A busy stretch of severe thunderstorms is underway due to record heat and now the threats are ramping up, putting major metro areas from Chicago to Nashville under threat as the country hits the peak of tornado season.

The strong tornado threat Thursday includes Chicago, Milwaukee and a big chunk of central Wisconsin. Evansville, Indiana is at the heart of Friday’s tornado threat.

A more active severe weather pattern is getting underway in the Midwest and Plains that could produce large hail, wind damage and a tornado threat into early next week.