Hurricane Gert (1999)
Hurricane Gert was the fourth of five major hurricanes in the moderately active 1999 Atlantic hurricane season. A Cape Verde hurricane, Gert formed on September 11 off the coast of Africa before heading west-northwest. It reached a peak wind speed of 150 mph by September 15 over the open central Atlantic east-northeast of the Leeward Islands. It gradually curved to the northwest and later to the north, due to a weakness in the subtropical ridge created by Hurricane Floyd. Hurricane Gert passed east of Bermuda on September 21 and began a steady weakening trend at that time. It turned to the northeast, and on September 23, Gert transitioned into an extratropical cyclone to the southeast of Atlantic Canada before being absorbed by a larger storm.
For several days, Gert threatened to strike Bermuda, prompting the evacuation of tourists. Although Gert's center did not make landfall, it passed a short distance east of the island, producing hurricane-force winds that left 11,000 people without power. High waves swept two people out to sea at Acadia National Park in Maine. Later, strong waves struck Newfoundland and left heavy marine damage.
Meteorological history
A tropical wave moved off the coast of Africa on September 10, with evidence of a low-level circulation and convective banding. It moved west-northwestward, located south of a subtropical ridge. Around 12:00 UTC on September 11, Tropical Depression Nine formed to the south of the Cape Verde islands, although easterly wind shear halted initial development. The thunderstorms became better organized on September 12, and the National Hurricane Center upgraded it to Tropical Storm Gert. With an anticyclone aloft and warm water temperatures, Gert quickly intensified amid favorable conditions. Following the development of a warm spot near the center, Gert intensified into a hurricane on September 13. Early on September 15, Gert attained major hurricane strength, or a Category 3 on the Saffir-Simpson scale, as it developed well-defined outflow around a central dense overcast. Early on September 16, Gert reached peak winds of based on satellite-estimates, making it a Category 4 hurricane. At the time, the hurricane was located about 720 mi east-northeast of Guadeloupe in the Lesser Antilles.Hurricane Hunters investigated the hurricane on September 16 and indicated a slight weakening trend due to an eyewall replacement cycle. Gert turned toward the northwest due to a weakness in the subtropical ridge, created by Hurricane Floyd to the west. Gert weakened slightly due to increased wind shear, but restrengthened after the eyewall replacement cycle completed. The hurricane's structure degraded due to the intrusion of dry air, and Gert weakened again. On September 21, the hurricane passed about east of Bermuda as a Category 2 hurricane. The path turned toward the northeast due to an approaching trough. Cooler waters further weakened the hurricane, and on September 23 Gert weakened to tropical storm status as it approached Newfoundland. At 12:00 UTC that day, Gert transitioned into an extratropical cyclone about 55 mi southeast of Cape Race. About six hours later, the remnants of Gert were absorbed by a larger extratropical storm. Gert was the fourth of five Category 4 hurricanes to form during the 1999 season, the highest number of such storms on record. Later, the 2005 and 2020 seasons tied the record.