Late on August 19, an area of low pressure developed north of Palau. Early on August 20, the system became more better organized and developed a low-level circulation center. The system then turned north and continued to drift north until on August 21, when the JMA upgraded the low pressure area to a tropical depression east of Philippines. The JTWC also issued a Tropical Cyclone Formation Alert (TCFA) on the system reporting that the system was becoming more well organized. Later that day, the PAGASA started monitoring the system as a tropical depression and named it "Mina". Late on August 22, the system became more well organized prompting the JTWC to initiate advisories on the system, designating it with "14W". On August 23, the JMA upgraded 14W to a tropical storm, naming it "Nanmadol". Overnight, the system continued to intensify and early on August 24, the JMA upgraded Nanmadol to a severe tropical storm. Later that day, convective banding improved and Nanmadol developed an eye-like feature. As a result, Nanmadol continued to intensify rapidly and became a typhoon, by midnight, that day. Nanmadol continued to drift northeast and made landfall over Gonzaga, Cagayan, Philippines with strong winds of over . Nanmadol weakened significantly after interacting with land and early on August 28, the JMA downgraded Nanmadol to a severe tropical storm. Late on August 28, Nanmadol made its second landfall over Taimali in the Taitung County of Taiwan and started weakening. Landfall weakened the system rapidly prompting the JMA to downgrade Nanmadol to a tropical storm with winds of under . Soon it started experiencing strong wind shear and continued weakening. The shear pushed convection about south of the LLCC. The system also accelerated towards China at and weakened to a minimal tropical storm. After its third landfall over Fujian, China, Nanmadol weakened rapidly prompting both the JTWC and the JMA to issue their final warnings on the system.