On Friday and Saturday, dozens of tornadoes – including one that ripped through more than 200 miles – struck Kentucky, Tennessee and Arkansas. They also killed at least 14 people in four other states, as well as dozens more in Kentucky.
Many people are wondering if the devastation in the region was related to climate change.
All of the recent extreme weather events — from wildfires in America to historic flooding in Western Europe — are clearly connected to record rainfall, high temperatures and other effects of warming planet.
However, the same cannot be said about tornadoes.
As states reel from the wrath of tornadoes, 74 people are killed and 109 remain unaccounted for in Kentucky
Scientists know that tornadoes are caused by warm weather and that climate change is changing the environment that these storms can form. However, they are unable to connect the dots because the research on the connection between climate and tornadoes is still behind other extreme weather events like hurricanes or wildfire.
This is at least partially due to a dearth of data, even though the U.S. is the leader in tornadoes with an average of 1,200 per year.
According to Harold Brooks, a scientist at The National Severe Storms Laboratory who studies tornadoes in severe thunderstorms, less than 10% of them produce tornadoes. This makes it difficult to draw solid conclusions about their causes and how climate change might influence them.
The quality of the observational data and the ability to use models to simulate certain weather phenomena are two other factors that can make it difficult for climate change attribution. According to the National Oceanic and Atmospheric Administration, this is true for tornadoes.
A page on the website states that “the observational record is inconsistent and relatively short”, and the models remain inconclusive regarding replicating tornado activity. Furthermore, our understanding of global warming and climate changes’ impact on the various atmospheric processes that produce tornadoes, such as wind shear, is less limited.
Scientists may not be able conclusively link tornado intensity or frequency to human-caused global warming, but they do believe there are some signs.
Here are their secrets:
What are tornadoes and when do they occur?
NOAA defines tornadoes to be narrow, rapidly rotating columns of air that extend between a thunderstorm and the ground. While the wind part of a tornado is not visible, it can form condensation funnels of water droplets or dust. They can cause destruction of homes and infrastructure, as well as sending debris flying.
Tornadoes are possible in any part the United States at any time.
Although they are traditionally associated with the Great Plains and the Great Plains, experts warn that the notion of “Tornado Alley,” as the term is commonly used, can be misleading. The tornado threat is quite a moving target. It moves from the Southeast during the cooler months to the central Plains in May, June and July, and then the northern Plains and Midwest in early summer.
People often refer to “tornado season” as the time of the year when the U.S. experiences the most tornadoes. It is usually May and June on the southern Plains, and then later in the northern Plains or upper Midwest. Experts say this isn’t a typical tornado season. However, the tornadoes that occurred on Saturday were quite unusual.
What conditions created this weekend’s storm?
Two contributing factors are being pointed out by meteorologists: strong winds and warm temperatures.
Thunderstorms are created when colder, denser air is pushed over warmer, humid air. According to the Associated Press, an updraft is formed when warm air rises. The wind direction and speed can change, which is known as “wind shear”, and cause the updraft spin. This creates the conditions for a tornado.
Winter is not prone to wind instability because it’s usually not as warm or humid. However, this was not the case on the weekend.
On Friday, temperatures were spring-like in the South and Midwest. Memphis, Tenn. saw a record-setting temperature of almost 80 degrees Fahrenheit.
“The atmosphere didn’t know it was December — temperatures between 70 and 80 degrees,” tweeted Craig Ceecee, a Mississippi-based meteorologist.
This could be due to many factors, including the La Nina climate pattern that brings warmer-than-average conditions in the Southern U.S., the Gulf of Mexico’s above-average water temperature, and the warming planet.
These high temperatures allowed for the formation of thunderstorms thanks to warm, moist atmosphere. Experts believe that a strong wind shear, which is common in winter, prolonged the tornadoes’ duration once they formed.
Victor Gensini from Northern Illinois University is a meteorology professor. He told AP that tornadoes usually lose energy in minutes. However, this weekend’s tornadoes lasted hours.
The U.S. will probably see more tornadoes than their usual time and place.
Experts believe climate change is affecting the conditions that tornadoes form. This could result in changes in the time and place where they are seen.
John T. Allen, a Professor of Meteorology at Central Michigan University, stated in an opinion column for USA Today that although the ties to climate changes are still unclear, there has been an “eastward shift” in tornado frequency and increased frequency of tornadoes during outbreaks over recent decades.
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He said that climate projections for the 21st century suggest that conditions conducive to tornadoes and severe storms will increase in North America. The impact could be most severe during the winter and autumn.
Brooks of NOAA’s National Severe Storms Laboratory said that the U.S. will likely see more tornadoes during winter than in summer, as long as the national average temperature rises.
Gensini also told Axios that forecasts indicate an increase in major outbreaks throughout the Southeast and mid-South. Axios also suggested that tornado-climate change could be attributed to the steroids era in baseball. Gensini said: “Pinning an individual homerun on steroid use can be difficult, but the overall trends are obvious.”
