Japan Plans 30-Year Supercomputer Forecasts

BaltikaTroika writes "According to a ministry representative, 'Japan is planning ultra long-range 30-year weather forecasts that will predict typhoons, storms, blizzards, droughts and other inclement weather.' Maybe they should tell their secret to my local weatherman, who usually can't even get tomorrow's weather right. Whatever happened to chaos?"

RTFA, submitter

[Anonymous Coward]

The results will help establish predictable routes for typhoons and identify areas that are recurring targets for heavy rains, abundant snow, high waves, heavy winds, scorching heat or crop-threatening droughts.

They're not trying to forecast weather 30 years in the future, they're just looking for statistical trends in locations where hurricanes and such are more likely to occur, based on predictions of the overall global climate. Things like "there are probably going to be 20-40% more typhoons off the east coast of Japan in 10 years", not "watch out, Tokyo is going to be hit by a tsunami on August 12, 2032".

Re:Already exists!

[Cycloid Torus]

Not only that, it is available as a download!

http://www.farmersalmanac.com/weather/weather.html [farmersalmanac.com]

Local weatherman accuracy

[LordKazan]

check the accuracy of the national weather service forecasts - they tend to be highly accurate (temperature +-5 degrees F, other conditions very high accuracy)

accuracy tends to extend very well out to the 3-day period and acceptably well to the 7-day

Re:Actually Useful

[Ignignot]

If you are referring to forecasts in the United States, there are several different forecasts provided by the government which provide the baseline to basically everything you see on TV or hear on the radio or whatever. There is a short term forecast called the AVN/NAV which is intended to aircraft, so they will know how to schedule flights. This has a forecast which provides information on 3 hour intervals and is updated many times a day. Next there is the MRF, which goes out 12 days or so (it has been a few years since I looked at it directly) and is a daily forecast, updated several times a day. It is intended for general use and is basically what you see every day. There are some commercial vendors that put their own spin on things, and plenty of specialized forecasts for things like hurricanes, etc. However, these two are the most important forecasts for anyone in the United States, and have been around since the 90's at least. What you may be seeing is a "keeping up with the Joneses" approach to TV weather forecasting. If one station has 9 days, and the other has 8, which one are you going to watch? While that last day may have no accuracy whatsoever, people would still tend to watch one over the other I think.

A Few Things

[Hoplite3]

1) The computer will be doing CLIMATE modeling, not weather prediction. That's a different bird. It's like the difference between the average score on a test and your score on the test. Or like describing the flow of heat, but not knowing the underlying collisions that result in the transfer of energy.

2) Higher precision does help you model chaotic systems longer, but... If you run your model until the difference between your prediction and the actual system is larger than a tolerance, the time when this happens is called the horizon time. If you improve your accuracy (let's say your computer system is perfect and errors only occur in getting the initial state right), you only improve the horizon time as the LOG of your improvement. In an age where quadratic methods are just adequate in scientific computing, this is unbearable.

3) Another weather (not climate) prediction option is to use a statistical cohort model. Such a model just takes in data and tries to predict what will happen next based on past trends. It doesn't know any physics, and can take a while to train. This means that the cohort you train in London is useless in Paris. Such "models" often beat physical models in predictive ability, but don't give any insight into why. If you want to fly a plane, they're fine. If you want to do science, see (1) or (2).

Also, this computer is way, way cooler than the one predicting nuclear bomb blasts. But that's, just like, my opinion, man.

Governmental "Chaos"

[Diamond Tree]

OTOH, this sounds to me, like the very predictable scenario of "the uncuttable budget". Having lived in Japan for 3 years I learned that government budgets, once granted, are inviolable for *eternity*. Why do you think they still do MagLev research in spite of every one else in the world having long since abandoned it? The budget for MagLev research is uncuttable. Until that money can be absorbed by another department in some face-saving way, MagLev research will continue.

Probably there's a budget item somewhere that planned for a certain amount of money to be spent on computer-based weather prediction. This budget is now uncuttable. Any bureaucrat who does not spend their full budget is toast - he (most likely it's a 'he') will never be allowed into a position of budgetary authority again.

If you go to the Ministry of Finance without having spent all your budget you run the significant risk of having it cut the next year. This is a "career-limiting move." Since bureaucrats cannot, at least as a practical matter, be fired by the Prime Minister (remember Reagan firing all the air traffic controllers?) these budgets exist for all time.

*Climatological* research

[Toon Moene]

> The results will help establish predictable routes for typhoons and identify areas
> that are recurring targets for heavy rains, abundant snow, high waves, heavy winds,
> scorching heat or crop-threatening droughts.

In other words: What are probable areas where these phenomena occur and what are the most probable paths for those phenomena that are moving.

The reason they take a 30 year period is not that they want to predict the weather 30 years in advance (that's ridiculous), but that they want realistic weather patterns over a 30 year period to match the standard World Meteorological Organization's 30 year period for defining "climate".

E.g., the current "climate" knowledge of the WMO is (the average of) what happened between 1971 and 2000.

Hope this helps,