What causes the formation of tornadoes?

Tornadoes form when warm, moist air collides with cold, dry air, creating instability in the atmosphere. The warm air rises rapidly, and if conditions are right, it may begin to spin due to wind shear (changes in wind speed and direction with height). As the rotating column of air intensifies, it can extend downward from the thunderstorm cloud, touching the ground and forming a tornado. Tornadoes are often accompanied by severe thunderstorms and are most common in areas like the Great Plains of the United States.