Tropical Depression Twelve was a tropical depression during the 1999 Atlantic hurricane season that did not become a tropical storm. It formed from a tropical wave that exited the coast of Africa on September 30. The depression dissipated on October 8, only two days after becoming a tropical depression.
The depression caused no known damage or fatalities.
|Formation||October 6, 1999|
|Dissipation||October 8, 1999|
|Highest winds||35 mph|
|Lowest pressure||1007 mbar|
A tropical wave exited the coast of Africa on September 30. Dvorak classifications began on the wave on October 3. Based on satellite estimates and cloud drift wind vectors from the University of Wisconsin, the wave is estimated to have become Tropical Depression Twleve on October 6. After forming, the depression moved somewhat eratically to the west-northwest for the next three days without strengthening further. During this time, the low-level circulation was mostly on the west side of the deep convection, due to the presence of an upper-level trough/low to the north of the cyclone. On October 8, convection associated with the depression diminished, and the depression dissipated as the low-level circulation became less-defined. The remnant low-level cloud swirl could be tracked for several days thereafter as it continued west-northwest and then westward before it dissipated completely north of the Lesser Antilles.