A cyclone is a system of wind that moves rapidly inward with a low-pressure area in the middle. In meteorology, it refers to the large mass of air that surrounds a strong atmospheric center. The internal winds moving over an area of low pressure allow us to view the storm in a spiral shape. The large-scale (synoptic scale) polar vortex and extra-tropical cyclones are the largest low-pressure systems. The synchronous scale also includes tropical cyclones such as tropical cyclones and subtropical cyclones.