Unpredictable Tornadoes

It’s tempting to think that climate change is bringing more frequent, stronger and larger thunderstorms and accompanying tornadoes, but climate scientists say they just don’t know if that’s the case. Tornadoes and the severe thunderstorms that spawn them are difficult to predict, they say.

“It’s hard to predict future tornado seasons when we don’t understand current tornado seasons,” Harold Brooks, a researcher at the National Weather Center, told the Associated Press during the National Tornado Summit held recently in Oklahoma City.

Similarly, a report published this year by Lloyd’s of London, “Tornadoes, A Rising Risk,” states: “While climate change may have a number of effects on atmospheric conditions favorable to tornado formation, the relatively short and unreliable record of tornado activity makes it difficult to determine a definite trend in tornado climatology. Climate models are currently unable to resolve small-scale phenomena such as tornadoes, and no models exist which can use climate model data to predict future tornado activity.”

With the onset of “tornado season” a few statistical reminders may be in order.

The Insurance Information Institute reports that there were 939 tornadoes in the United States in 2012.

Insured losses resulting from severe thunderstorms, including tornado events, caused cost $14.9 billion in insured losses and $27.7 billion in economic losses last year, according to Munich Re.

The top ten states for tornadoes in 2012 were: Kansas (145); Texas (114); Alabama (87); Mississippi (75); Kentucky (65); Louisiana (53); Nebraska (48); Oklahoma (41); Florida (40) and Illinois (39).

Nearly 1,700 tornadoes were reported in 2011, and total damages from the outbreaks exceeded $25 billion, according to the Lloyd’s report. That number includes the May 2011 tornado outbreak in Joplin, Mo., which caused $2.2 billion in insured losses and resulted in 158 deaths.

Although tornadoes have been recorded on all continents except Antartica, according to Lloyd’s the United States annually has the most tornadoes – around 1,000 on average. The most violent tornadoes also typically occur in the United States.

Lloyd’s reports that Canada has the second most number of tornadoes but far fewer than the United States – about 80 to 100 annually. Additionally, according to Lloyd’s, “Russia may have many tornadoes but reports are not available to quantify their occurrence.”