Cyclogenesis off the African Coast: The Case of Cindy in August 1999

Abstract

Abstract Using radar data from Dakar (Sengal), National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalyses, outgoing longwave radiation provided by the National Oceanic and Atmospheric Administration (NOAA) Television Infrared Observation Satellite (TIROS) satellite series as well as data from the National Hurricane Center (NHC), a cyclogenesis process leading to the birth of a tropical cyclone from a Sahelian mesoscale convective system (MCS) off the African coast of Senegal is described. The cause of this evolution seems to be the coincidence of the MCS with an easterly wave over a warm sea, the presence of a wide area of precipitable water vapor, strong convergence in the low and midtropospheric layers, and an easterly vertical shear of the zonal wind. As a result, a dynamically well organized convective system built up and the system rapidly strengthened. Before moving away from the African coast of Senegal, this perturbation, which became the tropical cyclone “Cindy,” caused the wreck of more than a hundred fishing pirogues and the deaths of many fishermen because of the suddenness and speed of the phenomenon.