Typhoon Sanba, known in the Philippines as Typhoon Karen, was the strongest tropical cyclone worldwide in 2012. The sixteenth named storm and tenth typhoon of the annual typhoon season, Sanba formed as a tropical depression east of The Philippines on September 10. The storm gradually intensified as it moved generally northward in an area favorable for tropical development. The system was soon upgraded to a tropical storm less than a day after formation and subsequently further to a typhoon on September 12. Later that day, Sanba entered a phase of explosive intensification, quickly strengthening and gaining annular characteristics. On September 13, the system attained its peak intensity with maximum sustained winds of 125 mph, and a barometric pressure of 900 mbar, becoming the strongest typhoon in the Western Pacific Ocean since Megi in 2010. Accelerating towards more northerly latitudes, a period of gradual weakening ensued afterwards as its eye expanded. It made landfall on South Korea late on September 17 as a typhoon before transitioning into an extratropical cyclone the following day. Sanba's remnants tracked into the Primorsky Krai region of eastern Russia before they were last noted on September 19. Passing just to the west of Japan, Sanba caused extensive losses to agriculture, forestry, and fishing industries on the islands of Okinawa Prefecture. Further inland on Kōchi and Gifu Prefectures, heavy rains damaged agricultural regions and washed out numerous roads. Losses on both prefectures totalled to ¥1.55 billion. Upon its landfall on the Korean Peninsula on September 17, it became the first time in 50 years that the peninsula had been struck by at least four typhoons in a single year. In South Korea, torrential rainfall also washed out road systems and inundated crop land, as well as damaged infrastructure. Losses there associated with Sanba totaled to ₩389 billion. In North Korea, the heavy precipitation worsened preexisting flood conditions initially started by Tropical Storm Khanuntwo months prior. Overall, throughout the typhoon's nine-day trek, Sanba caused US$378.8 million in losses and killed six people.
In Kōchi Prefecture, 222 hectares of agricultural land was damaged by the storm, with losses reaching ¥50 million. Throughout Okinawa, damage to agriculture, forestry, and fisheries amounted to ¥900 million. Heavy rains from the storm in Gifu Prefecture triggered numerous landslides and caused significant flooding that washed out hundreds of roads. Losses in the prefecture reached ¥1.5 billion.
South Korea
Across South Korea, heavy rains from the storm washed out numerous roads and flooded cropland. Numerous structures along rivers were damaged or destroyed by flooding. Losses from the typhoon reached ₩389 billion.
