A hurricane radar band of circular or spiral shape associated with a tropical cyclone (hurricane or typhoon). Made evident by radar observations, hurricane bands typically curve cyclonically inward toward the center of the storm. The bands may be classified as primary if they merge into the eyewall encircling the eye of the storm, or secondary if they are disconnected from the eyewall. Hurricane bands generally move slowly around the center of the storm in the direction of the hurricane circulation. See banded structure.