NWC REU 2018
May 21 - July 31



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Assessing Central Oklahoma's Tornado Risk: The May 24, 2011 Tornado Outbreak

Justin Bonds, Ashton Robinson-Cook, Amber Davis, and Mark Shafer


What is already known:

  • Tornado climatologies suggest that Norman has a similar strong/violent tornado risk as surrounding municipalities despite being spared the worst of these impacts.
  • Past studies have used population data to determine that increasing population density in urban areas are increasing the likelihood of an urban tornado disaster.
  • In past studies, county level population data was used to compare recent and historical outbreaks, although the higher resolutions of census track data is preferred for studying a single tornadic event.

What this study adds:

  • This study has shown that the use of high-resolution damage surveys of tornadoes can be used to effectively assess central Oklahoma’s tornado risk.
  • These simulations provide insights into population exposure and potential impacts from a regional tornado outbreak on local areas
  • This study sets the foundation for additional detailed catastrophe modelling studies
  • Furthermore, we can use potential population exposure rates to to have high confidence casualty rate statistics.


In this study, we looked at central Oklahoma’s vulnerability, population exposure, and casualty estimates during a historical tornado outbreak. The event studied was the May 24, 2011 tornado outbreak that occurred over parts of central and western Oklahoma. GIS was used to perform an analysis of the outbreak. We found that we can use past tornado outbreaks to show potential severe weather risks. We also found that casualty statistics for counties can be estimated based on generated simulations and actual statistics calculated from the tornado outbreak. Lastly, We can have high confidence in these simulations effectively showing potential risk for an outbreak, with simulation population exposures showing numbers significantly higher than the actual exposure, as well as county confidence intervals showing the potential for some counties to be impacted multiple times by tornadoes.

Full Paper [PDF]