Walker S. Ashley, Andrew J. Krmenec, and Rick Schwantes

American Meteorological Society

Published date April 26, 2008

Vulnerability due to Nocturnal Tornadoes

  • This study investigates the human vulnerability caused by tornadoes that occurred between sunset and sunrise from 1880 to 2007
  • Results illustrate that the nocturnal tornado death rate over the past century has not shared the same pace of decline as those events transpiring during the daytime
  • From 1950 to 2005, a mere 27.3% of tornadoes were nocturnal, yet 39.3% of tornado fatalities and 42.1% of killer tornado events occurred at night
  • Finds that tornadoes during the overnight period (local midnight to sunrise) are 2.5 times as likely to kill as those occurring during the daytime hours
  • Finds that unlike other structure types that show no robust demarcation between nocturnal and daytime fatalities, nearly 61% of fatalities in mobile homes take place at night revealing this housing stock’s distinct nocturnal tornado vulnerability