Storm season starts out deadly, and Josh and Sean race to get a bigger, badder Tornado Intercept Vehicle, TIV-2, on the road. Meanwhile, a new force of nature emerges in Tornado Alley as Reed Timmer beats the pros to get incredible tornado intercepts.

Sean's new TIV-2 chases a promising storm, but vehicle parts fly for all the wrong reasons. Reed's team pursues a monster storm as it bears down on the town of Lamesa Texas.

Tensions mount between Sean and Josh, as Reed offers to chase with the TIV. Reed chases a risky nighttime tornado into the hills of Arkansas, while Sean and Josh return to Greensburg, Kansas one year after a twister nearly wiped the town off the map.

TIV-1 makes a heroic return, but the tables turn as a monster EF-4 tornado chases the storm chasers through eastern Arkansas.

With the DOW truck and all the research vehicles functioning once again, the team finds themselves hunting in the same territory as their rival Reed Timmer. Tornadoes are forming all over western Kansas on what looks like the biggest day of the season.

Reed and Josh's teams struggle to find the perfect storm in Nebraska. Reed's girlfriend Jene gets lost in a deadly hailstorm while the DOW team mistakenly drives into an on-coming tornado.

As tornado season comes to a close, Sean has one last chance to get the shot of all shots from inside a tornado, while Reed pushes his team to the edge, getting closer to a twister than ever before.