During 2007 – 2015, a total of 2,359 tornado watches were issued by the Storm Prediction Center and 10,840 tornadoes were confirmed. The objective of the first part of this study analyzed the accuracy of tornado watches for the nine-year period of 2007 – 2015. In addition to accuracy, fatalities, lead times, valid watch times, and areas were calculated for each tornado watch. 58.80% of the tornado watches had at least one tornado inside the tornado watch and 27.43% had at least one tornado outside the tornado watch. Of the 10,840 tornadoes, 56.70% were inside a tornado watch, 9.69% were outside a tornado watch, and 33.62% occurred when there was no tornado watch in effect. The average valid time for a tornado watch was 6 hours and 50 minutes and the average lead time for a tornado was 2 hours and 8 minutes. The second objective utilized a survey to determine participant knowledge and better understand “watch severity response”. A majority of the survey respondents accurately identified the difference between a tornado watch and a tornado warning. Most of the respondents described their weather knowledge as ‘moderately knowledgeable,’ ‘very knowledgeable,’ or ‘slightly knowledgeable.’ TV meteorologists, the NWS, and weather apps are the most common sources for daily weather information and information regarding a tornado watch. 81.63% of the respondents correctly identified if they were under a tornado watch during 2016. As the severity of the watch or the length of the activity increased, the likelihood of the respondent continuing the activity decreased. 38.87%, 54.76%, and 79.18% of the respondents ‘probably would not’ or ‘definitely would not’ continue an activity, lasting any duration, during a severe thunderstorm watch, a tornado watch, or a PDS tornado watch, respectively. The final objective attempts to categorize simple economic response to various watch severity types. The percent of respondents who would not continue an activity, based on the severity of the watch, was applied to a variety of watches that occurred during 2016. The economic loss associated with a watch ranged from $498,332.15 – $107,126,919.19.

Tornado warnings are life-threatening situations, and since the public uses television as the main source for tornado warning information, it is important to know how different visuals and messages are influencing the opinions and intentions of people. This research found that participants were more apt to say they would shelter if they were shown a tornado video than a radar video displaying storm-relative velocity or correlation coefficient, while seeing the tornado brought out a heightened level of anxiety and fear. Participants were most influenced by a call-to-action statement spoken by the meteorologist. Participants expressed negative feelings after being asked to both shelter and send in tornado footage at the same time. The standard call-to-action video and one with the addition of viewer-submitted tornado footage were statistically equivalent. Participants more correctly identified the location of a tornado on the radar product explained to them than one that was not.

abstract: Severe weather affects many regions of the United States, and has potential to greatly impact many facets of society. This study provides a climatological spatial analysis by county of severe weather warnings issued by the National Weather Service (NWS) between January 1st, 1986 to December 31st, 2017 for the contiguous United States. The severe weather warnings were issued for county-based flash flood, severe thunderstorm, and tornado phenomena issued through the study period and region. Post 2002 severe weather warnings issued by storm warning area were included in this study in the form of county-based warnings simultaneously issued for each affected county. Past studies have researched severe weather warnings issued by the NWS, however these studies are limited in geographic representation, study period, and focused on population bias. A spatial analysis of severe weather warning occurrences by county identify that (a) highest occurrences of flash flood warnings are located in the desert Southwest and Texas, (b) severe thunderstorm warning occurrence is more frequent in Arizona, portions of the Midwest, the South, and the Mid and South Atlantic states, (c) the tornado activity regions of Tornado Alley and Dixie Alley (i.e. Colorado, Kansas, Oklahoma, Arkansas, Texas, Louisiana, Mississippi, Alabama, Tennessee, and Illinois) contained the highest occurrences of tornado warnings, and (d) the highest instances of aggregate warning occurrences are found in the desert Southwest, the Midwest, and the Southern regions of the United States. Generally, severe weather warning “hot spots” tend to be located in those same regions, with greater coverage. This study concludes with a comparison of local maxima and general hot spot regions to expected regions for each phenomenon. Implications of this study are far reaching, including emergency management, and has potential to reduce risk of life. / Dissertation/Thesis / Masters Thesis Geography 2019

Effective risk communication in the weather enterprise requires deep knowledge about the communities that enterprise members serve. This includes knowledge of the atmospheric and climate conditions in these communities as well as knowledge about the characteristics of the people living in these communities. Enterprise members often have access to data that facilitate the first type of knowledge, but relatively little social or behavioral data on the populations they serve. This article introduces an effort to overcome these challenges by developing a database of community statistics and an interactive platform that provides dynamic access to the database. Specific emphasis is given to one set of statistics in the community database: estimates of tornado warning reception, comprehension, and response by county warning area in the contiguous United States. Exploration of these estimates indicates significant variation in reception and comprehension across communities. This variation broadly aligns with tornado climatology, but there are noticeable differences within climatologically comparable regions that underline the importance of community-specific information. Verification of the estimates using independent observations from a random sample of communities confirms that the estimates are largely accurate, but there are a few consistent anomalies that prompt questions about why some communities exhibit higher or lower levels of reception, comprehension, and response than models suggest. The article concludes with a discussion of next steps and an invitation to use and contribute to the project as it progresses.

The 2019 Dallas Tornado struck a densely populated area, was the costliest tornado in Texas history, and had minimal warning lead time, yet there were no serious injuries or fatalities. To understand why, this study examines individuals' decision-making processes during this tornado using the protective action decision model (PADM). Specifically, it investigates the factors affecting threat belief and evaluation, the facilitators and impediments to protective action, and the effects on future risk perception and hazard adjustment measures. Semi-structured telephone interviews were conducted with 23 survivors to explore their experiences and decision-making processes during this tornado. Interviews were analyzed through inductive coding and a constant comparative approach. Key findings of this study suggest that clear and direct warning messages, coupled with rapid, heuristic-driven reactions, can overcome the impediment of a short-fuse warning time and motivate those at risk to take protective action. Additionally, this study identifies condominium owners as a housing population with unique needs and impediments in the tornado recovery process. Furthermore, results illustrate how the hazard scenario and contemporary technological culture nuance protective action decision-making and future hazard adjustment measures.