On July 15 , the JMA estimated that a tropical depression formed , and the next day the JTWC initiated advisories on Tropical Depression 09W about 665 km ( 415 mi ) east of Yap . A subtropical ridge near Okinawa steered the nascent depression to the west @-@ northwest for much of its duration . With warm waters and favorable upper @-@ level conditions , the depression quickly organized , first to Tropical Storm Imbudo on July 17 , and to typhoon status two days later , when PAGASA begin issuing advisories on Typhoon Harurot . Around that time , Imbudo was rapidly intensifying , developing a well @-@ defined eye . At 1200 UTC on July 20 , the JMA estimated peak 10 minute sustained winds of 165 km / h ( 105 mph ) , and the same time , the JTWC estimated 1 minute sustained winds of 240 km / h ( 150 mph ) , making it a super typhoon . Imbudo maintained peak winds for about 12 hours , before undergoing an eyewall replacement cycle . At 0300 UTC on July 22 , Imbudo struck northern Luzon , with 1 minute winds estimated at 205 km / h ( 125 mph ) by the JTWC . It weakened over land , but re @-@ intensified in the South China Sea , striking southern China near Yangjiang , Guangdong on July 24 . Imbudo rapidly weakened , dissipating on July 25 .