Are tornadoes increasing in both intensity and frequency, or could skewed historical data lead to false conclusions?
This question has vexed climatologists and P&C insurers alike amid the escalating reports of twisters when compared to the previous 15 to 20 years. But researchers at Florida State University (FSU) may have answers, thanks to a model they developed to more accurately gauge tornado risk.
The pioneering researchers provide an overview of the model in “The Decreasing Population Bias in Tornado Reports across the Central Plains,” an article in Weather, Climate, and Society, an academic journal published by the American Meteorological Society. In addition to outlining the methodology, the team offers a plausible explanation as to the discrepancy in confirmed reports: namely, a population bias, coupled with the proliferation of storm chasers and recreational risk-takers roaming Tornado Alley.
Having long suspected that tornadoes were traditionally underreported in rural areas especially, James B. Elsner (a geography professor at FSU) and fellow co-authors—Lauren E. Michaels (graduate student), Kelsey N. Scheitlin, an assistant professor at the University of Tennessee at Knoxville, and Ian J. Elsner, a graduate student at the University of Florida—say the perceived uptick in tornado activity is deceiving.
“Most estimates of tornado risk are probably too low because they are based on the reported number of tornadoes,” Elsner says. “Our research can help better quantify the actual risk of a tornado. This will help with [enhancing] building codes and emergency awareness.”
More data is readily available today, partially because storm of advances in reporting technology, including mobile Internet and GPS navigating systems, along with greater public awareness.
The Science of Tornadoes
It's also important to note that this new research will help propel the scientific exploration of tornadoes, Elsner explains. "The science of tornadoes can move forward to address questions related to whether cities enhance or inhibit tornadoes,” he says.
The model corrects assumptions about reporting in urban and rural areas and, for the most part, dispels the notion that tornadoes are occurring with greater frequency. However, researchers add that some evidence portends more powerful (and therefore destructive) tornadoes.
"The risk of violent tornadoes appears to be increasing,” Elsner said in a statement, citing the tornadoes in Oklahoma City on May 31 and the 2011 tornadoes in Joplin, Mo., and Tuscaloosa, Ala.
The Oklahoma City tornado on May 31, 2013, was the largest tornado ever recorded, with a path of destruction measuring 2.6 miles in width. The Tuscaloosa and Joplin tornadoes are two of the deadliest and most expensive natural disasters in recent U.S. history.