风切变
A tropical depression developed from another tropical wave on September 9. Surface observations and ship reports suggested that it developed into Tropical Storm Debby on September 10, despite poor organization evidenced by satellite imagery. Peaking with winds of , the storm moved westward through the Leeward Islands and encountered wind shear which limited the storm's intensity and organization. Wind shear caused the system to deteriorate, and the circulation degenerated into a tropical wave on September 11.