Due to become operational in summer 2022, the new machine is intended to provide six times the performance of the current setup.
The massive increase in processing power will let meteorologists predict weather changes on a much smaller scale, allowing towns and cities to prepare better for disruptive weather, the Met Office said.
Supercomputers can run trillions of calculations in parallel to crunch the huge amount of data necessary to track and predict weather. Recent notable gains in forecasting credited to supercomputers include the identification of storms Ciara and Dennis, plus the “Beast from the East”, several days before they hit Britain.
Forecasters said the new machine would “predict storms, select the most suitable locations for flood defences and predict changes to the global climate” more accurately than the incumbent, a trio of Cray XC40 systems installed in 2016 and for which support is due to end in September 2022.
It will also be used to beef up the UK’s capacity in artificial intelligence and other high-tech research, a Met Office statement said.
Professor Ted Shepherd, chair of the Science Review Group, said: “Improved daily to seasonal forecasts and longer-term climate projections will equip society with a greater ability to proactively protect itself against the adverse impacts of climate change.”
The new machine will also “help support the transition to a low carbon economy”, Met Office chief executive Prof Penny Endersby added. The government has pledged to make the UK carbon neutral by 2050.
Prof Endersby claimed in an interview with the BBC that the Met Office’s new computing power would put Britain’s forecasters “streets ahead of anybody else”.
Questioned about the possible power requirements of its new monster computer, the Met Office told The Independent it recognised the impact a machine of this scale – likely featuring hundreds of thousands of processing cores, plus storage, cooling and more – could have on the environment.
A spokesperson said: “The energy consumption will be entirely dependent upon the chosen solution. The Met Office has a long-standing commitment to environmental responsibility and recognises the impact of supercomputing on the environment.
“The Met Office will work with potential data centre suppliers to ensure they are able to meet our high expectations regarding energy efficiency and ensure whole life sustainability is considered.”
Hosting part of the system abroad “may enable us to take advantage of renewable energy sources”, they added. However, at least half its processing capacity will reside in the UK and the cost of any long-distance communication will be factored into the procurement.
The precise configuration is yet to be determined, with the Met Office saying it is “architecture-agnostic” regarding whose components will be used.
The BBC reported that after five years, upgrades are planned in order to boost performance still further.