Tornadoes increasing in Arkansas due to climate change, researcher says – Arkansas Times
On the afternoon of Saturday, March 28, 2020, Kathie Pace and her family hid in a stairwell as a tornado slashed through their northeast Jonesboro subdivision.
“I heard the windows shattering,” she said recently. “Later, we found someone’s turbine from their roof in our living room. We were picking up pieces of glass for months.”
“It only lasted three to five minutes,” Pace said. “But when we went outside … wow.” The tornado, rated an EF3 on a zero-to-five scale measuring intensity, cut a path through the heart of Jonesboro, injuring at least 22. It destroyed homes and businesses across the city and severely damaged the Turtle Creek Mall. (There were no fatalities, perhaps in part because many people were at home due to COVID-19 restrictions.)
Pace said she was lucky. Her house only received about $30,000 worth of damage, including the cost of a new roof. Other homeowners had to rebuild from the slab up. Fifteen months later, the homes in her subdivision are all rebuilt, she said, but at least three neighbors have added storm shelters.
Some research suggests such an addition may be a wise investment in Arkansas. Tornadoes appear to be on the increase in the mid-South in recent years, thanks to climate change and shifting weather patterns across the continent.
The classic “Tornado Alley” region of the U.S. is the southern Great Plains. Powerful storms ravage north Texas, Oklahoma and Kansas as cold air from the Rocky Mountains collides with the heat of the Plains.
But some scientists have noticed a recent eastern shift in that pattern, possibly placing parts of Arkansas in the bull’s eye of more destructive storms, along with Alabama, Mississippi and western Tennessee. While tornadoes are still abundant on the Plains, meteorologists have recorded an increase in the number and intensity of twisters in an area some refer to as “Dixie Alley.”
Victor Gensini, a professor of meteorology at Northern Illinois University, authored a paper about the shift in 2018. Since then, he said, the trend is continuing. He credits increased drought conditions in the western U.S., which push the “dry line,” a boundary that separates moist and dry air masses and is a factor in creating severe weather.
“The southern Great Plains are drying out,” Gensini said. “Elevated air is moving the dry line. The drought is pushing everything to the east.”
The U.S Drought Monitor, a weekly report compiled by the National Drought Mitigation Center at the University of Nebraska at Lincoln, predicts the West may see the second worst drought this year in 1,200 years. Some areas of California may see irreparable damage following winter temperatures of 5 to 15 degrees above normal and a lack of snowfall.
The dry atmospheric conditions create a dome of high pressure over the western U.S., causing the weather systems that can produce tornadoes to begin forming further east. Meanwhile, drought in the Dakotas is contributing to the jet stream dipping further south. The jet stream, an atmospheric current of frigid Arctic air, is another ingredient in forming tornado-producing supercell storms.
Many tornadoes still blast through Tornado Alley, but Gensini’s research says there has been a significant decrease in both reports of tornadoes and tornadic atmospheric conditions in portions of Texas, Oklahoma and other Plains states. The inverse is true in the Southeast, he said.
“Tornadoes are tied to underlying moisture,” Gensini said, which the Gulf of Mexico provides in abundance. “You have the drought pushing the jet stream further into the Gulf states. More moisture means [inclement weather] activity lights up. It’s creating a new trough for these storms to line up.”
Gensini blames manmade climate change for the shift. “We are clearly warming, and it’s what’s causing the movement of tornadoes,” he said.
To be clear, the South has always had its share of tornadoes. Arkansas’s only documented EF5 tornado — the highest on the intensity scale — formed south of Batesville nearly a century ago. Known as the “Sneed Tornado,” it ripped through Independence, Jackson and Lawrence counties on April 10, 1929, killing 23. (Some meteorologists believe the EF4 tornado that hit Vilonia and Mayflower on April 27, 2014, may have also increased to an EF5 at times during its 41-mile long trek.)
But Gensini says there’s been a “significant increase” in tornadic activity in Arkansas, Alabama, Tennessee and Mississippi in recent decades. Such a measurement is not as straightforward as simply counting the number of recorded tornadoes, which vary in terms of intensity, duration and other metrics, complicating year-to-year comparisons.
Gensini tracked the number of tornado reports from 1979 to 2010 for his study but also used an index called the Significant Tornado Parameter, which monitors the atmospheric ingredients favorable for the formation of tornadoes. (The Weather Channel created a similar measurement called the Tornado Condition Index, or TORCON, which attempts to measure the chance of a tornado forming within a 50-mile radius of a given location.)
Gensini acknowledged his research is somewhat hindered by limited data. Detailed, accurate tornado statistics that include location, strength and path only go back to the 1950s.
“Arkansas and other states have long tornado histories,” he said. “We are only seeing a portion of that.”
Justin Condry, an National Weather Service meteorologist in North Little Rock, said he’s also noticed an increase in powerful storms in the South.
“It seems we’ve been issuing more warnings than before,” he said.
The state has averaged 33 twisters a year for the past 70 years, Condry said. However, that number increases to an average of 45 per year when tallying the last 10 years alone.
Last year, Arkansas recorded 45 tornadoes. There were 41 in 2019 and 36 in 2018. This year, as of June 4, the state has seen 16.
Condry said the National Weather Service, while not declaring climate change is the cause, does agree with Gensini’s findings that a shift is occurring.
“To some extent, I think it is global warming,” Condry said. “But it’s a controversial topic. We don’t have weather data that goes back hundreds of years to show that this is either manmade and new or if it is a cyclical, long-range weather pattern.
“There is no denying, though, that the ‘Dixie Alley’ area is looking more impressive,” he said.
Tornadoes in the South may be more dangerous, Gensini said, partly because they are harder to see. Trees and hills impede views of the landscape, unlike on the barren Plains. Also, tornadoes are more likely to form under cover of darkness: Because the area generally has higher temperatures during the day, the cooling shift — one of the required ingredients in producing twisters — often doesn’t occur until well into the night, when people are asleep.
The South is also more densely populated than the Great Plains. Add in that manufactured homes are more abundant, and it creates a recipe for disaster, Gensini said.
“Manufactured homes are a huge deal for casualties,” he said. “A vast majority of fatalities and injuries occur when mobile homes are hit by tornadoes. There is a succinct vulnerability in the Southeast to storms because of that.”
“They are forming in the most vulnerable area,” he said. “Arkansas is in the footprint of this change.”
In Jonesboro, there are still reminders of the wrath of the storm that produced the EF3 tornado last March. Debris lies scattered in a field along Old Bridger Road, and thin sheets of metal can be seen wrapped around tree branches.
“I think that tornado caught us off guard,” admitted Anthony Coy, the director of emergency services for Craighead County. “The criteria that day did not meet the requirements to pre-activate our emergency plans.”
Just before the Jonesboro tornado touched down, the National Weather Service’s Storm Prediction Center upgraded the area’s possibility of severe weather from “slight’ to “enhanced.” Since then, Coy said, the Craighead County Office of Emergency Management has activated its emergency operations center five times for storm warnings in the county.
“I don’t remember having this many warnings in such a short time,” he said. “I think as a result of that Jonesboro tornado, we learned we need to be more ready for any sudden changes.”
To Kathie Pace, the Jonesboro resident who weathered the storm in her stairwell, severe weather is nothing new. She was working at a jewelry store in the old Indian Mall on Caraway Road, she said, when a May 27, 1973, tornado flattened much of the southern half of Jonesboro, including portions of the mall.
“I should be more nervous when clouds come,” Pace said. “But I already felt that we lived in ‘tornado alley.’ Growing up, it seemed like every March or April, we’d get tornadoes.”
“If you live here in Arkansas long enough, you’ll probably see one,” she said.
This story is courtesy of the Arkansas Nonprofit News Network, an independent, nonpartisan news project dedicated to producing journalism that matters to Arkansans.