Statistical Downscaling for Global Relationships between the Climate System and Severe Thunderstorms

Dr. John Allen

Associate Professor, Central Michigan University

Severe thunderstorms are local phenomena found globally, and produce a variety of hazards that include hail, tornadoes, damaging winds, lightning and heavy precipitation. In the present climate, these events produce large losses to property and life. The warming climate is expected to influence these storms, primarily through increasing thermodynamic instability as atmospheric moisture scales with warming near-surface temperatures. However, while a number of studies have explored how the climate system modulates these hazards, the focus has disproportionately favored North America and Europe. This presents a challenge, as many parts of the world that regularly experience severe thunderstorms exist in different climate regimes or latitudes which exhibit non-linear responses to the warming climate. Hence what is known for these regions does not reflect a complete picture of the expected changes to hazards. This presentation will share new insights leveraging low-dimensional statistical approaches to estimate the frequency at which environments favorable to severe convection occur globally through the use of atmospheric reanalyses. How climate models represent these features, and these environments change in response to both climate variability and change as projected using the latest generation of Coupled-Model Intercomparison Project Version 6 (CMIP6) data will also be explored. Through these insights, the presentation will address the importance of international partnerships to emphasize the contributions of local expert knowledge, engaging stakeholders and the sharing of new tools to facilitate generating environmental profiles for vast arrays of data.

Bio: Dr. John Allen is an Associate Professor of Meteorology in the Department of Earth and Atmospheric Sciences at Central Michigan University. Dr. Allen received his B.Sc and Ph.D. from the University of Melbourne, Australia, with majors in Applied Mathematics and Statistics & Atmospheric and Oceanic Sciences. He then moved to the U.S. as a postdoctoral research scientist at the International Research Institute for Climate and Society at Columbia University, before joining CMU. Dr Allen’s research focuses on severe convective storms, including hail, tornadoes and damaging winds, and ways to characterize these phenomena across scales. Dr. Allen is a leading contributor on the influence of the climate system on severe storms, and has been honored with the National Science Foundation’s CAREER award and the AMS STAC Outstanding Early Career Award from the Weather Analysis & Forecasting committee.