Hurricane Floyd - Meteorological History

Meteorological History

Floyd originated as a tropical wave that exited the coast of Africa on September 2. It moved steadily westward and remained disorganized and devoid of deep convection until September 7, when a curved band of deep convection developed over the center in response to a developing anticyclone. At this point, the National Hurricane Center designated it as Tropical Depression Eight, while it was approximately 1,000 mi (1,600 km) east of the Lesser Antilles. A strong ridge of high pressure to its north forced the developing tropical cyclone westward over warmer waters, allowing it to strengthen to Tropical Storm Floyd on September 8.

Although a large storm, Floyd initially lacked a well-defined inner core, resulting in slow strengthening and preventing rapid intensification. On September 10 it organized enough to reach hurricane status, and Floyd approached major hurricane strength on September 11 while north of the Leeward Islands. The central Atlantic upper tropospheric trough, along with an upper-level low in the eastern Caribbean Sea, produced vertical wind shear over the hurricane and caused its winds to weaken to 85 mph (137 km/h). A turn to the west, caused by building of high pressures, was followed by a period of rapid intensification: in 24 hours maximum sustained winds increased from 110 mph (180 km/h) to 155 mph (249 km/h), while the pressure dropped to 921 mb (921 hPa; 27.2 inHg) by morning on September 13, the third lowest pressure for a hurricane not to reach Category 5 intensity in the Atlantic Ocean—only Hurricane Opal and Hurricane Gloria had lower pressures than Floyd. One contributor to the intensification was the high oceanic heat content along the storm's path.

Hurricane Floyd remained just below Category 5 status on the Saffir–Simpson Hurricane Scale for 12 hours while crossing The Bahamas, making landfalls on Eleuthera and Abaco islands, before an eyewall replacement cycle weakened it to a Category 3 hurricane with winds of 120 mph (190 km/h). The new, larger eyewall contracted slightly, and the hurricane briefly re-intensified to Category 4 status. A strong mid- to upper-level trough eroded the western portion of the high-pressure ridge, steering Floyd to the northwest. It paralleled the eastern Florida coast 110 miles (180 km) off shore, and steadily weakened because of entrainment of dry air and upper-level shear. The storm remained extremely large, however; at its peak, tropical storm-force winds spanned a diameter of 580 mi (930 km), making Floyd one of the largest Atlantic hurricanes of its intensity ever recorded.

Floyd accelerated to the north and northeast, and weakened greatly to a Category 2 hurricane. It made landfall in Cape Fear, North Carolina with winds of 105 mph (169 km/h) on September 16. After crossing over North Carolina and southeastern Virginia, it briefly re-entered the western Atlantic Ocean before reaching Long Island on September 17. The storm gradually lost its tropical characteristics due to an approaching frontal zone and became extratropical over southern Maine late on September 17. The extratropical storm continued to the northeast, and after passing over the Canadian Maritimes, it was absorbed by a cold front to the east of Newfoundland.