The United States is the country in which tornadoes occur the most frequently, with an average of 1,200 tornadoes registered each year, according to the Storm Prediction Center of the US National Office of Oceanic and Atmospheric Administration.
The primary reason for this is the geographical location of the country, as tornadoes tend to occur in the transition zone between polar and tropical air masses, which is the region where the contiguous US states are located. This region is characterized by the convergence of cold air flowing in from the north, warm waters from the Gulf of Mexico, and dry air from the Rocky Mountains, creating the perfect conditions for tornado formation.
A tornado is essentially a column of air that rotates violently and extends from the base of a cumulonimbus cloud. These clouds represent great vertical development that can reach heights of up to 50-60 thousand feet in the tropics. Tornadoes form in the most dangerous cumulonimbus clouds, known as supercells.
Tornadoes can vary in size, with a vertical length of around 6 thousand feet or 2 kilometers. The duration of a tornado can range from mere seconds up to over an hour, depending on the angular velocity and overall strength.
Tornado season and impacts
While tornados can technically form throughout the year, there is a greater occurrence during spring and summer in the United States. The impacts of these storms can be devastating, as recently demonstrated by tornadoes in Alabama and Mississippi that have caused death and destruction.
Experts identify that the regions of Mexico and Canada where tornadoes frequently occur are those situated adjacent to the US. This highlights the clear link between regional climate conditions and tornado formation, indicating that more research is needed to better understand these storms and their underlying causes.