Tomorrow’s forecast: rain, in the shape of raindrops

A hi-tech upgrade to flood warning system will be able to identify precise size and pattern of downpours

A NETWORK of radars able to detect the precise shape and size of raindrops will provide better warnings of devastating floods, the Met Office has said.

An upgrade to the UK’S 15 hilltop detection stations means they can now alert forecasters to intense, localised downpours the previous system struggled to predict. Able to discriminate between rain, snow and hail, the technology will allow more locally specific warnings, giving people a chance to protect property or evacuate.

The network can now detect five times more data than before the fiveyear upgrade started, with an accuracy capable of identifying swarms of insects more than 25 miles away.

Industry data indicates insurers typically pay out anywhere between £1 billion and £4 billion to cover damage after a series of storms and heavy rain.

Last night, however, the Met Office said the radar improvements meant its four-day forecast was currently as accurate as the 24-hour service was two decades ago, giving property owners longer to prepare.

The organisation has operated 15 radars across the UK since 1974, with the first at Hameldon Hill near Burnley.

The upgrade involved enhancing old-fashioned dish technology with dome-shaped “doppler” radar which collectively can record 1.8million rainfall observations per hour. Individually they make about a million rotations each year and can measure rainfall up to 155 miles away.

Last night meteorologists said the upgrade would also allow more accurate wind forecasts.

Carol Holt, deputy director at the Environment Agency, which contributed to the upgrade, said: “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.

“This means people have more time to prepare when flooding is expected.”

Derrick Ryall, head of the Met Office Public Weather Service, said radar provided “the only means of measuring the spatial extent and distribution of rainfall over a wide geographical area”.

The completion of the overhaul will provide a welcome distraction for Met Office bosses, who have been dogged by controversy over the naming of weather events this winter and last. The organisation was criticised last month after it failed to name a storm that ended up battering the country with 95mph winds and heavy blizzards. Weather forecasts predicted that conditions in mid-january would not be severe enough to warrant being named, meaning many people were caught off guard by the wind and snow.

This week, long-range forecasting predicted a cold snap likely to last into the beginning of March, including two warnings for snow and ice.