The weather forecast story

If you thought that the weather forecast was made entirely by one person in a TV studio, then think again...

It's 3 a.m. and -23 °C on the island of Novaya Zemlya, frozen into the Arctic Ocean. Alexei releases a 4 ft weather balloon (one of 900 being released at that exact moment from every continent on Earth). Alexei watches — as he does every night — as it rises into the starry sky, taking measurements of the atmosphere. From 36,000 km above his head, Earth looks about the size of a football when held at arms length. A satellite the size of a minibus scans the globe, part of constellations which together monitor every cloud in the sky.

Meanwhile the Thomas family have just taken off from Heathrow airport on their way on holiday to Florida, unaware that a sensor on the airliner's nose is relaying meteorological information to weather centres all over the world. On their way over the Atlantic Ocean they pass over a small buoy which has just surfaced after drifting with the deep ocean currents for 10 days.

This multitude of information, and more than half a million more, are channelled into a 20-ton supercomputer, at the Met Office headquarters in Exeter, which runs software composed of more than a million lines of code, written by a team of several hundred professional research scientists. Performing trillions of calculations every second, the computer simulates the future evolution of the atmosphere across the whole planet for the coming hours, days, weeks and months.

90 minutes later, a team of skilled forecasters in the Met Office operations centre are carefully monitoring the computer output. They notice that a storm, which does not yet exist, will form and could cause widespread disruption across much of the UK in four days time. This information is passed on to the television weather presenters who inform the nation and Cabinet ministers are briefed. The financial markets react to the likely change in demand for natural gas as the storm takes hold and emergency responders prepare.

All told, weather forecasting is a global undertaking involving thousands of people, 24 hours a day, across the planet. The result is nothing short of remarkable — we can foresee the future, allowing lives to be saved and paving the way for a more efficient and smoothly running national infrastructure and economy.