Relationships between teleconnections and tornado activity in the southeastern United States

Abstract

In the last couple decades, tornado activity and societal exposure in the Southeastern United States has increased. Given the vulnerability of this region, it is important to explore the possible contributors to tornadogenesis in order to develop predictive models of seasonal and subseasonal tornado activity. While El Niño/Southern Oscillation (ENSO) holds predictive skill in determining heightened tornado activity in some seasons, it does not account for all the variability and often interacts with other teleconnections. This study examines the relationships between monthly tornado counts and four teleconnections: ENSO, North Atlantic Oscillation (NAO), Pacific-North American Oscillation (PNA), and the Arctic Oscillation. This study finds month-to-month variability between single teleconnections and tornado activity. Also, other teleconnections besides ENSO (i.e., PNA, NAO) show potential as the best predictor for above or below normal tornado activity in the SE and the predictability of tornado activity in the SE is greatest from March through October.