The Role of ENSO Diversity in Modulating Tornadic Activity in the United States

Research has shown that El Niño–Southern Oscillation (ENSO) can modulate springtime tornadic activity in the United States. During El Niño, fewer tornadoes occur over the central US due to weakened surface winds and reduced convective potential energy. La Niña conditions increase tornadic activity by enhancing warm moist air advection from the Gulf of Mexico, increasing convective potential energy. However, the diversity within ENSO means different ENSO types can have significantly varied implications for tornadic activity. In this study, we utilized datasets from the Storm Prediction Center’s severe thunderstorm and tornado database and convective available potential energy (CAPE) data from the Copernicus Climate Change Service (C3S) Climate Data Store to investigate how ENSO diversity impacts springtime tornadoes and their development across the United States. Tornadoes were more prevalent across the central plains and parts of the southeast during an central Pacific La Niña compared to a eastern Pacific La Niña. In comparison, El Niño-related tornadic conditions remained generally low and largely confined to the central plains while the southeast experienced more activity during a central Pacific El Niño. CAPE values showed similar patterns, with eastern Pacific ENSO events displaying higher values across the United States compared to central Pacific events. These findings help improve seasonal tornado predictions.