Tornadoes usually form in the spring when thunderstorms create strong vertical wind shears that cause updrafts of wind to rotate at high speeds.
This violently rotating column of wind extends from the base of the thunderstorm cloud to the ground.
On the ground, the tornado’s swirling winds gather up dust and debris, which is why we can see them.
Tornadoes can grow to be 6,500 feet (1,981 m) high and 2,000 feet (610 m) across.
Wind speeds inside a tornado can reach 370 miles (596 km) per hour.
Although tornadoes can occur at any time, the season of greatest activity begins in the Gulf Coast states in early March.
The peak period in the southern Plains is from May to early June.
In the northern Plains and upper Midwest, most tornadoes occur in June and July.