A tropical cyclone having sustained surface winds between 39 and 73 mi (63 and 118 km) per hour. See Note at cyclone.
organized centre of low pressure that originates over warm tropical oceans. The maximum sustained surface winds of tropical storms range from 63 to 118 km (39 to 73 miles) per hour. These storms represent an intermediate stage between loosely organized tropical depressions and more intense tropical cyclones, which are also called hurricanes or typhoons in different parts of the globe. A tropical storm may occur in any of Earth's ocean basins in which tropical cyclones are found (North Atlantic, northeast Pacific, central Pacific, northwest and southwest Pacific, and Indian). The size and structure of tropical storms are similar to those of the more intense and mature tropical cyclones; they possess horizontal dimensions of about 160 km (100 miles) and winds that are highest at the surface but decrease with altitude. The winds typically attain their maximum intensity at approximately 30-50 km (20-30 miles) away from the centre of the circulation, but the distinct eyewall that is a characteristic of mature tropical cyclones is usually absent.
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