On June 15, the JTWC started to monitor an area of disturbed weather that was about 1350 km (835 mi), to the southeast of Manila, Philippines. Over the next couple of days the system gradually developed further, before late on June 16, the JMA, JTWC and PAGASA, all reported that the system had developed into a tropical depression, with PAGASA naming it as Egay. Egay continued to develop during June 17 as it moved towards the northeast, and on June 18 the JTWC reported that Egay had intensified into a tropical storm. Late on June 19, the JTWC downgraded Egay to a tropical depression, but they upgraded Egay again to a tropical storm on June 20. Early on June 20, the JTWC downgraded Egay to a tropical depression again. On June 21, the JMA upgraded the system into a tropical storm and named it Haima, with the JTWC following suit on June 22.