Projected changes to severe thunderstorm environments as a result of 21st century warming in CORDEX-CORE simulations
- 1The Abdus Salam International Centre for Theoretical Physics, Earth System Physics, United States of America (rglazer@ictp.it)
- 2Oak Ridge National Laboratory, Oak Ridge, TN, USA
Dangerous weather related to severe thunderstorms including tornadoes, high-winds, and hail cause significant damage globally to life and property every year. Yet the impact on these storms from a warming climate remains a difficult task due to their small scale and transient nature. Here, we present a study in which the changes to the large-scale environments in which severe thunderstorms form were investigated during 21st century warming (RCP2.6 and RCP8.5) in a group of RegCM CORDEX-CORE simulations. Severe potential is measured in terms of CAPE (Convective Available Potential Energy) and shear during the severe seasons in three regions which are known to currently be prone to severe hazards: North America, the southeastern coast of South America east of the Andes, and eastern India and Bangladesh. In every region environments supportive for severe thunderstorms are projected to increase during the warm season months in both RCP2.6 and RCP8.5 during the 21st century. The number of days supportive for severe thunderstorms increases by several days per season over the vast majority of each region by the end of the century. In the case of RCP2.6, where greenhouse gas forcing is relatively weak compared to RCP8.5, there is still a consistent positive trend in the impact on severe days. The simulations using RCP8.5 forcing show large changes to the annual cycle of severe weather as well as the number of days supportive for severe weather per season. In some regions, like for example Northern Argentina along the Andes mountains, the number of days with severe conditions present increases by nearly 100% by the end of the century. Analyzing the CAPE and shear trends during the 21st century we find seasonal and regionally specific changes driving the increased severe potential. 21st century surface warming is clearly driving a robust increase in CAPE in all regions, however poleward displacement of vertical shear in the future leads to the movement of severe environments over North America and South America. We would also like to present a preliminary look at the next phase of this project which will apply similar methods to an ensemble of 11o Euro-CORDEX simulations to investigate severe conditions over the European region in the future.
How to cite: Glazer, R., Torres‑Alavez, J. A., Giorgi, F., Coppola, E., Das, S., Ashfaq, M., and Sines, T.: Projected changes to severe thunderstorm environments as a result of 21st century warming in CORDEX-CORE simulations, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6282, https://doi.org/10.5194/egusphere-egu21-6282, 2021.