Reports from the aircrew indicated that Ivan had strengthened to a strong category 3 (SSHS) hurricane as the center passed about 6 n mi south-southwest of Grenada. Air Force Reserve reconnaissance aircraft as the hurricane approached the southern Windward Islands. During that time, Ivan was under surveillance by U.S.

Immediately following the 24 h weakening period, Ivan began a second strengthening phase (Figure 2b) that also contained a 12 h period of rapid intensification. Conventional and microwave satellite data indicated the probable cause of the rapid weakening was due to mid-level dry air that got wrapped into the center of the hurricane and eroded the eyewall convection. However, almost as quickly as Ivan strengthened it also weakened - as much 20 kt over the following 24 h. This made Ivan the southernmost major hurricane on record. Satellite intensity estimates suggest that the intensity increased 50 kt while the central pressure decreased 39 mb during that time and Ivan reached its first peak intensity of 115 kt at 0000 UTC 6 September. After reaching hurricane strength, the rate of intensification increased dramatically and Ivan underwent an 18 h period of rapid intensification (rate > 30 kt/24 h). Ivan continued on a generally westward motion south of 10°N latitude and steadily strengthened, becoming a hurricane at 0600 UTC 5 September centered about 1000 n mi east of Tobago in the southern Windward Islands. Table 1 is a listing of the best track positions and intensities.ĭespite a relatively low latitude (9.7°N), development continued and it is estimated that the cyclone became Tropical Storm Ivan just 12 h later at 0600 UTC 3 September. The wind and pressure histories are shown in Figure 2a and Figure 3a, respectively. Figure 1 depicts the 'best track' of the tropical cyclone's path. Favorable upper-level outflow and low shear environment was conducive for the formation of vigorous deep convection to develop and persist near the center, and it is estimated that a tropical depression formed around 1800 UTC 2 September. However, by early on 1 September, convective banding began to develop around the low-level center and Dvorak satellite classifications were initiated later that day. Although the wave was accompanied by a surface pressure system and an impressive upper-level outflow pattern, associated convection was limited and not well organized.

Ivan developed from a large tropical wave that moved off the west coast of Africa on 31 August. Ivan caused considerable damage and loss of life as it passed through the Caribbean Sea. It was also the strongest hurricane on record that far south east of the Lesser Antilles. Ivan was a classical, long-lived Cape Verde hurricane that reached Category 5 strength three times on the Saffir-Simpson Hurricane Scale (SSHS). Hurricane Ivan 2 - 24 September 2004 Stacy R.

Ivan hurricane track