On December 10, 2021, a powerful storm crossed the border, triggering at least 30 tornadoes that swept through six states in the central United States: Illinois, Kentucky, Tennessee, Missouri, Arkansas, and Mississippi, causing power outages and casualties in these six states. The roof of one of the Amazon warehouses in Edwardsville, Illinois, was overturned and the warehouse was badly damaged.
Every year we see the United States hit by tornadoes in the news. No country around the world has suffered tornadoes as often as the United States. According to statistics, there are an average of 5 tornadoes per day in the United States, and there are about 1,000 to 2,000 tornadoes per year. Because tornadoes in the United States are not only numerous, but also intense, the United States is known as the "home of tornadoes." According to statistics, 75% of the world's tornadoes occur in the United States.
On April 3, 1974, there was even a super-outbreak of tornadoes in the central United States, and in just 19 hours, 148 tornadoes appeared in 11 states, which was even more violent than this time.
In 2011, when tornadoes broke out in the southern United States, the World Meteorological Organization recorded 207 different tornadoes in a 24-hour period from April 27 to 28.
Tornadoes are upright, empty tubular swirling streams of air, a severe weather phenomenon that occurs at the local scale and occurs throughout the year, commonly in tropical and temperate regions, with the interior of the Americas and western Australia being the most common. The tornado has a wind speed of more than 100 meters per second, which is why its destructive power is amazing. A single tornado lasts only a few hours at most and ranges from 0 to 25 km.
Why are there so many tornadoes in the United States?
Tornado formation is associated with violent updrafts caused by unstable energy and vertical wind shear. The updraft creates a vertical vortex under the action of wind speed and wind direction shear, and begins to rotate horizontally. The United States has many thunderstorms, with an average of 100,000 thunderstorms per year, and this meteorological condition is just enough to meet the formation of tornadoes.
The United States, like China, is located in the northern hemisphere, except that the United States is in the western hemisphere, and the United States is bordered by the Atlantic Ocean in the east, the Pacific Ocean in the west, and the Gulf of Mexico in the south, which causes a large amount of water vapor to flow from the east, west and south to the Continental United States. With so much water vapor being sent to the continental United States, it's easy to create violent thunderstorms that trigger tornadoes. In addition, the United States also encounters tropical cyclones such as hurricanes every year.
China in the eastern hemisphere, only the east and south of the sea, because the geographical location is different from the United States, so rarely encounter tornadoes, but the southeast coastal areas will encounter typhoons every year.
In the United States, most tornadoes occur every spring, followed by summer. Because during this time period, thunderstorms in the United States are the most frequent.
The south-central United States is a high incidence of tornadoes, of which the south-central plains are called the "tornado corridor", this area is often controlled by subtropical high pressures in the spring and summer of each year, causing the air flow in the region to rise, and the warm and humid air flow from the Gulf of Mexico is constantly replenished, thus forming a large number of thunderstorms in the region, plus the plains, so it is more likely to produce tornadoes.
In short, the multi-tornadoes in the United States are mainly related to the geographical location, climatic conditions and atmospheric circulation characteristics of the United States.
Sometimes there are no tornado clouds, but also "tornadoes", this special tornado is called a "cloudless tornado", what is going on?
After the study, scientists believe that the reason for this phenomenon should be related to the large number of cars on the us roads. Traffic in the United States is to drive on the right, when two vehicles are driving opposite each other, it will form a counterclockwise rotation of air whirlpools, these large numbers of whirlpools once encountered favorable weather system and atmospheric temperature conditions, can also induce tornadoes.
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