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, and the JMA upgraded it to Tropical Storm Imbudo on July 17. After becoming a tropical storm, Imbudo passed about 35 km (20 mi) north of Yap. The JMA upgraded Imbudo to a severe tropical storm late on July 18, around the same time that the JTWC upgraded it to a typhoon. An increase in outflow to the south and to the north from a tropical upper tropospheric trough (TUTT) caused a 36‑hour period of rapid development beginning on July 19. During that time, the JMA upgraded Imbudo to typhoon status, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) began issuing advisories as the storm approached the Philippines, and a 30 km (20 mi) wide eye formed. At 1200 UTC on July 20, the JMA estimated peak 10 minute sustained winds of 165 km/h (105 mph). At the same time, the JTWC estimated 1 minute sustained winds of 240 km/h (150 mph), making it a super typhoon. By late on July 20, the typhoon had developed concentric eyewalls, and the TUTT was moving away, thus diminishing outflow. Imbudo maintained peak winds for about 12 hours, before the innermost eye contracted to a diameter of 11 km (7 mi) in the midst of 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. Rapidly weakening over land, Imbudo emerged into the South China Sea about six hours after landfall. The JTWC estimated winds had decreased to 150 km/h (90 mph), although the agency estimated Imbudo quickly re-intensified to a secondary peak of 165 km/h (105 mph) in 1 minute winds. Dry air prevented convection from redeveloping significantly, and the eye had become large over open waters. At 0300 UTC on July 24, Imbudo made its final landfall west of Macau, near Yangjiang, Guangdong. It was the strongest to hit the province since Typhoon Sally in 1996, striking China with 10 minute winds of 140 km/h (85 mph), as estimated by the JMA. The storm rapidly weakened over land while moving over southern China. Late on July 25, Imbudo dissipated near the border of China and Vietnam. Preparations Before Imbudo struck, officials evacuated over 14,000 people to at