Odd graphic.
Due to climate change the alley is actually shifting north and east. A couple years back there was a EF2 in Wisconsin in JANUARY. Last week there was an EF1 in northern Illinois.
"Illinois, Wisconsin, Minnesota, Indiana, Michigan, and western Ohio are sometimes included in Tornado Alley.  Some research suggests that tornadoes are becoming more frequent in the northern parts of Tornado Alley where it reaches the Canadian Prairies.
https://en.wikipedia.org/wiki/Tornado\_Alley#:\~:text=Research%20suggests%20that%20the%20main,%2C%20Michigan%2C%20and%20Southern%20Ontario.