The United States is on pace this year for the lowest number of tornadoes in recorded history, the National Oceanic and Atmospheric Administration reports.
Through late October, there were just over half as many tornadoes as average, and 110 fewer tornadoes than the prior record-low. Very few tornadoes occur during late fall and winter, so it is unlikely sufficient tornadoes will occur by the end of the year to miss setting the full-year record.
The 2013 tornado season continues a long-term trend of declining tornado frequency and severity. NOAA data dating back to 1950 show tornado activity peaked in the early 1970s and has been declining ever since. The strongest tornadoes, those rated F3 and higher, underwent the most dramatic decline during recent decades.
Models Keep Failing
The ongoing decline in tornado activity highlights a rift between real-world data and government-funded computer models predicting rapidly rising temperatures and more extreme weather events such as tornadoes.
In September, a study utilizing computer models programmed by government-funded scientists indicated—contrary to real-world observations—global warming would increase tornado activity.
“There now is considerable evidence that the occurrence and intensity of climate extremes have been increasing in recent decades, and that continued global warming likely will amplify these changes,” the study claimed.
Tom Harris, executive director of the International Climate Science Coalition, said the decline in tornadoes—and especially of strong tornadoes—is no accident. Warming is most pronounced in the polar regions, Harris explained, which reduces the temperature differential between the poles and the tropics. This pronounced temperature differential drives extreme weather events, Harris observed, and when it decreases, it reduces the frequency and severity of extreme weather events such as tornadoes.
James M. Taylor ([email protected]) is managing editor of Environment & Climate News.