70 Inches Of Rain Fell In Japan In Just Days

In the last two weeks, Japan has been inundated with rainfall totaling over 70 inches in areas over the extreme southwestern part of the country. This has been cited as one of worst flooding disasters to ever occur there. The flooding rains have lead to numerous landslides as well as rivers overflowing their banks which has caused immense damage to cities and villages. The death toll has risen to 200 and continues to rise by the day, with another 54 people that remain unaccounted for. The Hiroshima and Okayama Prefecture areas took the brunt of the storms, with rainfall rates exceeding three inches per hour at times. Japan’s Shikoku Island was also hit hard. The Associated Press reported that 10.4 inches of rain accumulated in its Kochi Prefecture in just three hours, with more than 70 inches of rain totaling at the end of the storm system. The World Meteorological Organization reports that the total precipitation at many of the observation sites reached two to upwards of four times the annual mean which also happens to be the monthly precipitation for the month of July in southwestern Japan.

Japan is no stranger to natural disasters, with the catastrophic tsunami in 2011 that caused the meltdown at the Fukushima Daiichi Nuclear Power Plant. The scenes of the flooded landscapes with rooftops just barely visible this past week eerily resembles the aftermath of the 2011 tsunami.

In the case of this storm, the torrential rainfall can be blamed on a combination of events occurring. Tropical moisture was pulled north, colliding with the remnants of Typhoon Prapiroon as well as colliding with a front stalled over Japan. While uncommon to occur, the atmospheric conditions were just right in this case, creating multiple storms behind the parent thunderstorms. This process had the storms lining up and inundating the same region over and over, causing the massive landslides and flooding to occur instantaneously.

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©2018 Weather Forecaster Michael Ames