 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 . 
