Hurricane Lisa was the twelfth named storm and the eighth hurricane of the 1998 Atlantic hurricane season. Lisa formed midway between Africa and the Lesser Antilles on October 5. It then headed northwest, then northeast, and then finally north, where it attained hurricane status in the open Atlantic Ocean far away from land. Lisa dissipated on October 9.
Lisa caused no damage and no reported fatalities.
|Formation||October 4, 1998|
|Dissipation||October 9, 1998|
|Highest winds||75 mph|
|Lowest pressure||995 mbar|
A tropical wave moved off the coast of Africa on September 29. The associated cloudiness was fairly well-organized, and was centered at 10°N latitude. The next day, it was an almost indistinguishable part of the Intertropical Convergence Zone (ITCZ), which was active across the entire tropical Atlantic at that time. By October 3, the wave became better organized, with its convection increasing, and it became seperated from the ITCZ. On October 4, when the wave was midway between Africa and the Lesser Antilles islands, signs of a low-level circulation became apparent. It is estimated that Tropical Depression Twelve developed from this wave at 0000 UTC on October 5. Later on October 5, the depression became Tropical Storm Lisa, the twelfth storm of the 1998 season. Lisa was embedded in an environment of strong vertical wind shear, with the low-level center being exposed to the west of the associated deep convection. The shear was created by an upper-level low to the northwest of Lisa.
This low also weakened the ridge to the north of the cyclone, and this caused Lisa to turn to the north. During the next two days, a strong baroclinic trough in the westerlies evolved into a deep low-pressure area in the central North Atlantic, and this caused Lisa to begin to accelerate to the northeast, with Lisa's foward speed reaching 50 knots on the afternoon of October 9. Shear relaxed over Lisa, and as a result, Lisa gradually strengthened. Late on October 9, Lisa turned to the north again. Lisa briefly strengthened into a Category 1 hurricane with 75 mph winds later on October 9 before merging with another extratropical frontal boundary in the far North Atlantic. On October 10, a well-defined circulation was not identifiable by satellite imagery.
Lack of Retirement
Because there was no damage, the name Lisa 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.