Definitions for "Subtropical cyclone"
A non-frontal, yet non-tropical cyclone which forms over the subtropical waters.
A non-frontal low pressure system that has characteristics of both tropical and extratropical cyclones. The most common type is an upper-level cold low with circulation extending to the surface layer and maximum sustained winds generally occurring at a radius of about 100 miles or more from the center. In comparison to tropical cyclones, such systems have a relatively broad zone of maximum winds that is located farther from the center, and typically have a less symmetric wind field and distribution of convection. A second type of subtropical cyclone is a mesoscale low originating in or near a frontalyzing zone of horizontal wind shear, with radius of maximum sustained winds generally less than 30 miles. The entire circulation may initially have a diameter of less than 100 miles. These generally short-lived systems may be either cold core or warm core.
A non-frontal low pressure system that has characteristics of both tropical and extratropical cyclones. Subtropical cyclones, which can evolve into tropical cyclones, are generally of two types: (1) An upper level cold low with circulation extending to the surface and maximum sustained winds generally occurring at a radius of about 100 miles or more from the pressure center.(2) A mesoscale cyclone originating in or near a frontolyzing zone of horizontal wind shear, with radius of maximum sustained winds generally less than 30 miles. The entire circulation sometimes encompasses an area initially no more than 100 miles in diameter. These generally short-lived, marine cyclones may vary in structure from cold to warm core.