The United States of America, commonly referred to as the United States or just America, is a federal republic which is composed of 50 states, a federal district, five major self-governing territories, and several islands. It is one of the largest countries in the world and is populated by over 325 million people.
The United States is the most tornado-prone country in the world, typically producing more than 1,000 tornadoes per year. Most of these tornadoes occur in Tornado Alley, although they can occur in any state at any time of the year.
Why does the United States get so many twisters?Edit
The United States receives so many tornadoes per year mostly because of the Rocky Mountains and the Gulf of Mexico. These two areas provide an unfortunate perfect breeding ground for tornadoes. The requirements for a tornado to be produced are:
- Warm, moist air at low levels
- Cool, dry air aloft
- Horizontal winds that increase with height from the ground-up—and change direction, so that they blow from the equator at low levels, and from the west aloft.
The US sees all three of these ingredients:
- Winds out of the South bring warm, moist air from the Gulf at low levels over the eastern half of the United States.
- Winds out of the West bring air over the Rocky Mountains and High Desert of the Southwest, making that air dry and cool aloft.
- Because of the Earth’s rotation, the winds are almost always aloft coming out of the West.
However, this feature is not unique to the United States. Areas in Northern South America, South Mexico, Northern Australia, Southern Asia and most of Africa also unfortunately fit those criterias.
Even if you don't live in these regions, it's important to note that tornadoes have occurred and been reported in every continent in the world.