The Storm Chasers take to the field in a fleet of customized vehicles, each with its own special role to play in the overall mission of filming tornadoes and collecting severe weather data. The most formidable are the pair of TIVs (Tornado Intercept Vehicle), heavy armored juggernauts designed for direct tornado intercepts and close-in IMAX filming. The newest heavyweight is the DOMINATOR based on the 2008 TVN vehicle but now with an armored shell and other upgraded features. Joining the chase in 2009 is Team Twistex with its lead PROBE vehicle. The DOW (Doppler on Wheels) carries a mobile weather radar system to track tornado activity on the road. Finally, the fleet includes three types of smaller support vehicles that extend the range of the chasers and carry out supplemental weather data collection.