Tornado deaths: what the past tells us about the future

Brooks and Doswell (2002) looked at the long-term trends in tornado deaths in the United States up through 2000. A sharp decline in the rate of deaths per million population was seen between 1925 and 1995. It wasn't clear at the time whether the decline had stopped in the 1990s. They also identified that mobile home residents were approximately 15-20 times more likely to be killed than permanent home residents and speculated that this fact, combined with the increase in mobile home residents, could lead to a levelling off of the tornado fatality rate. With an additional decade of data since that analysis, it has become clear that tornado fatalities have indeed stopped declining as the fraction of deaths occurring in mobile homes has increased to over 50%. This is at the same time as lightning deaths have continued to decrease.

After reviewing the historical data, I will discuss the limitations to decreasing the number of tornado deaths in the future. It seems likely that improving the quality of warnings would have less of an impact than improving the response to the warnings.

Reference:

Brooks, H. E., and C. A. Doswell III, 2002: Deaths in the 3 May 1999 Oklahoma City tornado from a historical perspective. Wea. Forecasting, 17, 354-361.