Why do 90 percent of all tornadoes occur in the united states?

Answer 1

There are two reasons.

First, the central United States has an ideal Climate setup for tornadoes in the spring and early summer. Warm, moist air comes in from the Gulf of Mexico and cool air from Canada and/or dry air from the Rockies . This triggers thunderstorms. Initially either development is held back by a layer of stable air called a cap, which allows instability to build until the storms can break through it. When they do, the added instability makes them stronger. Finally, strong upper level winds create wind shear, which sets thunderstorms rotating, allowing them to produce tornadoes. Similar conditions can occur elsewhere, but not as often.

A second important factor is that the United States only gets a large majority of recorded tornadoes, not all tornadoes. The National Weather Service puts effort into documenting as many tornadoes as possible, even the weakest of them. Most other countries do not conducts extensive damage surveys, so most tornadoes that occur are never recorded unless they cause major damage.

Answer 2

Tornadoes are most common in the United States due to its unique geographical and atmospheric conditions. The collision of warm, moist air from the Gulf of Mexico with cool, dry air from Canada creates the perfect environment for tornado formation, especially in the central region known as Tornado Alley. Additionally, the country's size and location allow for a wide range of weather patterns to interact, increasing the likelihood of severe storms and tornadoes.