Interesting Alabama Tornado Stats

With the recent double round of tornadoes in Alabama which has set a new record for the most tornadoes in a single February, my curiosity was piqued about how many times a single month has seen 20 or more tornadoes. I found the results both amazing and somewhat startling!

I’m talking about tornado events since 1950. Data before 1950 is not very good since there was little effort to collect data on tornado events. Sure, there is a good deal of data on big events like March, 1932, but in general the tornado data is not very complete. In fact, I’m sure that the data from the 1950s is probably not too good either, but you’ve got to draw the line in the sand somewhere, and 1950 is as good a point as any.

First, I thought there would be a lot of months with 20 or more tornadoes. Boy, was I wrong. There have only been 11 months from 1950 through 2007 in which 20 or more tornadoes were reported. That’s 11 months out of a possible 696 months in that time period – that’s less than 2 percent!

Okay, so 11 times there were 20 or more tornadoes in a month. So probably most of those occurred in the peak months of March, April, and May. Well, not exactly. Five (5) of the 11 months were in the peak season, two were in the secondary season, and four were in other months with tropical systems! This is not too startling.

So here they are in my list:
1. Nov., 2001 36
2. Mar., 1976 26
3. Nov., 2004 25
4. Apr., 2006 24
5. Sep., 1998 23
6. Sep., 2005 23
7. Aug., 1985 22
8. May, 2003 22
9. Feb., 2008 21
10. Mar., 1996 20
11. May, 1984 20

Interesting, perhaps, that the highest four alternate between the peak season and the secondary season.

Perhaps another somewhat startling fact is that the super outbreak of April, 1974, did not result in a month with 20 or more tornadoes – it actually came in with 18 tornadoes.

I’m sure someone will latch onto the fact that many of these large monthly totals have come in the last 20 years or so. That must mean that tornado events are increasing. But I don’t subscribe to that theory. I think that with population increases, wider distribution of the population, and greater awareness, fewer and fewer tornadoes are going unreported. A good example of this came just yesterday when a National Weather Service survey team stumbled upon tornado damage from about a month earlier while surveying damage from the day before.

Well, back to the spreadsheets – I’m sure there is another gem to be found in them thar numbers somewhere!!

-Brian-

Category: Uncategorized