This weekend was a rough one for the Southeast United States from Louisiana to Florida, as I’m sure you have already heard. Severe thunderstorms ripped across the Deep South and Gulf Coast from Saturday morning through late last night leaving a path of devastation in their wakes. So far, 29 tornadoes have been confirmed, and the storms are being blamed for at least 20 deaths.
The question I received today was just how rare are tornadoes in January? The answer is that they are somewhat rare, but they do happen. In fact, when they occur on January 22, it is more likely to be across Mississippi, Alabama, and a portion of southern Tennessee than anywhere else.
The Storm Prediction Center, part of the National Oceanic and Atmospheric Administration, does more than just predict severe weather – they keep records of it as well. The two maps to the right show the probabilities of tornadoes and the probabilities of significant tornadoes for January 22. The records used to create the maps are from 1982-2011, so this weekend’s storms are not yet part of the count.
The Tornado Probabilities map shows that from eastern Texas through southwestern Tennessee over to southwestern Georgia and in central Florida, there is a 0.20% probability that a tornado will occur on January 22.
If you were a betting person and I told you that a horse had a 0.20% chance of winning a race, would you bet on it? My guess is that you would not, unless you just really loved that particular horse. While chances are slim the horse would defeat all the others in the field, there is still a very slight chance that it will win, and if it does, the world would take notice.
On the Significant Tornado Probabilities map, the probability of a tornado with an EF-2+ rating on the Enhanced Fujita Scale are even smaller over that area – less than 0.10%. Now you’re betting on a blind horse, but as long as it’s in the race, winning is possible.
This weekend, the blind not-so-thoroughbred beat the odds. All of the ingredients for a major severe storm outbreak with significant tornadoes came together in late January with sorrowful and devastating effects. It happened in the one area we suspected it would based on our historical data, but that doesn’t make it any easier to deal with for those people affected.