Weather

Bill Bruce in September 1959 broadcasting from Lime Grove

When George Cowling became the first television weatherman in 1954, he was assisted by a great deal of experience and scientific understanding, some statistically-developed 'rules' and little else.

His main tools were pencils (and a rubber) for analysing the charts plotted by his assistant, and a pair of dividers for measuring isobar spacing to give wind speeds. He worked at the London Weather Centre - then in Kingsway - and had to transport a large bundle of rolled charts across London to the BBC's Lime Grove Studios in Shepherd's Bush.

One of the first technological developments was the receipt of charts via a large fax machine. The modern era arrived for forecasting when the first electronic computer was installed at Met Office headquarters, then in Bracknell, in 1962 and the first operational guidance from this computer increased the accuracy of the forecast.

From faxes to satellites

In 1964 the first operational pictures from satellites became available. But it was not until 1973 that the biggest single increase in accuracy was seen. A new and more powerful computer producing a detailed 10-level numerical model of the Earth's atmosphere doubled the accuracy of the three-day forecast. Information was now arriving regularly from satellites and the forecaster's world was expanding.

Supercomputers

The CDC Cyber 205 was the first Met Office supercomputer and was installed in 1981. This introduced a 15-level atmospheric computer model. Further developments included the installation at Met Office HQ of two Cray Y-MP super computers (one of the world's largest computers) in 1990 and 1991. These allowed the introduction of a new 19-level model and further improved the representation of atmospheric processes.

Both machines were replaced by a single Cray C90 in May 1994 with a six-fold increase in the speed of processing. Then in 1996 a Cray T3E supercomputer was installed, five times more powerful than the Cray C90, followed by a second T3E in 1999.

These huge changes in processing speed and computer power, have continued to improve the accuracy of the weather forecasts. Some measures of accuracy showed an improvement from 79% before 1980 to 86% in 1996.

In 2004 the Met Office introduced its next supercomputer made up of 30 NEC SX-6 nodes running at its new HQ site in Exeter. This provided six times the power of the previous supercomputers.

More recently, in 2008 the Met Office upgraded to the next-generation supercomputer, which achieves even more accurate and detailed short range weather forecasts through high-resolution computer simulations.

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