Hurricane Isaac was the ninth named storm, the fifth hurricane, and the second major hurricane of the 2000 Atlantic hurricane season. Isaac formed as a Cape Verde hurricane, forming from a tropical wave that moved off the coast of Africa on September 20. The wave became a tropical depression on September 21 near the Cape Verde Islands, and quickly became Tropical Storm Isaac. Isaac reached a peak intensity of 140 mph and a pressure of 943 mb in the open Atlantic Ocean, well away from any land areas. Isaac dissipated on October 1.
Isaac caused no damage, but killed one person along the East Coast of the United States because of large swells.
|Formation||September 21, 2000|
|Dissipation||October 1, 2000|
|Highest winds||70 mph|
|Lowest pressure||943 mbar|
On September 20, a strong tropical wave emerged off the coast of Africa, with some curvature in association with the deep convection that accompanied the wave. The wave produced a very well-defined lower-tropospheric wind shift in the time section from Dakar, Senegal. Later on September 20, Dvorak classifications began on the wave. On September 21, as the wave continued westward, the cloud pattern became better-defined, and it developed into Tropical Depression Thirteen, while located a few hundred miles south of the Cape Verde Islands. After forming, the depression moved west-northwest, and quickly strengthened into Tropical Storm Isaac by 0000 UTC on September 22. Isaac continued moving west-northwest, courtesy of a ridge of high pressure to its north. Isaac continued to strengthen, and by 1200 UTC on September 23, Isaac became a hurricane, when a faint eye appeared on visible satellite imagery. Shortly after becoming a hurricane, the eye of Isaac became much better-defined on satellite imagery, and by 0000 UTC on September 24, Isaac's winds increased to 120 mph, making it a Category 3 hurricane on the Saffir-Simpson Hurricane Scale. Shortly thereafter, however, Isaac's cloud pattern became less organized, and the core of convection became less symmetric, and the eye was not as well-defined as it had been on September 23. This appeared to be caused mainly by internal fluctuations, as the large-scale environment ahead of Isaac remained favorable for intensification.
On September 25, Isaac weakened to a Category 2 hurricane, when it encountered west-southwesterly vertical wind shear. In addition, slightly cooler waters may have played a role in Isaac's weakening. By around 1200 UTC on September 26, the low-level cloud center of the hurricane was near the southwest edge of the main convection, and as a result, Isaac weakened further, to an 80 mph Category 1 hurricane. Later on September 26, the shear relaxed somewhat, and deep convection redeveloped over Isaac's center and became more symmetrical. On September 27, Isaac began to re-strengthen. A distinct eye again became visible on satellite imagery, and Isaac became a Category 3 hurricane again around 0000 UTC on September 28. At this time, Isaac took a turn to the northwest and continued to intensify, and reached its peak intensity of 140 mph around 1800 UTC on September 28. Shortly after peaking, Isaac moved north-northwest. Continuing its movement around the western periphery of a mid-tropospheric anticyclone, Isaac turned northward, and then north-northeast, and Isaac's center passed about 440 miles east of Bermuda on September 29. When Isaac moved over cooler waters on September 30, the winds greatly diminished, and Isaac weakened to a Category 1 hurricane. Isaac continued to accelerate to the northeast, and on October 1, Isaac weakened to a tropical storm. Later that day, Isaac became extratropical.
Isaac's extratropical remnants moved rapidly east-northeast across the cold waters of the north Atlanic Ocean, carrying winds of 65 to 70 mph. By October 3, Isaac's remnants moved northeastward and skirted the western British Isles, and Isaac's winds had decreased to 50 mph at this time. Early on October 4, Isaac's remnants merged with another larger extratropical low north of Scotland.
Isaac caused no damage, but managed to kill one person along the East Coast of the United States, namely Long Island, when large swells it generated capsized a boat with 4 passengers on it on September 30. One of them drowned. Also, it is estimated that near gale-force winds occured in the British Isles when Isaac's extratropical remnants struck the area.
Lack of Retirement
Because of the lack of damage, the name Isaac was not retired in the Spring of 2001 by the World Meteorological Organization. It was used again during the 2006 season, and is on the list of names to be used for the 2012 Atlantic hurricane season.