Hurricane Lenny began as a low-pressure area that was first observed in the southwestern Caribbean Sea on November 8. It developed an area of convection but remained poorly defined for the next few days. Thunderstorms spread across the region, producing heavy rainfall in portions of Mexico and Central America. On November 13, the system became better organized; a Hurricane Hunters flight later that day discovered a surface circulation and winds of about . The data indicated the development of Tropical Depression Sixteen at 1800 UTC, about south of the Cayman Islands. The depression's convection was fairly disorganized, and the National Hurricane Center (NHC) did not anticipate any strengthening for three days. For much of its existence, the tropical cyclone maintained a track from west to east across the Caribbean Sea, which was unprecedented in the Atlantic hurricane database, earning it the nicknames "Left-Hand Lenny" and "Wrong Way Lenny". The path resulted from its movement along the southern end of a trough over the western Atlantic Ocean.