Heavy rain from the thunderstorms may lead to isolated instances of flooding and a "short-lived tornado" is also possible.
Suspected tornadoes also were reported overnight in various parts of Alabama, including Highland Lakes, Greystone and American Village in Shelby County and lake Purdy at Grants in Jefferson County.
At least one mobile home was destroyed, throwing a man from the mobile home.
Over the weekend, four people died in Texas, two in Louisiana, one in MS and another in Alabama.
The forecast of severe weather forced officials at the Masters in Augusta, Ga., to begin the tournament early Sunday, starting threesomes off the first and 10th tees on the day's final round in hopes of finishing in midafternoon before the winds and rains begin. The children were pronounced dead at the scene.
Warm air enhanced the atmosphere's instability Saturday, allowing the storm system to rev up more energy and grow, CNN meteorologist Chad Myers said.
In Mississippi, authorities said there was one storm-related death in Monroe County.
"The storm is so vigorous that tornadoes are still possible after dark", Myers said.
Trees were pulled from the ground by their roots and the tornado caused structural damage to buildings including tearing off roofs.
The National Weather Service was sending a survey team to Alto on Sunday to confirm if the storm was, indeed, a tornado. Homes were damaged about 250 miles (402 kilometers) to the north in Glencoe, and there's scattered damage south of Birmingham.
The biggest threat with the storms will be damaging winds with the possibility of a tornado. No injuries were reported, and news footage showed shattered windows and rooftop debris.
Davis said the strong winds and downed trees that were reported in several counties were likely caused by a very strong squall line, a narrow band of thunderstorms. The parents in the front seats were not hurt.
The National Weather Service of Fort Worth went on to rate the tornado an EF-3, with 140 miles per hour winds.