An Analysis of Tornado Warning Reception and Response across Time: Leveraging Respondents' Confidence and a Nocturnal Tornado Climatology.

Nocturnal tornadoes are challenging to forecast and even more challenging to communicate. Numerous studies have evaluated the forecasting challenges, but fewer have investigated when and where these events pose the greatest communication challenges. This study seeks to evaluate variation in confidence among U.S. residents in receiving and responding to tornado warnings by hour of day. Survey experiment data come from the Severe Weather and Society Survey, an annual survey of U.S. adults. Results indicate that respondents are less confident about receiving warnings overnight, specifically in the early morning hours [from 12:00 AM to 4:00 AM local time (0000–0400 LT)]. We then use the survey results to inform an analysis of hourly tornado climatology data. We evaluate where nocturnal tornadoes are most likely to occur during the time frame when residents are least confident in their ability to receive tornado warnings. Results show that the Southeast experiences the highest number of nocturnal tornadoes during the time period of lowest confidence, as well as the largest proportion of tornadoes in that time frame. Finally, we estimate and assess two multiple linear regression models to identify individual characteristics that may influence a respondent's confidence in receiving a tornado between 12:00 AM and 4:00 AM. These results indicate that age, race, weather awareness, weather sources, and the proportion of nocturnal tornadoes in the local area relate to warning reception confidence. The results of this study should help inform policymakers and practitioners about the populations at greatest risk for challenges associated with nocturnal tornadoes. Discussion focuses on developing more effective communication strategies, particularly for diverse and vulnerable populations. Significance Statement: We aimed to understand what time of the day members of the public were least confident that they would receive and respond to a tornado warning. Our results demonstrate that members of the public are not only less confident that they would receive warnings overnight, but they are least confident between midnight and 4:00 AM local time (0000–0400 LT). We then used a climatology of tornado reports to see where tornadoes occur during this time frame. Most of the tornadoes that occur between midnight and 4:00 AM occur in the Southeast, which is troubling because this area also has large numbers of people living in poverty or in less robust structures, like mobile homes. We also show that individual characteristics like age and the number of weather information sources someone accesses impact confidence in one's ability to receive warnings during this time frame. These results should help inform forecasters and emergency managers about the communities that need more time to respond to overnight tornado events. [ABSTRACT FROM AUTHOR]