National Hurricane Center
A tropical wave moved off the coast of Africa on July 27, as detected by Meteosat imagery. By July 31 the tropical wave began to be classified, using the Dvorak Technique, by satellite analysts at the National Hurricane Center, in part due to persistent deep convection. Shortly thereafter, the system became organized enough that the National Hurricane Center began classifying it as Tropical Depression Five, roughly halfway between Cape Verde and the Lesser Antilles. The depression moved westward at 17 mph (28 km/h), intensifying as it did so, and eventually intensified enough to be upgraded to a tropical storm, which was named "Dean" by the National Hurricane Center.