Tornado Vulnerability

Structural Forces: Perception and Vulnerability Factors for Tornado Sheltering within Mobile and Manufactured Housing in Alabama and Mississippi

Kevin Ash, Michael Egnoto, Stephen Strader, Walker Ashley, David Roueche, Kim Klockow-McClain, David Caplen, Maurya Dickerson


Southeastern U.S. mobile and manufactured housing (MH) residents are the most tornado-vulnerable subset of the population because of both physical and socioeconomic factors. This study builds upon prior MH resident tornado vulnerability research by statistically and geographically analyzing responses from a survey administered to these residents in the Southeast. Specifically, 257 Alabama and Mississippi MH residents were administered a survey with questions pertaining to their perceived tornado risk and vulnerability, protective action and decision-making, and beliefs about the structural integrity of their homes. Results indicate that, despite the weather and emergency management enterprises consistently suggesting that MH residents evacuate their homes for sturdier shelter during tornado events, more than 50% of MH residents believe their homes are safe sheltering locations. The prevalence of larger MHs in northern Alabama partially influences willingness to shelter within one’s MH, while higher levels of negative affectivity stemming from recent impactful tornadoes in northern Alabama influences people to evacuate their MHs for safety. Study findings also uncovered a perception and vulnerability paradox for these residents: Those who have the means to evacuate their MH often feel they have no need to do so, whereas those who recognize the potential peril of sheltering in their home and want to evacuate often lack the resources and/or self-efficacy to carry out more desirable sheltering plans. Overall, study results provide valuable information for National Weather Service forecasters, emergency managers, and media partners so that they may use it for public outreach and MH resident education.

Finescale Assessment of Mobile Home Tornado Vulnerability in the Central and Southeast United States

Stephen Strader, Walker Ashley


Research has illustrated that tornado disaster potential and impact severity are controlled by hazard risk and underlying physical and social vulnerabilities. Previous vulnerability studies have suggested that an important driver of disaster consequence is the type of housing affected by tornadic winds. This study employs a Monte Carlo tornado simulation tool; mobile home location information derived from finescale, land-parcel data; and census enumerations of socioeconomic vulnerability factors to assess the tornado impact probability for one of the most wind hazard–susceptible demographics in the United States: mobile home residents. Comparative analyses between Alabama and Kansas are employed to highlight regional (i.e., Southeast vs Great Plains) differences in mobile home tornado risk, exposure, and vulnerability. Tornado impact potential on mobile homes is 4.5 times (350%) greater in Alabama than in Kansas because Alabama, in comparison to Kansas, is represented by 1) a greater number of mobile homes and 2) a more sprawling mobile home distribution. Findings reveal that the Southeast’s mobile home residents are one of the most socioeconomically and demographically marginalized populations in the United States and are more susceptible to tornado impact and death than illustrated in prior research. Policy makers, engineers, and members of integrated warning teams (i.e., National Weather Service, media, emergency managers, and first responders) should use these findings to initiate a dialogue and construct interdisciplinary actions aimed at improving societal and individual resilience before, during, and after hazardous weather events.