Hazards Resulting from Atmospheric Disturbances

Tornadoes are caused by the interaction of warm, moist air and cool, dry air.  In the USA this often occurs during the spring and summer months in areas of the United States known as Tornado Alley, which includes parts of Texas, Oklahoma, Kansas, Nebraska, and other states.

When these two air masses meet, they create instability in the atmosphere, which can lead to the formation of thunderstorms. Tornadoes often form within these thunderstorms when strong updrafts of warm air collide with downdrafts of cool air.

The spinning motion of a tornado is created by wind shear, which is the difference in wind speed and direction between the ground and the upper atmosphere. As the rotating column of air stretches upward, it becomes narrower and begins to spin faster, creating the characteristic funnel shape of a tornado.

While scientists understand the basic mechanisms behind tornado formation, predicting exactly when and where a tornado will form remains a challenge.

Case studies