UK weather forecasts become ‘more accurate' after Met Office upgrade

Independent

20-05-2025

The Met Office has upgraded to a new supercomputer, which could make 14-day forecasts nearly as accurate as seven-day forecasts.
Forecasters hope the supercomputer, operated by Microsoft's cloud-based system called Azure, will predict extreme weather events further in advance and help to advance climate research across the world.
For more than a month, Azure was running off-site simultaneously with the Met Office 's previous supercomputer, which has now been switched off.
Charles Ewen, the Met Office's chief information officer, said: 'People ask how a bigger computer improves the weather forecast.
'One big thing this new computer will allow us to do in the near future is to be able to produce 14-day forecasts with a similar kind of accuracy than we can today for seven, eight, nine days.'
The weather agency used its first supercomputer 60 years ago, and until now, they have almost always been run on site.
Azure will allow the Met Office to start fresh projects without having to build new infrastructure, he added.
He said: 'We use a technique to predict the future state of the atmosphere called numerical weather prediction.
'So that takes the laws of physics that are fairly well understood and applies them at scale to observations of the current state of the atmosphere.
'To do that is very, very computationally expensive. It's simulating the future state of the atmosphere. Operationally, that's 200 to 300 terabytes of information a day.'
Segolene Berthou, who leads a team of researchers working on the Met Office's environmental prediction capabilities, said the supercomputer will permit researchers to run a model several times with slightly different parameters.
'That will give us quite a large variety of forecasts because of the chaotic nature of the atmosphere, and that can help us capture the extremes with more days in advance,' she explained.
'The coupled system we're preparing is running faster and more smoothly on the new supercomputer.
'This is very good news because it means we can now be even more confident in our climate projections and have longer slices of time running this model.'
A cloud system will make it easier for others to use the Met Office's backlog of data for climate research, the weather service said.
Forecasters are also hoping Azure will allow them to adapt its use of artificial intelligence, however, they are not yet sure how the supercomputer will be augmented with machine learning.
The Met Office has funded some of its researchers to start advanced degrees in machine learning and has offered a training programme on the subject.
Simon Vosper, its science director, said: 'We have huge increases in capacity, which will enable us to take our science forward.
'With the new Azure-based capability, we'll be enhancing resolution, running many more models and introducing new scientific complexity.'
The weather agency said: 'Met Office forecasts are used in aviation, defence, critical infrastructure, and shipping, as well as for predicting storms, floods, and gauging if Sunday will be suitable for a barbecue.
'The decision to entrust that critical work to an outside institution like Microsoft came only after a long process, informed by its own expertise in technology.'