city of Jackson warned hundreds of residents not to return home until they were given an all-clear following devastating flooding on Monday.

The receding flood left muddy water marks on the sides of cars at the Harbor Pines Mobile Home Community in suburban Ridgeland, not far from where managers of the Ross Barnett Reservoir have been trying to contain the swollen Pearl River.

Water still surrounded dozens of trailer homes on Tuesday, even though they had fallen 0.6 metres (2 feet) or more since Monday.

Crews were going lot-to-lot to check the duct work beneath mobile homes to determine how many had been inundated by water.

The power remained off as a precaution and it is still unclear when residents will be able to return.

Meanwhile, on the Gulf Coast, water draining toward the ocean cut off a neighbourhood on the Tensaw River in Baldwin County, Alabama, where residents had to use boats to get to homes, news outlets reported.

The Mobile River is forecast to crest more than 1.2 metres (4 feet) above flood level this weekend north of Mobile.

Alabama Governor Kay Ivey issued a state of emergency that directed state agencies to assist with recent flooding and allowed local school systems where flooding occurred to ask for relief in fulfilling school calendar requirements.

A near-record rainy winter led to agonising choices for reservoir managers, who had to release water that worsens flooding for some people living downstream while saving many other properties from damage.