How do El Nino and La Nina affect tornado activity in the Southeast United States?
The connections between El Nino/La Nina events and tornado development over the Deep South are not clear cut. However, preliminary research indicates a relationship between El Nino and the occurrence of strong to violent tornado outbreaks over the Southeast United States. In the case of F2 and greater tornadoes, more appear to occur during La Nina months. La Nina seasons are normally associated with warmer than average temperatures in the South, producing a sharper frontal zone between warmer air and the normally cold arctic air to the north. During this time, Deep South weather is more unstable and colliding air masses set the stage for more tornadoes. A study of the top 15 tornadic outbreaks (at least 40 tornadoes) showed that only one outbreak occurred during an El Nino event. Six occurred during a La Nina event, while the remaining eight occurred during neutral ENSO years. Click here for the current El Nino status and forecast from the National Weather Service Climate Prediction Ce
