Why Does The US Suffer From Deadly Tornadoes Like In Kentucky

Why does the US suffer from deadly tornadoes like in Kentucky?

The historic tornadoes in the US occurred mainly due to weather causes. However, scientists are working to better understand the link between climate change and tornadoes.

In the United States, tornadoes are rare in December, but that's not impossible, with the tornadoes over the weekend being a prime example. Dozens of tornadoes swept across the Midwest and Southern states of the United States, of which Kentucky was the worst-affected state, causing the death toll to even reach 100.

"It was surprising and unbelievable," Professor Victor Gensini, a meteorologist at Northern Illinois University, told the AP.

Weather factors, including temperature, air humidity or La Nina phenomenon, are the direct cause of this historic tornado. Meanwhile, scientists are studying whether climate change will make tornadoes more dangerous.

How are tornadoes created?

 

Tornadoes are tall columns of gas that swirl vertically from the air to the ground. Formed from thunderstorms, they have a high speed of movement and destroy all obstacles in their path.

 

Cyclones are created when heavier, drier, and cooler air masses above, pressurize warmer and wetter air masses below when the atmosphere is in an unstable state. At that time, the warm air mass below will move up. Due to the action of the wind, the air mass will begin to rotate.

 

As the wind strength and direction change, the mass of air will have enough rotational force to become a tornado. "That's what just happened over the weekend," said meteorology professor Paul Markowski at Pennsylvania State University.

 

Differences in wind direction and speed over high altitudes are noticeable in winter, due to differences in temperature and air pressure.

 

However, the winter air is usually more stable. Therefore, tornadoes often occur in the spring, when the air is warm and humid.

 

The United States is the country most affected by tornadoes in the world. On average, there are about 1,200 tornadoes each year, according to the National Oceanic and Atmospheric Administration (NOAA).

 

Why was the last tornado so terrible?

 

In December of this year, the weather in the Midwest and South America is quite similar to spring. Air temperature and humidity remain high. Warm, humid air makes the atmosphere unstable, creating conditions for powerful tornadoes to form.

 

The La Nina phenomenon is also partly responsible for this. However, scientists warn that warm winters will become more frequent as the Earth warms.

 

“The worst-case scenario happened. It's warm air during the cold season, and in the middle of the night," said John Gordon, a meteorologist with the Weather Service in Louisville, Kentucky.

 

Usually, tornadoes will gradually disappear as the storm above weakens. This process usually takes a few minutes. However, when the wind conditions at different altitudes are large, the cyclone is energized and continues to exist.

 

The tornadoes on the night of December 10 lasted for hours. A tornado was traveling at a speed of about 322 km, nearly breaking the 352 km record recorded in 1925.

 

“For such great lengths, the vortex must travel at a very high speed. The speed of the cyclone has exceeded 80 km / h for most of its existence," Professor Gensini said. "This is the 'high-speed' motion of a hurricane."

 

How does climate change affect tornadoes?

 

The relationship between climate change and tornadoes in the US is still the subject of research by scientists. This is not an easy thing, when the consequences of climate change often create opposite effects. In addition, only about 10% of large thunderstorms cause tornadoes, making comparisons more difficult.

 

However, American scientists found that thunderstorms are changing as the Earth warms. According to Professor Gensini, the frequency of large thunderstorms is increasing day by day. Winter air tends to be warmer, making this type of weather more likely to occur.

 

Sharing the same opinion, Harold Brooks, a scientist specializing in tornado studies at the US National Hurricane Institute, said that the US may have to see more tornadoes in the winter when temperatures tend to increase. On the contrary, he believes that the frequency of storms in the summer will decrease.

 

According to professor Jason Furtado at the University of Oklahoma, the location of most frequent tornadoes has also shifted eastward, to the Mississippi River valley area. This phenomenon is caused by changes in temperature, humidity and wind conditions.

 

"Residents in the Mississippi River Valley and the Ohio River Valley will face more hurricanes in the future," he said.