A tropical wave moved off the west coast of Africa on October 3. It tracked westward, reaching the Caribbean Sea on October 10. By October 13, a large area of convection persisted from Hispaniola southwestward through Panama, and over the next few days the convection organized and concentrated in the northwestern Caribbean Sea. An anticyclone became established near Jamaica on October 15, which created a favorable upper-level environment for the system by reducing wind shear. Around the same time, a low-level trough emerged from the Intertropical Convergence Zone, heading north off the coast of Nicaragua. Early on October 16, the system developed into a broad tropical depression about halfway between Central America and Jamaica.