Tropical Storm Hermine

Preliminary Report
Tropical Storm Hermine
17 - 20 September 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)

a. Synoptic History

Hermine developed from a tropical wave which crossed Dakar, Senegal on 5 September and moved westward across the Atlantic. The wave was void of significant thunderstorm activity until it reached the Windward Islands where cloudiness and showers increased and there was a large 24-h pressure change on 12 September. The wave continued westward very close to the South American coast and then moved northwestward through the Northwest Caribbean Sea and the Yucatan Channel where a low pressure system developed. The system began to interact with an upper low in the Gulf of Mexico and another tropical wave which reached the area. During this period, a large and well-defined monsoon-type flow prevailed over Central America, the Northwestern Caribbean Sea and the Gulf of Mexico. It was not until 1200 UTC 17 September that the system acquired enough organization to be classified as a tropical depression.

The depression made a cyclonic loop over the central Gulf of Mexico while interacting with the upper-low located in the Bay of Campeche. The depression gradually became organized despite the unfavorable upper-level wind shear which prevailed in the area and reached tropical storm status at 1200 UTC 19 September. Hermine moved on a general northward track and made landfall as a weakening 40-mph tropical storm near Cocodrie, Louisiana at 0500 UTC 20 September.

b. Meteorological Statistics

There were no reports of tropical storm force winds near the area of landfall.

1. Rainfall Data

Hermine produced rains of about .5 to 1 inches

c. Casualty and Damage Statistics

There are no reports of casualty and damage from Hermine.

Maximum Intensity For Tropical Storm Hermine
17 - 20 September, 1998

Position Pressure
Wind Speed
Lat. (°N) Lon. (°W)
20/0000 29.0 90.9 999 45 Tropical Storm

Landfall for Tropical Storm Hermine
17 - 20 September, 1998
Wind Speed
Stage Landfall
20/0500 1000 40 Tropical Storm Cocodrie,