Wednesday's live blog: Multi-day tornado outbreak continues

A potent storm system is increasing the risk of severe thunderstorms, including tornadoes for more than 56 million people on Wednesday. This severe weather threat spans from central Texas, across the central Mississippi Valley, to the lower Ohio and Tennessee valleys, and into the Carolinas.

This video shows more of the damage in Columbia, Tenn. With storms pushing south into Alabama and Georgia, the threat will continue overnight.

Aerial views show severe tornado damage in Columbia, Tenn. Roofs have been ripped off and trees toppled by the powerful winds. The tornado also crossed I-65.

A group in Maury County in Tennessee fled after seeing a large tornado on the horizon. This was the same tornado that prompted the tornado emergency earlier.

A flash flood emergency is happening right now in northern Middle Tennessee. This is a life-threatening situation in this area and residents are encouraged to seek higher ground.

Severe storms are ongoing across the Mid-South. Click here to learn how to turn on your Weather & Radar app alerts.

A large violent tornado is on the ground near Spring Hill, Tenn. A tornado emergency has been issued. Those in this area need to take shelter now.

New images of the tornado damage in Coopertown, Tenn., are coming in. More severe storms are moving through now, keep up with them on the WeatherRadar.

A particularly dangerous situation (PDS) in Missouri as a confirmed tornado continues to move through the Aurora area.

Images are coming in of the tornado that was confirmed north of Nashville earlier today. We'll continue to bring you the latest updates.

The storms have become stronger and more numerous during the last hour. Hail has been reported and even a tornado was confirmed just north of Nashville within the last hour.

Our certified meteorologist Mary Mays is live tracking the severe storms moving along the Tennessee and Ohio valleys. Watch live below.

Storms are ramping up across St. Louis and will continue to move to the east-southeast. Our WeatherRadar shows cloud coverage diminishing but likely poses a bigger threat later on as the heat makes the atmosphere more unstable for more severe storms in the latter part of the afternoon into the evening.

A tornado watch has been issued for southern Missouri, including for the cities of Joplin and Springfield, southern Illinois, and western Kentucky at least until 7 p.m. local time. More tornado watches will continue to be issued in the coming hours across northern Tennessee.

Weather will deteriorate quickly in the afternoon, make sure to stay put in a safe place and have several ways of receiving weather alerts.

It´s been quite a busy week and it will the severe weather continues on the move. A record number of tornado warnings have been issued so far, according to Iowa Environmental Mesonet.

Storms erupted across parts of the Midwest on Tuesday, with tornadoes reported across Michigan, Indiana, and Ohio. The driver of this severe weather was the same system that brought deadly tornadoes to Oklahoma on Monday night.

WeatherRadar is active with the first line of storms moving across northern Tennessee. Flood watches are in effect across much of Tennessee and Kentucky. There are some flash flood warnings in effect for counties north of Nashville.

Another round of strong to violent, long-tracked tornadoes is in the works. Confidence is high enough that the forecasters at the Storms Prediction Center have issued a moderate risk, level 4 out of 5, for parts of southeastern Missouri, northern Tennessee southwestern Kentucky, and extreme southern Illinois.

Close to 4 million people are under this risk as highly populated cities like Nashville will likely be experiencing the worst weather.