A tropical wave moved off the west coast of Africa on September 16. A low level center of circulation developed from a tropical disturbance spawned by this tropical wave midway between the African coast and the Caribbean on September 20. The next day, the system gained sufficient organization to become a tropical depression. The depression moved westward in excess of , and reached tropical storm strength-becoming Tropical Storm Lili as it passed through the Windward Islands. The cyclone continued to intensify as it moved west through the Caribbean Sea, reaching an initial peak strength of on the morning of September 24. This was immediately followed by an abrupt weakening, and the storm's maximum sustained winds dropped to later that day. The sudden weakening was attributed to strong southerly vertical shear. The system degenerated into an open tropical wave the next morning, and remained in that state for nearly two days.