Extreme chasers Reed Timmer, Joel Taylor, IMAX Filmmaker Sean Casey, and Tim Samaras present their most exciting tornado chasing moments.

Extreme chasers Reed Timmer, Joel Taylor, IMAX Filmmaker Sean Casey, and meteorologist Dr. Josh Wurman present their most exciting tornado chasing moments.

Behind the scenes with cast and crew.

No description available

Reed Timmer and his team take the day off, but when Sean Casey's team scores a victory in Reed's own backyard, the meteorologist vows to chase with a vengeance. Meanwhile, Tim Samaras grows more cautious chasing storms in Kansas.

After failing to find a twister on two consecutive chases, Reed Timmer and the Dominator team are desperate to chase one down. They're even desperate enough to pursue a powerful storm into an urban area after dark, one of the most dangerous possible chasing scenarios. Team TWISTEX's truck threatens to keep them on the sidelines on a promising tornado day. While team Dominator pursues an intercept, the TIV team is hoping to finally shoot their first ever 3D tornado footage... but tension in the vehicle has everyone on edge, and the crew is finding out that the only thing worse than having a chase ruined by the slick, Texas mud is to be helpless in the path of a tornado.

In the wake of the deadly and very large tornado outbreak (April 27, 2011), all three chase teams take time to help with the recovery effort. Team Tiv is in Smithville, Mississippi and Team Dominator and Team Twistex are in Tuscaloosa, Alabama. Motivated by the death and destruction they've witnessed, all three teams are rededicated to improving warning times and doing vital research on these deadly storms. Team Dominator fields a new, improved vehicle: the Dominator 2 and tracks a storm right toward one member's childhood home. Team TWISTEX outfits their truck with a brand new probe and a mobile Doppler radar, but mechanical issues threaten to sideline them again. Team TIV adds a mobile tornado siren and chases toward the heart of a twister to warn people while shooting 3D twister footage.

On the first chase of the year, there's a storm headed toward downtown St. Louis. While Tim Samaras and his team chase too close to the beast, Reed Timmer's team is on the verge of falling apart.

Reed, Sean and Tim take on the strongest tornado conditions of the season, and nature responds with twisters too close to home.

This special features interviews and documentary footage with the show's production crew, explaining how they accompany the storm chasing teams and the difficulties they encounter working under intense conditions. It shows the main camera angles too.

On the last chase of the season, Reed Timmer's team chases a monster tornado for a radar intercept, and Tim Samaras' team has one last chance to deploy their probe in its path.

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.

Team Dominator risks everything to warn people in the path of a violent storm, but internal conflicts causes driver Joel to leave, complicating Team Dominator's operations. Still gun shy after witnessing devastation this season, Sean Casey starts to lack the passion of chasing storms, until a visit from his wife and a successful chase reignites Team TIV's fire. Team TWISTEX tries to brave the elements by chasing a tornado through a hail storm, but after their vehicles suffer damage, Tim has to swallow his pride and abandon the chase.

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.

After the worst tornado in his life, Reed pursues a new force of nature in TV weather woman Ginger Zee. But chasing more than weather leaves teammates out in the cold. As twisters rip through the Ozarks, one long-time chaser calls it quits.

The DOW Team's in chaos as a broken radar sends Josh scrambling to fix it. Reed jumps on the opportunity to scoop the science team once again, while Danny and Aaron struggle to escape a ditch before a tornado gets too close.

Reed steps up his science to take on Dr. Josh Wurman's massive research project. Joel has second thoughts. The fallout reaches Sean, who makes a drastic decision.

Both Tim Samaras and the TIV team face off with a dangerous tornado. Reed pushes too close, and finds no place to hide.

Tornado season erupts early in Oklahoma. Reed gets his new Dominator too close. Tim chases multiples, and Sean battles a rain-wrapped monster.

The deadliest tornado of the season tears a hundred mile path across Mississippi, destroying 600 homes and the town of Yazoo City. For Reed, Joel and Chris, an epic chase turns into a race to save lives, and changes their own lives forever.

A tornado outbreak threatens to wreak havoc in Reed Timmer's backyard. Sean Casey's team follows their navigator's bold prediction, and tension threatens to derail Tim Samaras' chase on a huge day.

Sean and Reed face off at the New Mexico border. Monster tornados break up everything in their paths, except the tension.

Reed and Joel bury the hatchet to face a new tornado season, but armor offers little protection when the roof blows off the new Dominator. Sean mixes up his crew and unleashes tension in the path of a west Texas twister.