Once upon a time – about a century ago – a man called Lewis Fry-Richardson devised a system for weather forecasting which would require 64,000 people working round the clock making calculations. (And Lewis’s eight-hour forecast, which took six weeks to construct, was wrong, incidentally.) Since then things have changed just a bit…

Nowadays there’s a huge white room in the Met Office that houses its supercomputer, the SX8, produced by the Japanese company NEC. It’s a slightly chilly room, and hums and buzzes loudly. The constant temperature is maintained with 57 cubic metres of cooled air per minute (and the heat exchange helps to keep the rest of the building warm). The IT room is carefully protected from an environmental point of view – it’s dust-free, so plastic covers over your outdoor shoes, please.

And no wonder the Met Office take such care of it. The SX8 was installed at a cost of £27.5 million. At that price there is a pretty small market for such things – the Met Office is one of only two places in Europe to operate one. (And in fact, for the sake of reliable back-up, the Met Office actually has two of them.)

Information overload

This is the Met Office’s heart of operations, where bits of data constantly arriving from all sorts of sources (local volunteer observers, weather balloons, airplanes, satellites) are crunched to simulate the global atmosphere. Results obtained from the machines humming in this room will provide the information for local radio weather broadcasts, but also for climate research for teams investigating global warming, for planners of military deployments in Afghanistan, and in countless other ways.

Now, to look at, you wouldn’t think this machine is all that impressive. It doesn’t look excitingly futuristic, rather disappointingly – it’s just a few clusters of solid-looking towers, each about the size and shape of a drinks vending machine. (And each looking, as it happens, a lot like a drinks vending machine.) But impressive it really is. For one thing, it’s about as powerful as 8,000 home computers. It has a memory of 1280 gigabytes. Its calculations are counted in "floating point operations". At its peak, the SX8 carries out 2,560,000,000,000 of these operations every second. So now you’re impressed, aren’t you?