The origin of Tropical Depression Eleven can be traced to a tropical wave that moved off the west coast of Africa on 22 September. Little development occurred until the wave reached the western Caribbean on 30 September, when a broad low pressure area developed. Further development was slow as the system moved across the Yucatan Peninsula into the Gulf of Mexico, and it was not until 4 October that the system became a tropical depression about 125 n mi east-northeast of Veracruz, Mexico.
Steering currents were weak, and Tropical Depression Eleven meandered erratically over the Bay of Campeche throughout its lifetime (Figure 1). There was one notable reformation of the center between 0600 and 1200 UTC 6 October based on data from an Air Force Reserve Hurricane Hunter aircraft.
Development was hindered by a broad surface trough which dominated the central and eastern Gulf of Mexico, and the depression merged with the trough about 130 n mi northeast of Veracruz on 6 October. While ship reports and reconnaissance aircraft data indicate that tropical-storm force winds were present as the cyclone dissipated, these appear to have been associated with a wind surge moving southward over the western Gulf and not with the tropical cyclone.
Although the depression was poorly organized, it contributed to widespread and prolonged heavy rains over the Mexican states of Puebla, Tabasco, and Veracruz. Press reports indicate the resulting severe flooding was responsible for 400 deaths. It cannot be determined at this time how many of these were directly related to the rains from Tropical Depression Eleven.
Figure 1. Best track for Tropical Depression Eleven, 4-6 October 1999.
Table 1. Best track, Tropical Depression Eleven, 4-6 October 1999 Date/Time
(UTC)Position Pressure
(mb)Wind Speed
(kt)Stage Lat. (°N) Lon. (°W) 4/0600 20.1 94.1 1005 30 tropical depression 1200 19.5 94.0 1004 30 " 1800 19.0 94.0 1003 30 " 5/0000 18.9 93.8 1002 30 " 0600 19.1 94.2 1003 30 " 1200 19.4 94.5 1004 30 " 1800 19.6 94.8 1005 30 " 06/0000 19.6 95.0 1006 30 " 0600 19.5 95.4 1007 30 " 1200 20.4 96.4 1007 30 " 1800 dissipated 5/0000 18.9 93.8 1002 30 minimum pressure
