A "super computer" is being installed at the Met Office's new home in Devon.
The "super computer" will help produce more accurate forecasts
The computer will be able to carry out 1,500 billion calculations per second when it goes live in six weeks' time.
It will form the lynchpin of the Met Office's weather forecasting operation at its new offices in Exeter.
Almost all of the Met Office's 1,100 staff are on course to have moved from Bracknell into the new premises by November.
The computer will be the key to ensuring the weather men give the most accurate forecasts possible.
When it was new, it was the biggest super computer outside of America.
Met Office chief executive Peter Ewins said: "About 180 countries supply data to the Met Office every day about the state of the weather.
Met Office staff are set to have moved in by November
"We can then use what's called a mathematical algorithm to represent the physics and the chemistry of the atmosphere in the super computer.
"By putting in the data which is the known state of the atmosphere today, we can crunch those numbers and predict it for tomorrow, the next day and the day after that."