Chronologically speaking, most of this episode takes place before the previous episode "Tornado Intercept Tank". However, the tornado which the DOW team is shown chasing occurred on April 24, the day after Reed's tornado intercept in the previous episode. DOW's was an EF0 which touched down just south of Stockton, Kansas.
Reed: (teasing Joel about being a pessimist) I continually hear Joel sigh every time say a positive statement, but...
Joel: I'm positive we're not going to see a tornado today.
The construction of the new TIV2 is shown in this episode, and everyone is impressed by its design, certain that it will remain safely intact when hit by a tornado. Before it could prove itself in the field in season 3's intercept, it was tested on an episode of Mythbusters, along with a vehicle Reed Timmer uses in later seasons called the SRV Dominator, to see if they would be able to withstand winds of tornadic force. After a miscue (Sean forgot to lock one of the doors), the TIV2 stood rock solid under a 250 mph wind, the windspeed of an EF5 tornado with only a little bending to the anchoring spikes. A Boeing 747 engine at full throttle was used to simulate the storm winds.