Additional rounds of torrential rain will continue to trigger widespread, life-threatening and catastrophic flash flooding centered on the mid-Mississippi and Ohio valleys into Saturday night, meteorologists say.

Another round of torrential rain and flash flooding has come for parts of the South and Midwest already heavily waterlogged by days of severe storms that also spawned some deadly tornadoes

On Sunday at 12:56 a.m. the National Weather Service issued a flash flood warning in effect until 4 a.m. for Colbert, Franklin, Lauderdale and Lawrence counties.

Flash flood warnings have been issued for part of North Texas, as heavy rain and thunderstorms hit the area Saturday morning. The warnings are in effect for Collin, Dallas, Denton, Lamar, Tarrant and Rockwall counties until 8:30 a.

Just a small percentage of flood alerts issued by the National Weather Service each year are the highest level called a flash flood emergency warning. They typically signal a damaging, life-threatening event is ongoing or imminent and immediate action should be taken.

On Sunday at 12:28 p.m. a flash flood warning was released by the National Weather Service in effect until 3:30 p.m. for Elmore, Lowndes and Montgomery counties.

The NWS Fort Worth TX issued a flash flood warning at 4:42 a.m. on Saturday in effect until 7:45 a.m. for Dallas and Tarrant counties.

Rivers rose and flooding worsened across the U.S. South and Midwest, threatening communities already waterlogged and badly damaged by days of heavy rain and storms that killed at least 18 people.