A tropical wave moved off the west coast of Africa on September 22nd. Development occurred once the wave moved into
the western Caribbean sea on the 30th, spawning a broad surface low. The system slowly developed as it moved across the
Yucatan peninsula into the Bay of Campeche. On October 4th, the low finally gained enough organized thunderstorms to
be declared a tropical depression. The system meandered south until the 5th, before edging west-northwest towards
mainland Mexico. Very early on the 6th, the center redeveloped further westward due to easterly shear over the surface
circulation. As the cyclone linked up from a frontal boundary dropping down through its northeast and western periphery,
gale force winds were reported in the cold sector to its west and northwest.
Due to easterly shear over the system and onshore flow in its western quadrant, heavy rain fell across the states of Puebla,
Tabasco, Hidalgo, and Veracruz with a local maximum of over 40 inches reported. This depression ranks as the third
wettest tropical cyclone to impact Mexico since 1983, behind Wilma (2005) and Frances (1998). Due to the opening of
flood gates in the mountains because of previously heavy rains in September, the flood which struck between October
5th and 7th became the worst in the area during the past 40 to 400 years. As of 2006, the region was still recovering
economically from the flood. The death toll estimates range between 384 and 1100. Rainfall information for Mexico
was obtained from the Comision Nacional del Agua, the parent agency of Mexico's national weather service.
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References
B. E. Aguirre, 2004.
Preliminary Paper #341: The 1999 Floods in Veracruz and the
Paradigm of Vulnerability.
Jack Beven, 1999.
National Hurricane Center Tropical Cyclone Report for Tropical
Depression 11.
Discovery
Channel Documentary. Flooded Civilization (2006).