Hurricane Lisa was the twelfth named storm and ninth hurricane of the 2004 Atlantic hurricane season. Lisa formed on September 19 in the far eastern Atlantic Ocean well to the west-southwest of the Cape Verde Islands. Lisa moved west, made a cyclonic loop, moved north-northwest, north, northwest, then northeast, where it briefly became a hurricane before weakening back to a tropical storm and becoming extratropical on October 3.
Lisa caused no damage and no deaths.
|Formation||September 19, 2004|
|Dissipation||October 3, 2004|
|Highest winds||75 mph|
|Lowest pressure||987 mbar|
|Part of the||2004 Atlantic hurricane season|
Lisa's origins can be traced back to a tropical wave that moved off the coast of Africa on September 16. Early on September 19, the wave gained enough organization to warrant a Dvorak classification, and later that day, at approximately 1800 UTC, it organized further, becoming Tropical Depression Thirteen while located 450 miles west-southwest of the Cape Verde Islands. After forming, the depression moved westward at 10 knots. The environment was not particularly favorable for strengthening - the depression was located between Hurricane Karl to the west-northwest as well as a large and convectively active tropical wave to the southeast. In spite of outflow from Hurricane Karl impinging on the northern portion of the depression, the depression developed a small inner core, and it strengthened rapidly on September, becoming Tropical Storm Lisa at 1200 UTC that day. 18 hours later, Lisa's winds reached 70 mph. The northerly wind shear from the outflow of Karl prevailed, and Lisa gradually weakened over the next couple of days while heading across the open Atlantic Ocean well away from any land areas. Meanwhile, the aforementioned convectively active tropical wave was approaching Lisa from the east, and the two systems underwent a Fujiwhara interaction. On September 22, Lisa turned to the south, and then to the east on September 23 as convection from the two systems became hard to distinguish. Although Lisa weakened to a tropical depression on September 23, it was able to maintain a small but distinct low-level circulation center throughout its merger with the disturbance. Early on September 24, Lisa completed a cyclonic loop and briefly regained tropical storm status before northerly shear separated the cyclone from the deep convection once again. Lisa turned sharply to the north on September 25 ahead of a deep-layer mid- to upper-level trough moving southeastward into the central Atlantic Ocean. The northerly wind shear weakened, and Lisa regained tropical storm status for a third time at 0600 UTC September 25 while located 925 miles east of the Lesser Antilles. Lisa moved to the north for five days as a tropical storm, and it nearly attained hurricane status on September 29 when an upper-level trough in the westerlies cut off to the southwest of the cyclone, reducing the southwesterly vertical wind shear over the storm. During this time, satellite imagery showed a ragged eye ringed by shallow convection.
Lisa on September 29.
On September 30, Lisa passed over cooler water upwelled by Hurricane Karl. During this time, Lisa's convection decreased, and the winds dropped to 50 mph, even though the eye feature remained distinct. On October 1, Lisa turned to the northeast and accelerated ahead of an approachiing shortwave trough in the westerlies. Southwesterly wind shear decreased over the storm, and Lisa re-strengthened over 25°C waters. Early on October 2, cloud tops cooled significantly within the cyclone around the eye and Dvorak estimates were as high as 77 kt. Based on satellite estimates, it is estimated that Lisa became a hurricane, after existing for 13 days as a tropical cyclone, at 0600 UTC October 2 while located about 625 miles southeast of Cape Race, Newfoundland. At this time, water temperatures underneath the cyclone were a cold 23°C. Lisa was a hurricane for less than 12 hours before the cloud pattern began to deteriorate rapidly. By 0600 UTC October 3, Lisa transitioned into an extratropical cyclone, and was absorbed into a frontal low a few hours later while located about 1000 miles east-southeast of Cape Race, Newfoundland.
Lisa spent 11¾ days as a tropical storm between it forming on September 20 and it reaching hurricane status on October 2, which is the longest time ever observed in the Atlantic for a tropical storm to reach hurricane status. Hurricane Dennis of 1981 took longer overall to reach hurricane status, but it degenerated into a tropical wave before becoming a tropical cyclone again, thus it is not counted as the tropical cyclone that holds the record for the longest duration between a tropical storm and a hurricane. Lisa's total development time from a tropical depression to a hurricane, at 12½ days, is second only to Hurricane Josephine during the 1990 Atlantic hurricane season.
Lack of Retirement
Due to the lack of any damage, the name Lisa was not retired in the Spring of 2005 by the World Meteorological Organization. It is on the list of names to be used for the 2010 Atlantic hurricane season. Once again, no damage or deaths, so it will be used again for the 2016 Atlantic hurricane season.