Massive walls of dust and debris called haboobs that roll through the U.S. Southwest can be awe-inspiring and terrifying, especially for motorists caught in their path.

A haboob is a type of dust storm that forms after a thunderstorm. They are usually quite large and can be thousands of feet high and up to 100 miles wide. During thunderstorms, cold air rushes down to the ground and spreads out. When this happens in an arid or semiarid region, the wind can kick up dust, forming a haboob.