The climatology, vulnerability, and public perceptions associated with overlapping tornado and flash flood warnings in a portion of the Southeast United States

Abstract

Simultaneous and overlapping tornadoes and flash floods are a meteorological hazard with complex societal implications as, when issued at the same time, tornado and flash flood warnings provide conflicting public safety advice. This work assessed potential tornado and flash flood (TORFF) events in a portion of the Southeast from an interdisciplinary perspective with a focus on the climatology, vulnerability, and public perceptions surrounding these hazards. In addition to the conflicting warning advice, TORFFs present a challenge to the public because they can occur at night or in cool seasons, when they are least expected, though they are most common in spring. Also, the storms causing the TORFFs are often not clearly organized, causing a forecast and communication challenge. The public responding to the tornado and flash flood warnings in our study area is more vulnerable to TORFFs than those in other areas, and may lack vehicles and structures to respond safely to one or both hazard threats. Administered survey results suggest that many believe they know what protective actions to take in a TORFF, though they may not believe they are likely in their area. Those that believe they are likely are also more likely to feel prepared to respond. Many climatology and vulnerability characteristics vary between, and at times within, NWS County Warning Areas, highlighting the different communication and preparation needs across the region. Approximately a quarter of flash flood and tornado warnings overlap in the region, for an average of 31 minutes. The frequency of TORFFs and their associated public safety challenges warrant continued investigation.