 A tropical wave moved off the coast of Africa on July 27 as detected by <unk> imagery . By July 31 the tropical wave began being classified , using the Dvorak Technique , by satellite analysts at the National Hurricane Center , in part due to persistent deep convection . Shortly thereafter the system 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 . 
