Typhoon Nanmadol (2004)

Typhoon Nanmadol, known in the Philippines as Super Typhoon Yoyong, was the last of four consecutive tropical cyclones to strike the Philippines in 2004. A quickly moving system, Nanmadol brought heavy rainfall and strong winds over the same regions impacted by the previous storms, exacerbating flood conditions in Luzon and surrounding regions. Together Nanmadol and these systems accounted for around 1,000 deaths in the Philippines. The typhoon later became the first December tropical cyclone to strike Taiwan since record keeping began, bringing along with it heavy rain, which also affected nearby regions of eastern China. As an extratropical storm, Nanmadol brought gusty winds and rain to Japan.

Nanmadol developed from an isolated area of convection south-southwest of Pohnpei that became classified as a tropical depression on November 28. Within highly conducive conditions for development, the system reached tropical storm intensity the following day, followed by typhoon intensity on November 30. Quickly pacing towards the north-northwest about the periphery of a nearby subtropical ridge, Nanmadol reached its peak intensity on December 1 with winds of 165 km/h (103 mph) and a minimum barometric pressure of 935 mbar (hPa; 27.61 inHg). Shortly after, the typhoon made landfall at a similar intensity on Casiguran, Aurora, quickly moving over Luzon before reaching the South China Sea, where it recurved northward into hostile atmospheric conditions. Over the next few days, Nanmadol weakened and later transitioned into an extratropical cyclone near Taiwan on December 4, whereafter it merged with another extratropical system.

With the typhoon approaching landfall in an area still recovering from previous storms, relief agencies already servicing the region were forced to allocate additional resources to prepare for Nanmadol. Evacuation efforts assisted in moving almost 100,000 people into shelters. Effects from Nanmadol were most severe in Cagayan Valley, where 14 people were killed. Power outages were widespread across several islands. Overall, damage from the typhoon in the Philippines totaled ₱2.23 billion (US$39.3 million). Heavy rainfall, peaking at 1,090 mm (43 in), was documented in Taiwan. Agricultural damage in Taiwan alone reached NT$670 million (US$20.8 million). Similar effects were felt in Japan, where the remnants of Nanmadol produced record-breaking rainfall and wind. Damage was particularly significant in Aichi Prefecture, totaling JP¥69.8 million (US$680,000). Overall, Nanmadol resulted in 77 fatalities and US$60.8 million in damage across three countries.

The 2004 Typhoon Nanmadol is not to be confused with other typhoons of the same name that also happened in the northwestern Pacific Ocean in 2011, 2017, and 2022. The name Nanmadol was contributed by Micronesia and refers to the Nan Madol archaeological site on Pohnpei.