New radar for Lewis will improve weather forecasts

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A new state-of-the-art radar, replacing the former weather radar at Lewis in the Western Isles opens this week.

The new radar can, for the first time, capture the size and shape of raindrops and snowflakes.

These new scientific advancements will ultimately lead to improvements in the accuracy of rainfall estimates, particularly during high impact weather events and they are the latest step by the Met Office to upgrade its 30 year old Radar Network.

The new radar has also begun to capture wind speed measurements. The network is one of the longest established radar networks of its kind in the world and consists of 15 radars across the UK.

Dave Jones Head of Observations says: “Weather radar provides the only means of measuring the spatial extent and distribution of rainfall over a wide geographical area.

“The most intense rainfall events are often highly localised and can therefore be missed or under-sampled by rain gauge networks, and whilst 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 radar at Lewis was originally opened in 1991 and is the most northerly radar in the network.

It is situated on a hill, in an area where peat is extracted for domestic heating. The hill was previously un-named, and the radar was initially named ‘Beacon Hill ’ by the Met Office.

However it was renamed following requests from local residents and given a Gaelic name instead. Druim ‘a Starraig (female) crow ridge (or alternatively Druim Na Starraig (Male) crow ridge)

The new radar system was developed in-house by Met Office engineers, combining world-leading hardware with unparalleled levels of skill and expertise.

Wherever possible equipment was sourced locally ensuring the project, while cost effective, also supported the local economy.

The new solution is based on ‘Open System Architecture’, which makes it more flexible than the previous network and more adaptable and easier to upgrade in the future as radar technology continues to develop.

The introduction of this ‘state of the art’ radar technology will help the Met Office to respond to present and future customer requirements. The solution also brought cost-savings as technology was developed in-house and is more efficient to operate.

The Met Office Weather Radar Network Renewal project is ensuring that we continue to play a vital role in providing governments, public and commercial customers with timely and essential weather forecast and real time weather information.

See a time-lapse video of the Lewis radar’s construction: here