It has high hopes that the new machines will halve the number of "busts"--when forecasters fail to warn about a storm, or forecast a wet weekend that turns out to be sunny.
The two NEC SX-6s are six times the speed of the two Cray T3E machines that they replace. The NEC machines possess processing power of just less than a teraflop, or a trillion calculations per second, with 927.6 million instructions per second (mips) achieved and a theoretical maximum of 960mips.
"Until last Friday, the two machines were run in parallel for a while," a Met Office representative said. "Then the Cray machines were turned off. Next year, the NEC installation will be upgraded to over a teraflop."
The weather forecasters expect the new machines to improve forecasting accuracy by about 6 percent and thus improve its service to customers.
Besides the general public, the Met Office has a large number of business clients, from supermarkets that want to know how much ice cream to stock in hot weather to utilities needing to anticipate high demand for electricity in extremely hot or cold weather.
The new Met computers may be powerful, but they stand only 275th and 276th in the world rankings of supercomputers released Monday. In the United Kingdom, the Reading-based European Centre for Medium-Range Forecasts (ECMWE) has three machines that are more powerful. Its fastest--rated sixth in the world--is an IBM eServer pSeries 690 with a theoretical speed of 16 teraflops.
The Met Office's own statistics show that its three-day forecasts are now as good as its one-day forecasts were in 1980. The Met Office representative said: "Since (a major misforecast) storm in 1987, there's been a lot more equipment put out there in the ocean. And obviously, with satellites, we can look at how the weather is behaving."
The representative confirmed that the Met Office computers take data from the more powerful machines at the ECMWE center.
Ron Coates of Silicon.com reported from London.