Hurricane Kyle (2002) - Meteorological History

Meteorological History

A cold front stalled and began weakening to the southeast of Bermuda on September 15, degenerating into a low pressure area by September 18. A stationary circulation developed by September 19, which was believed to have been aided by a trough to its west. Convection developed into narrow banding features far from the center, and the overall structure gradually organized. It is estimated the system developed into Subtropical Depression Twelve late on September 20, about 825 miles (1330 km) southeast of Bermuda; it was classified subtropical because of the distance of the convection from the center. The cyclone tracked northward within the weak steering flow between an upper-level low to its south and a trough to its north. Strengthening gradually, the depression attained subtropical storm status early on September 21, and as such was named Kyle by the National Hurricane Center.

After being named, Subtropical Storm Kyle tracked north-northeastward, gradually executing a clockwise loop. Initially, the circulation center remained partly exposed to the south and west of the deep convection. On September 22, convection increased around the center as the system developed a warm thermal core, and as such it was re-classified as a tropical cyclone. A building anticyclone to its northwest turned Kyle to the southwest. After briefly weakening, previously moderate wind shear began decreasing, which allowed convection to deepen and for outflow to further develop. Tracking over progressively warmer waters, Kyle began developing a banding eye feature late on September 24. Slow strengthening continued, and the storm attained hurricane status at 1200 UTC on September 25. The next day, Kyle reached peak winds of 85 mph (130 km/h) about 490 miles (790 km/h) east-southeast of Bermuda.

After maintaining peak intensity for about 24 hours, Kyle began weakening on September 27 as increased upper-level shear restricted outflow and distorted the convection envelop; drier air also contributed to the weakening. On September 28, after turning west-northwestward, the hurricane weakened to tropical storm status, and by the next day the center had become exposed from the deep convection. A trough passing to its north and a developing ridge to its west left the storm nearly stationary for several days. The weakening rate of Kyle was temporarily halted when thunderstorms re-developed on September 29 and again early the next day, though late on September 30 the storm weakened to tropical depression status. The circulation had become elongated from northeast to southwest. The northeast portion became associated with the approaching frontal zone, and was briefly monitored for signs of development. However, the southwestern portion re-developed convection and became the dominant circulation.

Remaining a tropical depression for about 18 hours, Kyle re-intensified to tropical storm status on October 1, after redeveloping some thunderstorms southeast of the center. Despite unfavorable wind shear, the convection became better organized, developing into rain bands and wrapping into the mid-level circulation of the storm. Late on October 2, Kyle developed an eye feature in the center of the storm, and the winds increased to about 65 mph (105 km/h); operationally it was forecast to regain hurricane status. However, the storm encountered further wind shear, which left the center exposed from the convection by early on October 4. Convection became intermittent and separated from the circulation, and Kyle again weakened to tropical depression status on October 5. By then, the storm had begun a steady west-northwest motion, which was followed by a slow turn to the north-northeast. On October 6, a decrease in wind shear allowed the cyclone to again reach tropical storm status, about 295 miles (475 km) west-northwest of Bermuda. Around the same time, the system was located in an area of weak steering currents; a ridge was to its northeast and southwest, an upper-level low was to its east-southeast, and a broad trough was to its northwest. By October 7, it began a slow southwestward motion around a ridge to its west. The circulation became elongated as dry air limited convection, and after shear increased on October 8, Kyle weakened to tropical depression status.

By early on October 9, the depression consisted of a circulation center without any of the associated deep convection that is one of the prerequisites of being a tropical cyclone. Several hurricane forecast models predicted Kyle to weaken until dissipation. After 24 hours without significant convection, thunderstorms reformed to the southeast of the center on October 10 as the depression entered an area of warmer water temperatures. Environmental conditions became more favorable, with weakening wind shear and decreasing dry air. The depression continued tracking around a ridge, turning to the west and west-northwest toward the coast of Florida. Convection increased markedly early on October 11 as it turned northward ahead of an approaching cold front, and Kyle regained tropical storm status about 35 miles (60 km) east of the border between Florida and Georgia.

After re-attaining tropical storm status, Kyle turned more to the northeast and parallel to the coastline, making landfall near McClellanville, South Carolina as a minimal tropical storm. The storm briefly moved over open waters before again making landfall near Long Beach, North Carolina late on October 11. By early on October 12, the storm had weakened to tropical depression status. At the time of it moving ashore, there was a separate non-tropical low to the northeast of the depression, and shear had greatly increased, which made re-intensification unlikely. However, convection redeveloped baroclinically with the approaching cold front, and Kyle attained tropical storm status for the fifth time over the eastern Pamlico Sound. The restrengthening was short-lived, as the wind field expanded while the convection transitioned into that of a frontal band. After emerging into the western Atlantic Ocean, Tropical Storm Kyle merged with a cold front late on October 12. The remnants of Kyle continued eastward, executing a loop on October 14 before turning northeastward and impacting the Azores on October 17. The next day, the remnants of Kyle were absorbed by an extratropical cyclone to its northwest, which continued northeastward and moved near the British Isles on October 23.