In the middle of February 2004, a monsoon trough formed in the southwest Pacific Ocean during the middle of a Madden–Julian oscillation pulse. A low pressure area developed along the trough, and the Fiji Meteorological Service (FMS) designated it Tropical Disturbance 5F on February 21 about halfway between Vanuatu and Fiji. Initially, the system was moving little and had a circulation that was detached from the primary area of convection. On February 22 after the thunderstorms increased, the Joint Typhoon Warning Center (JTWC) initiated advisories on the disturbance with the designation Tropical Cyclone 13P. Shortly thereafter, the FMS reported that the disturbance developed into a tropical depression, although the convection was transient and displaced from the circulation. The system tracked west-northwestward, due to a ridge located to its south. With low wind shear and good outflow, the system gradually organized, with the circulation becoming situated underneath the convection. At 0300 UTC on February 23, the FMS upgraded it to a tropical cyclone and gave it the name Ivy while the storm was about 510 km (315 mi) northeast of Port Vila, Vanuatu.