"What makes a supercell unique from all other thunderstorm types is that it contains a deep and persistent rotating updraft called a mesocyclone. If the environment is favorable, supercell thunderstorms can last for several hours," NWS said.

Memphis is under a tornado watch and a flash flood warning as winds and up to 4-6 inches of rain are expected, according to the National Weather Service.

Parts of the Midwest and South are facing the possibility torrential rains and life-threatening flash floods on Friday The fresh storms come as many communities are still reeling from severe tornadoes

The National Weather Service said 45 river locations in multiple states were expected to reach major flood stage, with extensive flooding of structures, and roads.

At least six people have been killed in a wide swath of violent storms and tornadoes that hit the South and Midwest

Parts of the Midwest and South faced the possibility of torrential rains and life-threatening flash floods Friday, while many communities were still reeling from tornadoes that destroyed whole neighborhoods and killed at least seven people.

Torrential rains and flash flooding battered parts of the Midwest and South on Friday, killing a boy in Kentucky who was swept away as he walked to catch his school bus. Many communities were left reeling from tornadoes that destroyed entire neighborhoods and killed at least seven people earlier this week.

Flooding is inundating Nashville as Middle Tennessee weathers a seemingly endless string of severe storms. State of play: Heavy rain made several roads throughout the region impassable on Thursday. Floodwaters temporarily closed major arteries,

After an active night with numerous tornado and severe thunderstorm warnings, our late morning and early afternoon hours Thursday will see a brief lull in severe weather potential. A Tornado Watch is in effect for a good portion of Middle Tennessee and parts of Southern Kentucky through 10 p.