One type of storm that is seen more during the spring season than at any other time of the year is a tornado. A tornado is classified as such when the vortex connects between the clouds of the storm and the ground below. Some storms have rotation in them, but until the rotation touches the ground, it’s not considered a tornado. Because of the terrain in North America, the continent sees more tornadoes than other continents in the world. There has been at least one tornado in each state. Radar images can often give information about storms and their severity, but there is no clear indication as to whether storms will produce a tornado or not. Most tornadoes last for about 10 minutes. Large wedge tornadoes can travel for miles and can stay on the ground for much longer than 10 minutes, especially if they travel across an open area with nothing in their way to break up the rotation of the vortex. These tornadoes are often seen in the plain states, such as Nebraska and Kansas. This area of the United States is also known as Tornado Alley because of the high number of tornadoes that are seen compared to other states.