I made a Blog post a little while ago after Illinois reported their first January tornadoes in over 50 years, and pondered what that might mean for the 2008 severe weather season. Then along came January 10th, last Thursday, and the Southeast, specifically Mississippi and Alabama, got blasted with severe weather including several EF3 tornadoes – at least four, two solely in Mississippi, one crossing from Mississippi into Alabama, and one solely in Alabama.
So I thought it might be a worthy exercise to take a look at some historical statistics to see if anything jumps out.
April has the highest number of tornadoes in Alabama while August has the least number. January falls eighth in the number of tornadoes.
Do January tornadoes tell us anything about the upcoming year? Apparently not. Alabama experiences about 5.5 percent of all tornadoes in a year in January. The last time Alabama saw an EF3 (or F3) or higher tornado in January was in 1988 – and the year ended up with only 16 tornadoes. Before that, there was an F3 in 1975 – and 1975 ended with 36 tornadoes. Other years with F3s in January included 1974 with 39 for the year, 1972 with 13 for the year, 1964 with 27 for the year, and 1953 with 23 for the year. That data sample is very small, I know, but it does not suggest that January strong tornadoes mean much in terms of how many we have throughout the rest of the year.
The average number of tornadoes each year in Alabama since 1950 is 26. However, using data from 1950 includes a significant amount of time when reporting was not very good. If you look at a running average of tornadoes by year for 20 years, the state average is probably between 30 and 35. Even 20 years ago, reporting was not nearly as good as it is today.
This discussion certainly underscores one very important point. Achieving an accurate report on tornado events is critical. Spotter reports during an event become crucial information in the warning decision process. But accurate historical data is important, too, so that we do not underplay or overplay the dangers we face from the weather.
No one knows what the rest of 2008 will bring especially since our severe drought seems to be continuing. And the historical record doesn’t seem to shed any light for a clue as to what we can expect.
-Brian-
