Tornado Damage Investigation - Greensburg, Kansas (2007)
On the evening of May 4, 2007, “supercell” thunderstorms formed across portions of the Midwestern United States, spawning tornadoes in several States. According to the National Weather Service, an intense supercell developed southwest of Greensburg, KS that evening, resulting in the formation of 12 tornadoes. The purpose of this report is two-fold: to provide a preliminary “ground-truth” of the new Enhanced Fujita (EF) Scale wind speed classification system and to document the damage caused by the tornado. The tornado that struck Greensburg was the first EF5 tornado occurrence since the EF Scale was implemented and thus provided an opportunity to compare the wind speeds derived through use of the EF Scale (observed damage) with wind speeds calculated through material failure analysis. Comparing the newly implemented EF Scale to a material failure analysis provides a data set that helps to build a body of knowledge about the accuracy of the scale.