Data Indicates Tornado Alley is Moving to the East and South

Posted: April 28, 2022 11:23 am

Even the most casual weather observer is familiar with the term Tornado Alley. This large swath of land in the central U.S. is where the most tornadoes have historically occurred over time. However, some weather experts are claiming that this area of land is now shifting to the east. What factors go into this shift and why do climatologists believe this movement is happening? Read on for more information.

Original Tornado Alley

According to the Storm Prediction Center (SPC), approximately 1,200 tornadoes rip through the U.S each year. Although these funnels can happen at any time and in nearly any area, there is a higher risk of the twisters developing in an area defined as Tornado Alley. This term got its start in 1952 after two experts in the field spent time studying and documenting tornadic activity in Texas and Oklahoma. The term has stuck around since that time, however, the so-called alley was expanded to include parts of Kansas, Nebraska, and South Dakota as well as a large portion of Oklahoma and Texas.

Data Points to Shift

In recent years, it would appear as if the normal tornado patterns are moving to the east and south, taking more twisters into areas east of the Mississippi River with greater frequency. The number of tornadoes touching down in areas to the south and east of the traditional area has increased over the years, causing weather experts to re-evaluate this terminology.

A recent study demonstrated that more tornadoes were popping up in the Mississippi Valley over the last 20 years than the number recorded in the area originally defined as Tornado Alley. In addition, the number of days featuring the necessary weather and atmospheric conditions needed to spawn tornadoes has actually declined throughout much of Tornado Alley. Conversely, the fuel for these tornadoes is increasing in the area east of the Mississippi River.

A paper from February 2022 showed that the number of large tornadic events has also shifted to the east in the years 1989 through 2019 when compared to the period between 1950 and 1980. The core of the activity has also moved to the south at the same time that it moved to the east, putting a greater chance of impact throughout the Gulf Coast region and the lower Mississippi River Valley.

Why is the Shift Happening?

There are a few reasons that scientists believe this shift to the east and the south is happening with greater frequency. The long-term drought currently impacting the Southwest is leading to a lack of moisture in the air over the original Tornado Alley. This dry air positioned over the Plains shoves the usual storm track to the east, sending the greatest chance of outbreaks into the Mississippi and Tennessee Valley. Without the necessary moisture to fuel the storms, the pattern will simply move to where these ingredients are in ample supply.

In addition, sea-surface temperatures are increasing in the Gulf of Mexico. This is creating more moisture above the ripe Mississippi and Tennessee Valley. Not only does this increase in moisture help to provide the framework for storm development, but it also raises the risk of hurricanes in this region. Because tornadoes are often born out of tropical weather events, it makes sense that those areas of the U.S. that are seeing an uptick in tropical storm and hurricane landfalls will also experience an increase in tornadoes.

Vulnerability of the Southeast

One of the most concerning aspects of this shift is that there are pockets of the Southeast that are more vulnerable to tornadoes than some of the communities scattered in the original Tornado Alley hotspot. Due to a higher level of poverty and a greater presence of trailer homes, the southeast corner of the nation is more likely to see significant home damage and casualties when tornadoes carve a path in populated areas.

Additionally, the original Tornado Alley is home to some of the most sparsely populated communities in the U.S. In most cases, a tornado could be on the ground for miles and only tear through deserted farmland. This is not the case in more populated areas of the Southeast. Simply put, this shift to the south and east puts millions of more Americans at risk than when the storms were positioned over the largely empty farm fields of the Plains and Midwest.

Lastly, the higher incidence of tornadic activity in more populated areas makes it more difficult for storm chasers to collect data. A lack of data can translate to a shorter warning time.

Despite the changing nature of the storms and their locations, weather experts are quick to point out that these twisters can strike anywhere. This makes it important all families and businesses understand the risk and how to best prepare for a tornado outbreak. A little planning can go a long way in protecting your loved ones and your prized possessions in the event of a tornado.

Did you find this content useful? Feel free to bookmark or to post to your timeline for reference later!

Recent Posts