Preliminary Report
Tropical Depression Eleven
4 - 6 October 1999

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