Econintersect: Associated Press Science writer Seth Borentstein has reported that the strength of the Moore, Oklahoma tornado on 21 May 2013 dwarfed the “awesome energy of the atomic bomb that leveled Hiroshima”. Just how powerful was this storm? How does it compare historically? Econintersect heard again and again from TV reporters that Tuesday evening that this was the most powerful tornado in history. Is that true?
There is a wealth of data on many tornado metrics for more than a century at Wikipedia. Selected data is presented as part of the following discussion.
The deadliest tornadoes in Canadian and U.S. history are listed in the following tables. Of the ten deadliest tornadoes, only the 2011 Joplin, MO occurred after 1953. Five occurred before 1936 and three occurred before 1900. The strength of the tornadoes may not be well represented by the fatality numbers; advanced warning, better preparation, even as population densities increased dramatically, have probably mitigated loss of life as the years advanced.
Click on tables for larger image.
The death toll for the 21 May tornado in Moore OK is far from making this list. It is far from making the top 25 list (25th is 80 in Udall, KS 25 May 1955).
A 2001 paper in the American Meteorological Society Journal: Weather and Forecasting, February 2001 has data on the damage of the 30 costliest tornadoes in U.S. history. The data is given in 1997 dollars.
Click on table for larger image.
For reference, 2013 dollars are obtained with multiplication of 1997 dollars by 1.45 (using CPI, Consumer Price Index). That puts the cost in current dollars for the 03 May 1999 Oklahoma City tornado at $1.4 billion. That tornado hit almost the same area in Moore as this week’s twister.
The 2011 Joplin MO tornado damage was valued at $2.8 billion a year after the event. Early estimates of damage in Moore is of the order of $2 billion according to many reports on TV. Many of these TV sources are the same that were reporting this was the most powerful tornado in history, so be advised of how tentative the $2 billion estimate should be considered.
At any rate, as bad as the event this week is, it seems clear that it may well not be the “worst tornado” or the “most powerful” in history. But for the U.S. it is certainly very close to the most powerful and damaging, although not with respect to loss of life.
For another point of reference, according to Wikipedia, more than half of the global tornado fatalities have occurred in Bangladesh, including one that took more than 1,300 lives.
Sources:
- Normalized Damage from Major Tornadoes in the United States: 1890–1999 (Harold E. Brooks and Charles A. Doswell III, American Meteorological Society Journal: Weather and Forecasting, February 2001)
- Tornado records (Wikipedia)
- Damage from Joplin, Mo., tornado: $2.8 billion (Associated Press, San Fransisco Chronicle, 20 May 2012)
