Tropical Storm Bilis - Meteorological History

Meteorological History

A tropical disturbance developed northeast of Yap on July 7 and slowly increased in organization. The Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert on the disturbance later that day as it moved northwestward. By July 8, it had developed sufficient convection to be designated a tropical depression by the JTWC and the Japan Meteorological Agency (JMA). The depression continued to strengthen, and was designated Tropical Storm Bilis by the JMA early on July 9. The JTWC upgraded Bilis to tropical storm status later that day. On July 10, Bilis moved into the area of responsibility of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), and was designated Tropical Storm Florita for local warnings.

Over the next several days, Bilis moved generally northwestward toward Taiwan, slowly strengthening over open waters. Bilis was designated a severe tropical storm by the JMA on July 11, but the storm did not strengthen much further over the next few days due to a marginal upper-air environment and dry air entrainment. PAGASA upgraded the system to typhoon status on July 12, but the JMA never officially recognized the system as such in its advisories. Bilis reached its official peak intensity of 60 knots (110 km/h, 70 mph) later that day.

Bilis made its first landfall in northern Taiwan on July 13, with an intensity of 55 kt (100 km/h, 65 mph). After moving across northern Taiwan, Bilis made its second landfall in Fujian, China early on July 14 at the same intensity, then weakened into a tropical depression over land the next day. Bilis lingered as a tropical depression over southeastern China before degenerating into a remnant low on July 16. Despite becoming a remnant low, the remnants of Bilis maintained their identity for several days while moving westward over China, bringing heavy rains to inland areas.