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A British Supercomputer Can Predict Winter Weather a Year In Advance (thestack.com)

Posted by EditorDavid on from the seeing-the-future dept.

The national weather service of the U.K. claims it can now predict the weather up to a year in advance. An anonymous reader quotes The Stack: The development has been made possible thanks to supercomputer technology granted by the UK Government in 2014. The £97 million high-performance computing facility has allowed researchers to increase the resolution of climate models and to test the retrospective skill of forecasts over a 35-year period starting from 1980... The forecasters claim that new supercomputer-powered techniques have helped them develop a system to accurately predict North Atlantic Oscillation -- the climatic phenomenon which heavily impacts winters in the U.K.
The researchers apparently tested their supercomputer on 36 years worth of data, and reported proudly that they could predict winter weather a year in advance -- with 62% accuracy.

2 of 177 comments (clear)

  1. Really ? by ctrl-alt-canc · · Score: 3, Informative

    Arnold in one of his textbooxs demonstrated that, to make a weather prediction one month in advance, you need to measure pressure, temperature, wind speed and humidity with at least five significative decimals. He used sound mathematical methods based upon a theorem by Poincaré. With all the respect for technical skills and competence of people at Met Office, I trust more what Arnold demonstrated using nothing but paper and pencil. Good math is never overcome by brute force computation.

    1. Re:Really ? by ctrl-alt-canc · · Score: 3, Informative

      When quoting Arnold I have been a little incorrect, since five figures of precision in the measurement of physical variables actually give you a two months forecast. But I studied this about thirty years ago...
      If you want to estimate the error, if n is the number of months of the forecast and eps is the measurement precision, the error is given by:
      10^(2.5n) times epsilon. As you can see the error rapidly increases, although the formula I transcribed from Arnold's textbook is quite rough (toroidal Earth, steady flux and negligible viscosity). Not a bad approximation for estimating trade winds flux, however.
      People at MET probably took care of the propagation of numerical errors in the calculation, by increasing the grid density and maybe setting up a system capable of working with quadruple precision. However the problem again is the needed precision of input data, that increases exponentially with the time forecasted.