Another round of torrential rain and flash flooding came Saturday for parts of the South and Midwest already heavily waterlogged by days of severe storms that also spawned deadly tornadoes. Forecasters warned that rivers in some places would continue to rise for days.

At least 16 people are believed to have died after tornadoes, heavy rain and flash flooding battered parts of the South and Midwest in the United States. Among them was a 9-year-old boy, who was swept away while walking to a school bus stop in Kentucky on April 4.

Two people were killed in Tennessee, officials said, and millions of people were under severe weather advisories and more than 300,000 customers had lost power.

Tornadoes are expected to touch down in parts of the U.S. South on Friday, from northeastern Texas and southeastern Oklahoma into western and central Arkansas.

The tornado watch includes 15 counties in Southeast Texas, and will stay in effect until 9 p.m. Saturday evening. A few tornadoes are possible.

Clouds increase across parts of North Texas Tuesday, leading to partly cloudy and mostly cloudy skies. The southeast surface flow will increase the moisture content throughout the day, and then by late Tuesday, showers and storms will develop. Several First Alert Weather Days are in place for multiple rounds of rain and storms in the forecast.