The United States averages more than 1,150 tornadoes a year -- more than any other country.
In fact, it is higher than that of Canada, Australia and all European countries combined.
In the United States, every state has experienced at least one tornado, and some have dozens each year.
The country is special in terms of producing so many tornadoes, especially violent ones.
In fact, the average tornado fatality in the US is 73. But in Europe, where tornadoes are typically much weaker, fatalities are estimated to be between 10 and 15 per year.
Some states are deadlier than others
An average of 140 tornadoes per year occur in Texas, the highest number among all states.
Kansas, Florida, Oklahoma and Nebraska round out the top five.
But the total number of tornadoes doesn't always tell the whole story.
For example, although Alabama has an average of 42 tornadoes a year, more than three times fewer than Texas, it tops the list of tornado fatalities.
Alabama has an average of 14 tornado fatalities a year, almost twice as many as Missouri, the next state, with eight deaths a year.
The time of day and topography where the tornado occurs make a big difference in the fatality rate.
The topography of Alabama and other southern states often includes rolling hills, mesas, and many more trees than plains states like Kansas, Texas, and Nebraska, where a tornado can often be seen for miles.
A higher chance of tornado visibility often makes reporting faster and gives people time to seek shelter.
Southern states such as Tennessee, Kentucky, and Arkansas also record more tornadoes overnight than any other state.
This can lead to a higher number of fatalities, since many people are sleeping and are unaware that a tornado is approaching.
There is a threat of significant tornadoes, damaging winds, and hail for the southern US.
"Tornadoes in the Southeast tend to be more dangerous than those in the Great Plains," says Brandon Miller, a CNN meteorologist.
"There are several reasons for this, some meteorological and some geographic. Southeastern tornadoes tend to travel faster, driven by a faster jet stream."
All of these factors can lead to a higher death rate in the southern states compared to the plains.
But all of these states have a few things in common: the ideal weather conditions for tornadoes.
"The basic ingredients for severe thunderstorms that can produce tornadoes are warm, moist air near the ground, relatively dry, cool air at altitude (between 10,000 and 30,000 feet), and horizontal winds in the tornado-forming environment. storm that increase as you go from the ground up and change direction with height, blowing from the equator near the ground and from the west high up," says Dr. Harold Brooks, principal scientist at the National Laboratory for Severe Storms from the National Office of Oceanic and Atmospheric Administration (NOAA).
Low pressure systems in the US bring in warm, moist air from the Gulf of Mexico and cool, dry air from the Rocky Mountains or the High Desert in the Southwest.
The states that fall between those two regions end up being in the ideal place for severe weather conditions to be triggered.
"No other place in the world has such large warm waters on its equatorial side with a broad, high, north-south ridge to the west of it," Dr. Brooks said.
"All other tornado-prone regions have at least one suboptimal feature."
The graph explains the union between air masses at different temperatures.
The US leads all other countries in terms of tornadoes
Other countries experience tornadoes, such as Germany, Australia, South Africa, eastern China, Japan, Bangladesh, and Argentina, among others.
Europe as a whole is comparable to the size of the US, but there is a big difference in the number of tornadoes and tornado fatalities.
Between 2011 and 2020, the US had a preliminary average of 1,173 tornadoes per year, and Europe around 256. However, Dr. Pieter Groenemeijer, director of the European Severe Storms Laboratory (ESSL) , warns that the European figure may be down.
"It is likely that in some countries, such as France and the UK, weaker tornadoes will still go unreported," says Groenemeijer.
European Russia (which is the part of the country west of 58 degrees east longitude) tops the list with 86 annual tornadoes.
Germany ranks second, with an average of 28 tornadoes per year.
The maximum density of tornado reports coincides with the high population density over Belgium, the Netherlands and northern Germany, according to a study on severe storms in Europe published in December 2020.
The study also reports that storms are twice as frequent over the United States, with up to four times as many storm reports, compared to Europe.
One thing that most countries have in common is the time of day that tornadoes occur, which is most frequently during the afternoon and early evening.
But the high season is not the same.
In the US, spring is the peak of tornado activity.
In central and northern Europe, the main tornado season is summer, while in the western and central Mediterranean region it is autumn, and in the eastern Mediterranean winter.
Outside the United States, Canada ranks second on the list of countries with the most tornadoes, with an average of 100 per year.
Tornadoes are not limited to the Northern Hemisphere.
In Australia dozens of them are produced each year, and in South Africa they are also recorded annually.
South America, like other continents, has its own tornado hot spot, known as "tornado corridor."
This tornado corridor includes Argentina, Uruguay, Paraguay and a part of Brazil.
According to the New Zealand National Institute for Atmospheric and Water Research, tornadoes are relatively rare there.
On average, New Zealand experiences between seven and ten moderate to strong tornadoes each year.
Southern hemisphere tornadoes tend to spin clockwise, unlike tornadoes in the northern hemisphere.