Nick Fetty | September 18, 2014

A new study by the Department of Land Resources and Environmental Sciences at Montana State University found that peak tornado seasons are occurring about two weeks earlier in parts of ‘tornado alley’ compared to six decades ago.

The study examined tornado activity in Kansas, Nebraska, Oklahoma, and northern Texas from 1954 through 2009. Current peak tornado activity generally occurs from early May to early July. The study found that the peak of the tornado season in the 1950s occurred an average of seven days later in the year compared to now. When the data from Nebraska is removed the difference is nearly two weeks.

The researchers hope to use their findings to better prepare for future tornadoes, however, they are left scratching their heads as to what is causing this shift. Record keeping for tornadoes in the United States did not begin until the 1950s and because of this scientists are unable to study longer term trends of tornado activity.

The shift in the timing of the tornadoes can be attributed various factors such as the land’s topography as well as climate and it is difficult to pinpoint a single cause. Climate change has also been named as a possible contributing factor, as meteorologist Greg Carbin points out: “If winters are not as cold, or if spring times are warmer, the location of the jet stream is most likely displaced north of where it has been in the past.”

Although not included in the study, portions of Iowa are often considered part of ‘tornado alley.’ A 2012 list compiled by weather.com ranked Iowa sixth in the nation based on tornadic activity. According to data from ToradoHistoryProject.com, there were approximately 2603 tornadoes resulting in 85 fatalities in Iowa between 1950 and 2013.