A NEW weather radar which can capture the size and shape of raindrops and snowflakes has been installed at Dean Hill, near West Dean.

Heavy lifting gear was used on Friday to crane the radar dish into position on top of a 22 metre tower before it was then enclosed in a golf ball-like radome.

Originally opened in 2005, the radar network which covers Wiltshire, Hampshire and across the channel, is in fact 30 years old.

The upgrade, a joint venture between the Met Office Public Weather Service and the Environment Agency, involves the installation of dual polarisation technology, a new radar system developed by Met Office engineers.

Katie Norman from the Met Office said: "The installation all went smoothly - we had to find a period of time when it wasn't too windy, it was the day after Storm Doris.

"The new technology will enable us to understand the shape and size of rain drops much better than we could before and that will mean we have much more accurate rainfall estimates."

The new radar has also begun to capture wind speed measurements.

"The radar is one of several networks of observing equipment which we operate at the Met Office," Ms Norman says. "Observations are absolutely fundamental to the work we do.

"The data recorded is also available to the Environment Agency which uses it in models for rivers and river catchments to allow them to better forecast and warn of flooding by rivers."

The radar has been switched off since October 17 and will be returned to operational use in May following a series of quality checks on data.

The network is one of the longest established radar networks of its kind in the world and consists of 15 radars across the UK.

Factbox

  • The radar dish is 3.7 metres in diameter
  • It makes about 1,000,000 rotations per year
  • It measures rainfall up to 250km away
  • It can record 1,800,000 rainfall observations per hour
  •  The new radar can discriminate between rain, snow and hail and provide improved rainfall estimates
  • The smallest echo detected is about 100,000,000,000,000,000 times fainter than the outgoing signal
  • Five times more data (1 terabyte) is received from the new radar, every year
  • The new radar has a lifetime of around 25 years