Life-threatening rain in western Japan triggers first alert on par with level 5 warning

TOKYO -- The Japan Meteorological Agency (JMA) on July 20 raised its heavy rain emergency warning for the island of Tsushima and the Goto Islands in western Japan to the equivalent of level 5 -- requiring immediate action to prevent loss of life.

The agency raised the warning level at 10:05 a.m. on July 20 amid predictions of record volumes of rainfall in the areas. The islands, part of Nagasaki Prefecture, are the first places in the country to be subject to the equivalent of a level 5 warning, the highest on a five-level scale that was introduced in May in response to lessons learned from deadly torrential rains in western Japan in July 2018.

A JMA level 5 warning indicates that disasters such as flooding, landslides or rivers bursting their banks are very likely to occur imminently. While all residents are expected to evacuate once the preceding level 4 warning is issued, at level 5 all of those who have not done so are strongly advised to take immediate action to avoid loss of life.

At a news conference convened at 11 a.m. on July 20, JMA Forecast Division Director Yasushi Kajihara stated, "This is a situation in which it is essential for people to immediately take all appropriate measures to protect their lives. The chances of a disaster having already occurred are extremely high. At this stage, rather than people thinking they must go to a specified evacuation center, we want people to at least try to ensure their safety by going somewhere away from rivers and cliffs."

The special torrential rain warning was specifically issued for the city of Goto, the town of Shinkamigoto, parts of the city of Saikai, the town of Ojika, parts of the city of Sasebo and the city of Tsushima. Orders to evacuate were given for all parts of the city of Goto, with other municipal authorities in affected regions issuing evacuation advisories.

According to the JMA, as of noon on July 20, Typhoon Danas, the fifth typhoon of the year, was located west of the Korean Peninsula and heading north-northeast. Cumulonimbus clouds are said to be gathering in the regions near Tsushima and the Goto Islands, causing heavy rain to lash the region repeatedly over short periods of time.

The cities of Tsushima and Goto received over 100 millimeters of rain in an hour -- a record breaking amount for such a short period. Shinkamigoto was hit with 344.5 millimeters in the 12-hour period ending at 10 a.m. on July 20. The city of Goto recorded 312 millimeters for the 12-hour period ending at 10:10 a.m., with each area seeing its record for rainfall in a 12-hour period in July broken.

A road in the Tsuwazaki district in the northern part of Nakadori Island was reportedly cut off by a landslide, leaving over 100 households isolated. In the city of Goto on Fukue Island, a house is said to have been hit by a landslide from the hill behind it. Its residents reportedly evacuated and are safe.

The JMA is projecting that the northern part of Kyushu will be subject to between up to 150 and 200 millimeters of rain over the 24-hour-period ending at midday on July 21, and is calling for continued caution.

(Japanese original by Makoto Kakizaki, Yu Yoshizumi, Ken Nakazato, Kyushu News Department and Mayumi Nobuta, Science & Environment News Department)