An attempt was made to logically collect and display a series of "tornado outbreak" cases from the past 30 years. The criteria decided on was any event that had a Destruction Potential Index (DPI) of 200 or more. DPI was developed by Thompson and Vescio (1998) as a means of quantitatively evaluating a tornado outbreak. In short, this index numerically describes "the potential for tornado casualties and property damage as a function of tornado intensity, path width, and path length." This page begins with such outbreaks in the 1970s. Subsequent pages contain events from the 1980s, 1990s and the 2000s.

As a side note, the history of tornadoes to affect the Oklahoma City metro area is quite interesting. Mike Branick of the NWS in Norman has compiled a very detailed listing of such occurrences which can be found here. A complete description of this project, including the data collection methodology and statistical graphs can be found on the NWS Norman web site.