Hurricane Karl was the eleventh named storm and the seventh hurricane of the 1998 Atlantic hurricane season. Karl formed from an extratropical low that moved eastward and was north of Bermuda on September 23. Karl moved east-southeast after forming, then eventually to the northeast, becoming a Category 2 hurricane with 105 mph winds. Karl passed the Azores, weakening to a tropical storm as it did so. On September 28, Karl became an extratropical cyclone.
Karl caused no damage and no reported fatalities.
|Formation||September 23, 1998|
|Dissipation||September 28, 1998|
|Highest winds||105 mph|
|Lowest pressure||970 mbar|
A small non-tropical low that was tracked from the Carolinas beginning on September 21. Deep convection became more organized as the low moved eastward into the open waters of the Atlantic Ocean. The low became organized enough to be classified as Tropical Depression Eleven on September 23 while located 50 miles west-northwest of the island of Bermuda. As banding features developed, the system became Tropical Storm Karl on the evening of September 23. At this time, Karl began moving east-southeast. Satellite imagery indicated that Karl was gradually developing a more symmetrical cloud pattern, with the center becoming embedded within the coldest convective cloudtops. Karl intensified into a hurricane near 1200 UTC on September 25, while centered about 550 miles east-southeast of Bermuda. At this time, Hurricane Georges was over the Florida Straits, Hurricane Ivan was over the North Atlantic located about 500 miles west-southwest of the Azores, and finally, Hurricane Jeanne was midway between Africa and the Lesser Antilles islands.
This made Karl the fourth hurricane to be simultaneously active in the tropical Atlantic during the 1998 season. According to records at the National Hurricane Center, the last time such an event occured was during the 1893 Atlantic hurricane season. Records also show that on September 11, 1961, three hurricanes simultaneously existed, and possibly a fourth hurricane existed. Karl began to move to the northeast after becoming a hurricane, in response to a large mid to upper level trough located west of the hurricane. A well-defined eye developed within Karl's center of circulation, and it is estimated that Karl reached its peak of 105 mph winds as a Category 2 hurricane at 0000 UTC on September 27, while located about 875 miles east-northeast of Bermuda. Karl's eye remained distinct for at least six hours, after which Karl began to weaken, primarily because of upper-level wind shear.
Karl continued accelerating northeast, and it weakened to a tropical storm at 0000 UTC on September 28, while located about 175 miles west-northwest of the westernmost portion of the Azores. Karl began to move over increasingly cooler waters, and became an extratropical cyclone late on September 28, as its center of circulation became well-removed from any deep convection. The extratropical cyclone was tracked to the south of Ireland on September 29.
Lack of Retirement
Because there was no damage, the name Karl was not retired in the Spring of 1999 by the World Meteorological Organization. It was used again in 2004, and is on the list of names to be used for the 2010 Atlantic hurricane season.