Changes in the distributional characteristics of environmental parameters commonly associated with severe weather between the two 15-year periods were used to explore how the frequency/intensity of HCW may change in an anthropogenically forced climate. Given the peak frequency of these events over the region occurs between May and August, changes were explored on both a monthly and seasonal basis. To focus on changes when convection was more likely to occur, environments were only included in the analysis if a model simulated storm was present nearby in the domain. Unlike earlier studies which have focused on the produce of Convective Available Potential Energy (CAPE) and 0-6km deep layer shear, other parameters typically used to characterize favorable severe thunderstorm conditions were also included, such as lapse rates, lifted condensation level (LCL), helicity and composite parameters such as the Significant Tornado Parameter and the Supercell Composite Parameter.
Large increases in CAPE are found between the two 15-year periods, with the largest increase occurring at the 90thpercentile. While changes in helicity are less robust and more variable throughout the domain, the frequency of model simulated storms exceeding an updraft helicity threshold of 60 m2s-2and a composite reflectivity threshold of 45 dBZ increased by more than 35%. Evaluations of model performance also suggest that the high-resolution model is emulating the effects of the Great Lakes on environmental parameters with skill, allowing for further assessment of the role that these large bodies of water could play in moderating or enhancing climate impacts on HCW events and environments. Through the use of high-resolution dynamically downscaled climate data and thorough analysis of numerous HCW proxies and environmental parameters, this presentation will provide an in-depth look into the future of HCW in an anthropogenically altered climate.