Historic Flooding Strikes Joso, Japan, in Wake of Etau

By Eric Leister, Meteorologist

September 11,2015; 9:32PM,EDT

 

 

Days of heavy rainfall have left parts of Japan dealing with historic flooding as rain from former Tropical Storm Etau finally diminishes.
Rainfall totals of 150-300 mm (6-12 inches) were common across southern and central Honshu with localized amounts exceeding 600 mm (24 inches).

Thousands Evacuated as Floods Hit Central Japan

The heaviest rain shifted into northern Honshu Thursday night and Friday averaging 50-100 mm (2-4 inches); however, locations such as Sendai received more than 250 mm (10 inches) of rain.
A truck and a house are damaged after floods hit Joso, Ibaraki prefecture, northeast of Tokyo, Friday, Sept. 11, 2015. The sun came out a day after a raging river washed away houses and forced people to rooftops as dozens of residents were airlifted out by military helicopters Friday morning after waiting overnight in the city. (AP Photo/Shizuo Kambayashi)
Some of the hardest-hit parts of Japan include Ibaraki and Tochigi prefectures, located northeast of Tokyo. Nasushiobara in Tochigi Prefecture reported more than 550 mm (22 inches) of rain in only 24 hours from Wednesday into Thursday.
Vehicles drive through a flooded street in Joso, Ibaraki prefecture, north of Tokyo, Thursday, Sept. 10, 2015. Raging floodwaters broke through a flood berm Thursday and swamped the city north of Tokyo, washing away houses, forcing dozens of people to rooftops to await helicopter rescues. (AP Photo/Shizuo Kambayashi)
Rainfall rates greater than 50 mm (2 inches) per hour were recorded across these prefectures on Thursday as the Kinugawa River broke through a flood berm sending a surge of flood waters rushing into the city of Joso.
The flood waters began rushing into the city of 60,000 people at 12:50 p.m., local time, according to the Associated Press.
Japan Ground Self-Defense Force performing a rescue in Ibaraki Prefecture on Thursday (Twitter/JGSDF_pr).
Flood waters more than a story deep have been reported in the city leading to numerous aerial rescues as people took refuge on the roofs of buildings.
Flood waters remained in some parts of the city on Friday even as dry weather returned to the region.
Rescue efforts continued into Friday with more than 280 people being air rescued from rooftops. At least 22 people remained missing with more than 3,500 living in temporary evacuation centers across the city.
Accuweather Meteorologist Anthony Sagliani added, "Heavy rain will come to an end across most of central and northern Honshu Friday night, though a few showers will linger. Tropical Storm Kilo will bring rain and some wind to far northern Hokkaido and the Kuril Islands of Russia, but areas facing flooding now will be spared from any of Kilo's rain."
RELATED:
Japan Weather Center
Detailed Forecast for Joso
Interactive Japan Weather Radar
Even though the worst flooding was reported north of Tokyo, the city has received more than 250 mm (10 inches) of rain since Tuesday leading to localized flooding and numerous travel delays. Normal rainfall for the entire month of September is only 181 mm (7.13 inches).
Mudslides and strong winds are responsible for at least three deaths and 27 injuries across Japan this week in addition to the flooding disaster in Joso, according to Japan's Fire and Disaster Management Agency.
Largely dry weather is expected across the worst hit areas of Japan through Saturday; however, frontal boundary will bring the threat for showers and thunderstorms on Sunday.