Japan seeks early alert system for freak rains

WITH an eye on the Tokyo 2020 Olympics, Japanese researchers are developing a new system to accurately forecast torrential downpours — known in Japan as “guerrilla rainstorms” — 30 minutes before they strike.

Scientists have created a hightech radar capable of producing a 3D map of a rain cloud in 30 to 60 seconds. They say this is a significant improvement on existing systems that measure only parts of a cloud in up to five minutes.

Along with the radar, installed last year at Saitama University, just north of Tokyo, the team is also using radio waves to estimate the amount of water vapor in the air to improve their forecasts.

The waves slow down depending on the volume of vapor in the air, making for a more accurate forecast, said Katsuhiro Nakagawa, director of the Remote Sensing Laboratory at the National Institute of Information and Communications Technology.

Japan is one of the most seismically active regions in the world and routinely experiences severe natural disasters, including earthquakes, floods and landslides that kill dozens of people every year.

The nation has created sophisticated early-warning technology and disaster mitigation systems and regularly holds emergency drills.

Sudden, localized torrential rains can cause killer flash floods, submerge roads in low-lying areas, or overflow drainage systems.

Organizers of the Tokyo 2020 Olympics and this year’s Rugby World Cup have voiced concern extreme weather phenomena such as a typhoon or heatwave could throw events into chaos.

(AFP)