Catastrophe modeling firm AIR Worldwide’s report on former Typhoon Halong notes that it was downgraded to a tropical storm before making its first landfall in Japan on Shikoku Island at approximately 6 a.m. Japan Standard Time (JST), 15:00 UTC on Sunday, August 10.
“Halong then tracked northward, crossed the Seto Inland Sea and made a second landfall on Japan’s main island of Honshu, at about 10 a.m. JST on Sunday,” AIR’s report said. “Record-breaking rainfall—in some cases, nearly 3 feet |1 meter] of rain was dumped on the affected region—prompted an emergency weather warning by the Japan Meteorological Agency (JMA) that resulted in the evacuation of half a million people.”
Dr. Anna Trevino, scientist at AIR Worldwide said: “As of Monday morning JST, Halong had transitioned to a post-tropical cyclone located at 43° North latitude and 137° East longitude over the Sea of Japan. Currently, Halong exhibits sustained winds of 56-111 km/h (35-69 mph). Flood warnings, however, remain in effect throughout Hokkaido, Japan’s northernmost major island.
“Halong lashed the region with high winds and torrential rains, including the major cities of Osaka, Kobe, and Kyoto. Record-breaking rainfall was recorded in Mie Prefecture—which was inundated by nearly 17 inches [432 mm] of rain in 24 hours—prompting an emergency weather warning by the JMA that triggered the evacuation of half a million people.”
AIR said the “maximum reported rainfall rate from Halong occurred in Kochi prefecture, which recorded a remarkable 33.94 inches [862 mm] of rain in 24 hours, and a total of 42.56 inches [1081 mm] in a 72-hour period. This extreme rainfall resulted in landslides in the prefecture, and is among the 10 largest 24-hour rainfall totals recorded in the region since the JMA installed its high resolution observation network in the mid-1970s.
“Damaged homes have been reported in Tochigi prefecture, north of Tokyo, primarily due to the storm’s heavy rain. Throughout Japan, hundreds of homes have been damaged by Halong, with the majority of damaged homes located in Kochi prefecture (located on Japan’s main island of Honshu) and Tochigi prefecture (located on the south coast of Shikoku Island).”
Dr. Trevino noted: “Following on the heels of Typhoon Neoguri, which impacted southern Japan a month ago, Halong inflicted further damage on the already saturated region. Taken together, Neoguri and Halong caused flood damage to over 2,000 homes across Japan, with both storms causing the most damage in Kochi prefecture. In addition, note that Halong followed a track path similar to that taken by Typhoon Roke in 2011, which caused major flooding and damaged over 3,000 homes; insured losses from Roke have been estimated at $1.1 billion, primarily as a result of flood damage.”
Along with the property damage it has inflicted, Halong disrupted travel associated with Japan’s annual Buddhist holiday of Obon. Hundreds of flights were canceled due to Halong. Bullet train service was also disrupted in parts of the affected region. Flooded roads further disrupted travel by car and the massive amount of rain dumped by Halong may cause additional landslides due to slope saturation.
Source: AIR Worldwide