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.

Comments

No it can't

[Mr D from 63]

I call BS on the headline. Let the damn thing prove it can do it before we claim it can. And doing regression model tweaking doesn't prove anything.

Re:No it can't

[michelcolman]

Hey, but 62% accuracy... that's 12% better than me!

Re:No it can't

[Anonymous Coward]

I call BS on the headline. Let the damn thing prove it can do it before we claim it can. And doing regression model tweaking doesn't prove anything.

Why? Predicting the winter weather in Britain is pretty simple. This little program will get it right about 90% of the time:

#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

int main()
{
char date[32];
time_t rawtime;

time (&rawtime);
struct tm *timeinfo = localtime (&rawtime);
strftime(date, sizeof(date)-1, "%d.%m.%y_%H:%M:%S", timeinfo);

printf("[%s] Weather prediction: Precipitation\n", date);
sleep(86400);
}

So can I

[blogagog]

66% of the days in London contain some form of precipitation. So, I predict rain every day. I'm right 66% of the time. Wow, I'm smarter than a supercomputer!

Re:fallacy

[Calydor]

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"?

Re:fallacy

[phantomfive]

No, not at all, because doing what you described is incorporating brand new data every year.

They kept adjusting the algorithm over and over until they got the right answer from 1980 onwards. The huge risk with that method is overfitting, and if you develop an algorithm this way, it's important to also show that you've managed to avoid overfitting.

You can do the same thing with stock market data: adjust it until you get nearly 90% correct returns on a test interval, then you will find that the next year, the model is completely wrong because of overfit. Even if you incorporate the next years data, you will still get incorrect results because the nature of the stock market is chaotic and also random.

Re: fallacy

[Anonymous Coward]

And more ignorant nonsense gets modded Informative. The anti-science here is getting worse. Posters like you not only drastically overestimate your own knowledge of unfamiliar fields, you then insist to others it must all be a scam.

Weather and climate models aren't some arbitrary curve-fitting; they're physically based using ridiculously detailed physical simulations of air movements and ocean currents, starting from an observed state and running the simulation forward. Read up a little, and maybe you'll learn how to learn again.