Climate change and the future of U.S. May tornado outbreaks

Tornado outbreaks, involving multiple destructive tornadoes in close succession, result from interactions between large-scale atmospheric patterns and mesoscale dynamics. With a warming climate altering atmospheric behavior, the frequency and distribution of outbreak-favorable patterns may change, influencing future risks. Previous studies identified a dominant pattern associated with historic May outbreaks in the United States and demonstrated the ability of a global climate model (MPI-ESM1.2-HR) to reproduce this pattern in historical simulations (1980–2014). Here, we investigate how the simulated pattern evolves in future projections (2065–2100) using the same model and four emissions scenarios. Across all scenarios, the favorable atmospheric pattern for May tornado outbreaks increases in frequency and expands northward and eastward beyond its historical geographic focus in the Great Plains and southeastern U.S. Consequently, future U.S. May tornado outbreak risks are projected to increase across the eastern U.S., emphasizing the need for adaptive preparedness strategies in a warming climate.