In 2013 the number of tornadoes in Missouri increased by 70%, and the number of severe tornadoes tripled. It sounds dramatic, but it may be just part of the normal variability involving these terrible storms. I published my initial analysis of tornadoes nationally and in Missouri a year ago with data from 1950-2012. This post updates the information with data from 2013. Look here for my first post, which contains background information about tornadoes.

Missouri has a significant history with tornadoes. Over the last 10 year, Texas led the nation in the average number of tornadoes per year (142), with Kansas second (116), and Missouri third (61). The first map at right shows the data.

(Click on map for larger view.)

Texas, Kansas, and Missouri are geographically large states, however. The second map at right shows the average number of tornadoes per 10 sq.km. of land area for each state for 1991-2010. Kansas is first ( it was second in the data I looked at last year). Florida is second (it was first last year). Some other states surprisingly high on this list include Maryland and South Carolina.

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Missouri is also one of only two states with 8 or more tornado deaths per year over the last 10 years. The third map at right shows the data.

Tennessee leads the nation in this sad statistic with 10, Missouri is second with 8, and the states tied for third have half as many as we do. Missouri has been hit by 3 of the 10 deadliest tornadoes in history. The damage caused by a tornado depends not only on the size of the tornado, but also whether it hits a populated area, whether it hits when people are awake and able to take shelter, and whether buildings are built to withstand the storms. We don’t have statewide building codes in Missouri, consequently there are many buildings that will not withstand a tornado and that have no place of refuge.

The nation had only one EF5 tornado in 2013, the tornado that devastated Moore, Oklahoma, a suburb of Oklahoma City. Initial reports overestimated the number of fatalities, with final estimates putting the number of deaths at 24. This compares favorably to the Joplin tornado, which killed 158. Oklahoma has a state building code.

Missouri’s most severe tornadoes in 2013 were 3 EF3 tornadoes. Two of them hit May 31 and tracked across the St. Louis metropolitan region, causing 2 injuries. The other hit northwest of Sikeston in Southeast Missouri, and tracked eastward through farmland.

Sources:

For the Moore, Oklahoma tornado: I have been unable to find an official casualty count from a government source. Several news sources seem to agree that the count was 24, the number of names on the list of casualties published by the coroner’s office, with many more injured. For a general article on this tornado, see “2013 Moore Tornado,” Wikipedia, viewed 6/27/2014 at http://en.wikipedia.org/wiki/2013_Moore_tornado.

For the Joplin, Missouri tornado, a general article is available at: “2011 Joplin Tornado,” Wikipedia, last viewed 6/27/2014.

For the Harvester and South Roxanna tornadoes of 2013: National Weather Service Weather Forecast Office, St. Louis, MO. Severe Thunderstorms Produce Straight Line Wind Damage and Nine Tornadoes. May 31 2013. Viewed 6/27/2014 at http://www.crh.noaa.gov/lsx/?n=05_31_2013.