Extreme Rainfall Hits Ishikawa and Toyama Prefectures in Japan

Heavy rain caused by a linear precipitation zone struck the Hokuriku region of Japan, specifically Ishikawa and Toyama prefectures, starting in the early hours of August 27. In Himi, Toyama, 361.5mm of rain fell within 24 hours, which is equivalent to half the average annual rainfall of London and Paris. The Japan Meteorological Agency issued its highest level rain warning and landslide warnings, leading to the evacuation of hundreds of thousands of people.

The rainfall caused several rivers to burst their banks, resulting in flash floods and mudslides. In Toyama, the Manio River overflowed, causing extensive flooding in Himi City. One local lumber company reported the loss of five forklifts, trucks, and machinery worth approximately 50 million yen. In Ishikawa, the Shio River overflowed in Hakui City, where a local resident reported that sediment has raised the riverbed by about three meters. A local supermarket in Hakui City was flooded under 50 centimeters of water, forcing the business to suspend operations and discard approximately 500 types of products.

As of the evening of August 28, 142 people across four districts in Hodatsushimizu Town, Ishikawa, and 110 people across six districts in Himi City, Toyama, remained isolated. Authorities confirmed 115 buildings with floor level flooding in Ishikawa and 169 buildings in Toyama. One woman in her 70s in Komatsu City sustained a minor head injury after falling while attempting to sweep water out of a business entrance. Volunteers have begun mud removal efforts in affected settlements.

Meteorological analysis suggests that the developing El Nino may explain the increase in extreme rain events and storms approaching Japan this year. This weather pattern allows weather fronts to push through more easily and tropical storms to recurve toward the island nation. This event follows other recent weather extremes in the region, including the passage of Typhoon Saudel through Kagoshima and Okinawa Island.