For the past few decades, data shows that Tornado Alley is shifting eastward.

The scientific journal Nature published a study in 2018 that showed there have been more tornadoes in the Mississippi River Valley than in the original Tornado Alley — the nickname for an area with relatively higher instances of confirmed tornadoes.

Created in 1952, Tornado Alley included parts of Texas, Oklahoma, Kansas, Nebraska and South Dakota.

However, according to the National Weather Service, Tornado Alley maps have always been transient. Different iterations of maps can encompass different areas because tornado occurrences can be measured in different ways, including looking at all tornadoes, tornado parish or county segments or strong and violent tornadoes only.

In an article published last year, Scientific American said tornadoes have become more common in eastern Missouri and Arkansas, western Tennessee and Kentucky, northern Mississippi and Alabama, and portions of northern and northeastern Louisiana. AccuWeather’s analysis includes the entirety of northern Louisiana and large portions of central Louisiana.

Tornados can happen in many parts of the world, but about 1,200 occur in the United States a year. Different areas of the country have different “tornado seasons.” The NWS said the Gulf Coast’s tornado season is in the early spring, but they can occur any time of year.

Research shows the shift could be caused by a warming climate and change in the dry line — an imaginary border that separates the “wetter easter U.S. from the drier western U.S.” — movement to the east, according to Scientific American.

Tornadoes are also becoming “fiercer and more frequent.”

A season of severe weather for Southwest Louisiana began in early April, with an EF-2 tornado with maximum winds of 155 MPH and a max width of 250 yards touching ground in Lake Charles. With an ongoing trend of warm, summer storms and a predicted active hurricane season, this trend could continue.

There have been 13 confirmed tornadoes in Southwest Louisiana, Central Louisiana and Southeast Texas this year, Cramer said. Four were EF-2s and the rest were EF-1s. He could not confirm if this is an exceptional amount of tornadoes for this time of year.

What is a tornado?

NWS defines a tornado as a “narrow, violently rotating column of air that extends from a thunderstorm to the ground” and a phenomenon that “can be among the most violent of all atmospheric storms we experience.”

Especially destructive tornadoes occur during supercells, rotating thunderstorms that often result in hail, extreme winds, lightning and flash floods.

NWS Lake Charles Storm Warning Coordinator Doug Cramer said four ingredients are needed to make a tornado: moisture, instability (warm air in the lower parts of the atmosphere that can rise), a source of lift and wind shear different wind speeds and directions exhibiting height co-occurring).

What to do

Tornadoes are uniquely dangerous because of their unpredictability and powerful winds are concentrated in a smaller area.

Cramer said that one of the best ways to protect yourself in the case of a tornado is to have multiple methods of receiving warnings. Citizens should ensure they have access to their phones to receive NWS alerts in real-time, but it is recommended that they also use additional radar apps and keep an eye out for media alerts.

He said that the NWS has “done a pretty good job” alerting locals this year, as all 13 of the tornadoes in the area had warnings associated with them. During storms, weather watchers have to monitor the environment, radar and incoming spotter reports to determine if the weather is conducive for a tornado, or if one is already occurring.

Based on those observations, the NWS releases tornado watches or warnings.

A tornado watch is sent out when conditions are favorable for a tornado to form. A warning is given when NWS sees something on the radar that could indicate a tornado or if they have received a spotter reporter that “gives a clue” that a tornado is forming.

“We’re improving. … It’s our goal at the weather service to get the warning out before it happens,” he said.

Many homes, facilities and cities in the original tornado alley are equipped with basements and shelters to protect people from tornadoes. These are not resources that are generally available in Louisiana.

Cramer said it is critically important for people to designate an appropriate room for shelter during tornado events.  In the case of a tornado in the area, it is recommended that people shelter in the lowest level of the building they are in. People should seek out a small, central room without windows. This is the best protection.

“You want as many walls between you and the outside of the house as possible. That’s typically going to be the most secure area of your home.”

One of the potentially dangerous aspects of a tornado is flying debris. A tornado can be up to a mile wide, but the winds outside of the tornado can still pose a threat, flinging debris outside of the tornado’s area of impact.

If a person finds themselves outside, they should seek shelter in a building as soon as possible. If there are no buildings, seek shelter in a concrete culvert if it is not flooded.

“Try to position yourself underground in an area that protects you from flying debris,” he said.