Impacts of ENSO on Tornado Frequency and Geographical Distribution in the Eastern United States

Tornadoes are a reoccurring severe weather hazard, with the highest rates globally occurring in the central United States. Despite their high occurrence in the U.S., the scientific community’s lack of understanding of their tendencies during varying phases of the El Nino Southern Oscillation (ENSO) is surprising and the topic is clearly in need of further research. In this study, tornado events from 1950 to 2014 in the U.S. states east of the Rocky Mountains will be investigated. A predetermined list of El Niño and La Niña years and intensities derived from the Oceanic Niño Index (ONI) will be utilized to examine the bulk of U.S. tornadoes.  ENSO influences on tornado frequency and geographical distribution will be determined in the region. The overall goal of this project is to determine whether regions of the United States are statisticically more likely to experience a higher frequency of tornadoes during certain phases and intensities of ENSO.