Tornado droughts in central Alabama

ARE “QUIET” TORNADO YEARS RARE IN CENTRAL ALABAMA?

We all remember the severe weather experienced across Central Alabama in 2011. During 2011, Central Alabama experienced a record number of tornadoes with seventy eight occurring in the Birmingham Weather Forecast Office’s area of responsibility. Most of those occurred during the two memorable outbreaks in April, with the first occurring on the 15^th and the second on the 27^th. However, things have been relatively quiet in regard to tornado activity across Central Alabama since 2011. In fact, only thirteen tornadoes occurred in Central Alabama in 2013, with the last one occurring on April 11^th. This began a relative tornado “drought” across Central Alabama which lasted over ten months and ended on February 21^st this year, when an EF-0 tornado occurred in St. Clair County. But is such a drought unprecedented in Central Alabama?

Since 1950, there have been ten years when less than ten tornadoes have occurred, and eleven years when only between ten and fifteen occurred. On average, during the ten years between 2004 and 2013 thirty nine tornadoes occurred each year across Central Alabama, and in the fifty years between 1964 and 2013 we have averaged eighteen tornadoes per year. So, although Central Alabama normally has a significant number of tornadoes most years, it is not extremely unusual for relatively quiet “tornado” years to occur.

Statewide Tornadoes by Year

What is quite rare, however, is for EF-5 tornadoes to occur in the area. Since 1966, only four tornadoes have produced EF-5 damage in Central Alabama. These occurred on March 3, 1966 in the Vienna and Benevola tornado, April 3, 1974 in the Guin tornado, April 4, 1977 in the Smithfield tornado and most recently April 27, 2011 in the Hackleburg and Phil Campbell tornado.

Finally, in general our records indicate that there has been a general increase in the number of tornadoes since the 1990s. This is likely due, at least in part, to the advent of the Doppler radars in use since that time. Doppler radar has allowed us to better observe storms and identify potential tornadoes that we were not able to “see” with our older “legacy” radars. This, in combination with an increase in reports from storm spotters and the general public through means such as social media, etc., have allowed us to document many tornadoes that in years past might have gone undetected, especially the weaker EF-0 and EF-1 tornadoes.