AOSC Seminar by Dr. Kelsey Malloy, 05/1/2025
AOSC Seminar
Kelsey Malloy
University of Delaware
Title
Understanding Evolving Climate Variability and Risk for Severe Convective Storms
Abstract
Severe convective storms — thunderstorms that produce damaging winds, large hail, and/or tornadoes — are increasingly becoming a dominant driver of insured losses. In particular, tornado outbreaks — when several tornadoes happen in a short time span — are rare yet impactful events. Observation-based estimates of tornado outbreak risk are limited. To address this gap, we developed a two-part stochastic tornado outbreak index for the contiguous United States. The first component produces a probability map for outbreak tornado occurrence based on spatially-resolved values of convective precipitation, storm relative helicity, and convective available potential energy. The second part of the index provides a probability distribution for the total number of U.S. tornadoes given the outbreak tornado probability map. Together, these two components allow stochastic simulation of location and number of tornadoes that is consistent with environmental conditions.
In this talk, I will present the development of the tornado outbreak index and show how we used it to generate a synthetic event set for U.S. tornado outbreaks. I will highlight applications for investigating climate-scale influences, e.g. El Niño-Southern Oscillation and long-term trends, on outbreak activity. Finally, I will discuss how the index supports event attribution of climate change influence on recent tornado outbreaks, providing an additional line of evidence to observational reports as well as physical context. Overall, these advances help build a clearer picture of evolving climate-related risk for severe convective storms.
Bio
Dr. Kelsey Malloy is an Assistant Professor within the Department of Geography and Spatial Sciences at University of Delaware. Dr. Malloy’s research focuses broadly on climate variability and dynamics, weather and climate interactions, climate risk, and subseasonal-to-seasonal predictability and prediction. Her recent work includes understanding climate-related risk of weather extremes and how teleconnections might change in a warming climate. Dr. Malloy received her Ph.D. in Atmospheric Sciences from University of Miami and her B.S. in Atmospheric and Oceanic Science from University of Maryland.
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AOSC Seminar
Pre-seminar refreshment: N/A
Seminar: 3:30-4:30pm, Room: ATL 2400(only when in-person)
Meet-the-Speaker: 4:30-5:00pm, Room: ATL 3400(only when in-person) [For AOSC Students only]
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