Typically, we consider the heart of Tornado Alley to be in the Plains of North Texas, Oklahoma, and Kansas. That was not the case during the past decade.

The 13 Alert Radar network is today's most powerful radar technology. But this summer, the next generation of weather radars is being developed and field-tested in Tornado Alley.

Here’s what you should know about Tornado Alley and why the shift is impacting millions of Americans. An F4 tornado bears down on storm chaser Tim Samaras near Manchester, South Dakota in 2004.