Updated on Monday, November 17, 2008, 00:00 IST

Tokyo, Nov 17: Two research institutes in Japan have jointly developed technology to foretell areas which might be hit by strong winds an hour ahead of time by using a radar observation network in the Tokyo metropolitan area, researchers said on Monday.

The technology by the Japan Weather Association and the National Research Institute for Earth Science and Disaster Prevention could be applied to a system to predict the emergence of heavy rains, which is effectively unavailable under the current weather forecast technology, they said.

The two institutes will report the findings at a three-day meeting of the Meteorological Society of Japan from Wednesday in Sendai.

The new technology involves the radar network called ''X-Net'' that monitors wind and rainfalls with the use of the latest models of ''doppler radars'' set up in five locations in and around Tokyo.

Used in air defence and air traffic control, a doppler radar employs the doppler effect of the returned echoes from targets to measure their radial velocity.

According to the researchers, the technology foretells areas to be hit by a gale measuring 54 kilometres per hour or stronger after the radars monitor rain drop movements in the clouds by sending radio waves.

The technology can analyse the volume of rainfalls more precisely than the Japan Meteorological Agency's radar system. Two types of radio waves have found that rain drops change their round shape to a flat shape in the event of greater rainfalls.

Currently, the meteorological agency issues storm warnings and gale warnings when wind velocity exceeds a certain level. But the agency has yet to predict where a gale is generated.

Bureau Report