The upgraded radar network is now so accurate that it can capture the size and shape of raindrops and snowflakes.
The Met Office and Environment Agency have invested in a £10m upgrade to the Met Office Radar Network to improve the accuracy of rainfall estimates especially during extreme weather events such as flooding.
The UK’s 15 radar stations (see picture of radar dome at Stornoway on the Isle of Lewis) will now be capable of: delivering five times more data than the old radar; recording 1.8m rainfall observations; and identifying swarms of insects or flocks of birds from 40km away.
The technology, which was developed by Met Office engineers, will also be able to gauge the size and shape of raindrops and snowflakes to provide more accurate rainfall forecasts.
"Weather radar provides the only means of measuring the spatial extent and distribution of rainfall over a wide geographical area," says Derrick Ryall, the head of the Met Office Public Weather Service.
"The most intense rainfall events are often highly localised and can therefore be missed or under-sampled by rain gauge networks, and while their occurrence can be forecast with skill, it is often not currently possible to forecast their exact location. Radar therefore provides a crucial input to short-range weather forecasts (nowcasts) of precipitation rate, and improves the skill of weather forecasts when it is assimilated into numerical weather prediction models.
"The quality and reliability of the data we are getting from the new radars is significantly improved and will help us to provide more accurate flood forecasts and issue flood warnings earlier," adds Carol Holt, deputy director for the EA.
"This means people have more time to prepare when flooding is expected – so please check whether your home is at risk and sign up to receive our free warnings."