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A British Supercomputer Can Predict Winter Weather a Year In Advance (thestack.com)
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.
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.
It is predicting climate, not weather.
I'm a good cook. I'm a fantastic eater. - Steven Brust
No, what they mean is they test it by feeding it the data from 1995, then comparing its predictions to what the weather was actually like in 1996. They are doing exactly what you say is the only way to test the validity of the data - they just started collecting data long ago.
THAT SAID, 62% correct doesn't seem all that awesome unless they use very tight margins. Does the computer say it'll be -10C and then count it as a fail if it's actually -11C? -15C? Does it say 'Good enough' if it says "Rain and 5C" and instead we get "Snow and -2C"?
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When asked how he could tell how cold the winters would be, one old chief just said, "I watch how much firewood the white man splits."
That only sounds silly to people who don't consider humans to be animals.
If the chief would have answered that he looked at how much food beavers stockpiled then no-one would have found it funny.
White mans gut feeling works just as well as any other animals gut feeling and is a hell of a lot better than flipping a coin.
It's NOT a statistical model, at least not in the sense you're likely thinking. Although the actual scientific article is ridiculously paywalled, it's definitely a dynamical model that numerically integrates partial differential equations (like the Navier-Stokes equations) forward to produce a solution. They are using an ensemble of the dynamical model solutions to create their forecast. Similar models already exist, such as NOAA's CFS, which are ensembles that make predictions several months in advance. No, you can't predict the weather on a given day months in advance (the limit is believed to be around 21 days) because the atmosphere is a chaotic system and small errors grow too large to make predictions useful. However, certain large scale phenomena such as El Nino have exhibited some predictability well beyond that time frame. Although there is no skill in predicting weather on a single day, statistical quantities like the mean have greater predictability. Using an ensemble, with each member initialized from different initial conditions, means that the predictability can be quantified in spite of the errors in the initial state. If you started the ensemble with 60 members using initial conditions from 60 days and integrated it forward a year, you'd expect to find even chances of the negatice phase and the positive phase of the NAO if there is no predictability. If a significant majority of the solutions show one phase instead of the other, it suggests that there is some predictability of the feature (in this case, the NAO) despite the uncertainty and errors from the initial conditions. The full ensemble is a stochastic model, but that's not statistical in the sense you were probably suggesting.