Hurricane Jeanne 1998

Preliminary Report
Hurricane Jeanne
21 September - 04 October 1998


Tropical Storm Alex (TS)
Hurricane Bonnie (3)
Tropical Storm Charley (TS)
Hurricane Danielle (2)
Hurricane Earl (2)
Tropical Storm Frances (TS)
Hurricane Georges (4)
Tropical Storm Hermine (TS)
Hurricane Ivan (1)
Hurricane Jeanne (2)
Hurricane Karl (2)
Hurricane Lisa (1)
Hurricane Mitch (5)
Hurricane Nicole (1)

Jeanne remained over the eastern Atlantic. It brushed the Cape Verde Islands, and also caused some gusty winds over the Azores just before losing tropical characteristics.


a. Synoptic History

Jeanne formed from a tropical wave that was slow to emerge from western Africa. The associated disturbed weather lingered near the African coast from the 19th through the 20th of September, and gradually became better organized. An initial Dvorak classification was made by the Tropical Prediction Center's Tropical Analysis and Forecast Branch (TAFB) at 1800 UTC 19 September, locating a center about 120 nautical miles offshore of the coast of Guinea. Only a slight increase in organization and little motion was noted during the following 24 hours. By 0600 UTC 21 September, deep convection had increased and it is estimated that the system had become a tropical depression, while centered about 140 nautical miles southwest of the coast of Guinea-Bissau.
According to National Hurricane Center (NHC) records beginning in 1886, only Tropical Storm Christine of 1973 formed farther east than Jeanne in the Atlantic basin.

The cyclone moved generally west-northwestward, gradually strengthening into a tropical storm later on the 21st. Jeanne was situated in an environment of slight east to southeasterly shear, which is typical for systems in the eastern tropical Atlantic. Early on the 22nd, Jeanne began to intensify at a faster pace, and by 1800 UTC that day is estimated to have become a hurricane while centered about 120 nautical miles southwest of the Cape Verde Islands. This was the closest point of approach to those islands. For the next couple of days, Jeanne continued moving toward the west-northwest, strengthening to its estimated peak intensity of 104 mph while located about 580 nautical miles west of the westernmost Cape Verde Islands. The forward speed slowed, from 15-20 mph the previous couple of days, to near 12 mph, and the hurricane turned toward the northwest, and then north, on 25-27 September. Jeanne weakened, mainly due to increased southwesterly vertical shear, on 25-26 September. These events were likely caused by an amplifying mid- to upper-tropospheric trough located about 10 degrees of longitude to the west, a feature which assured that Jeanne would remain in the eastern Atlantic for its life cycle.

Under the continued influence of the trough, Jeanne accelerated toward the north-northeast on 28 September. The hurricane re-intensified somewhat, to near 92 mph, while located about 550 nautical miles west-southwest of the Azores. As the system turned toward the northeast and east-northeast on the 29th, its forward speed slowed and it weakened to a tropical storm. Jeanne continued toward the east-northeast while gradually weakening. Around 0000 UTC 1 October, the cyclone reached the Azores, but had degenerated to a depression that was losing tropical characteristics. After leaving the Azores, the extratropical low moved eastward, generating an area of gale force winds until reaching the coast of Portugal just north of Lisbon around 0000 UTC 4 October. Jeanne's extratropical remnants became unidentifiable over Spain later that day.

b. Meteorological Statistics

Jeanne's peak intensity of 104 mph on 24 September is based on subjectively-derived Dvorak T-numbers of 5.0 from the TAFB and the SAB. A French drifting buoy, identifier 41599, reported winds of 060°/63 mph, 060°/55 mph, 110°/86 miles near 23.3N 40.6W at 1000, 1100, and 1900 UTC, respectively, on 26 September. Although this buoy's data are considered questionable, the 86 mph wind was used for the best track intensity, since it was reported very near the center of the hurricane where a burst of deep convection was occurring at the time. A ship, call sign GQVJ, reported winds of 170°/41 mph at 30.1N 37.9W at 1200 UTC 28 September. Another ship, with call sign C6KV2, also reported winds of 170°/41 mph, at 32.4N 35.4W at 1800 UTC 28 September.

The island of Horta in the Azores reported wind gusts to 39 mph around 1800 UTC 30 September.

c. Casualty and Damage Statistics

There were no known casualties or damages caused by Jeanne.

Maximum Intensity For Hurricane Jeanne
21 September - 04 October, 1998

Position Pressure
Wind Speed
Lat. (°N) Lon. (°W)
24/1800 17.0 35.4 969 105 Category 2 Hurricane