A severe thunderstorm outbreak is likely to unfold late Tuesday into Wednesday or Thursday from the Central Plains to the Ohio Valley. Significant damage could occur from wind gusts or tornadoes in Kansas City, Oklahoma City, Tulsa, Chicago, St. Louis, Louisville, Memphis and Dallas before the storm system slows down in the Tennessee Valley and mid-South to end the week. Flooding rainfall is expected in parts of the mid-Mississippi Valley. Here’s what you need to know.