(NewsNation Now) — Multiple regions could see adverse weather Thursday, with snowstorms in the Midwest and a tornado risk in the South, bringing with it all sorts of hazards.

Powerful thunderstorms, and maybe even tornadoes, are in the forecast for large parts of Mississippi, Alabama and Tennessee on Thursday.

More than 20 million people are in an at-risk zone for severe weather, according to the National Storm Prediction Center. Jackson, Mississippi; Memphis and Nashville in Tennessee; and Huntsville, Alabama, are the places forecasters said are in the most danger.

Thunderstorms in these areas could produce winds as strong as 70 mph, the Storm Prediction Center said. As it gets hotter, the threat of tornadoes will only increase, leading to potential damage and also large hail.

Further north, wintry weather is likely.

The overall storm system has the potential to bring “a swath of disruptive snow and freezing rain to extend from northern Oklahoma to southern Michigan on Thursday,” the National Weather Service warned.

Storm warnings are in effect in Wichita, Kansas City, St. Louis, Chicago and Detroit with four to eight inches in total expected across those zones. Winter storms caused streets in major Kansas and Missouri cities into ice-slicked rinks earlier in the day.

In other areas, it’s not snow but rain people need to watch out for.

Other areas, such as Buffalo, Indianapolis and St. Louis, are seeing heavy flooding rain, although colder air being pulled in behind the system is changing that heavy rain to freezing rain.

Many schools, courts and other governments services, as well as sporting events, throughout the warning area shut down Thursday in anticipation of the storm.