ATLANTA (NEXSTAR) — Some schools in the South were closing Wednesday as residents in several states brace for the possibility of intense tornadoes that travel for miles and hail the size of baseballs.

The Storm Prediction Center has issued a rare “High Risk”‘ of severe weather, warning storms could produce intense tornadoes. The center warns of “numerous tornadoes, several intense and long track, scattered damaging winds, some hurricane force…Scattered large hail, some baseball size.”

At highest risk is a region that includes parts of Arkansas, Louisiana, Mississippi, Alabama and Tennessee. That area is home to more than 8 million people and includes Memphis, Tennessee; Birmingham, Alabama; Little Rock, Arkansas, and Jackson, Mississippi.

Parts of Texas and Oklahoma are also at risk of severe storms.

A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building.

Residents should stay tuned to NOAA Weather Radio,, or other media for watches and warnings.

The Associated Press contributed to this report.