Deadly Compound Heat Stress-Flooding Hazard across the Central United States

While major advances have been made toward understanding flooding across the central United States, little is known about the linkage between heat stress, characterized by high temperature and humidity, and flooding during the summer in this area. Here, we focus on a compound event that relates these two hazards; we find that a high percentage of floods are preceded by a heat stress event. The potential impacts are significant, leading to overwhelming the current infrastructure (e.g., damaged roads, hospitals, power grid) and to a high number of fatalities and economic damage. We show that heat stress is tied to high surface temperatures, sensible heat flux, and humidity, which all tend to enhance convective available potential energy (CAPE) and stormy weather, frequently resulting in flooding. Given that heat stress is projected to become more frequent and intense, our findings point to an associated enhanced risk of flooding throughout this area.