The BOM guys have told me that the ECMWF models [
European
Centre for
Medium range
Weather
Forecasting ] are about the best of the forecasting models around at the moment.
http://www.yr.no/Enter your location / nearest town etc in the search box; [ You may be given a list of locations to choose from ]
You then have a quick and dirty update in "Long Term".
More detail in "Hour by Hour"
Or the map;
In the "Rest of the World" box, 3 hrs runs only go out to some 48 hours so I deselect 3 hrs and select 6 Hrs for the full run consistency of the maps
The maps will take you out to about 240 hours ;eg; today's run "1st jan 02;00 > 10 jan 1700
The ECMWF only provides precipitation and some other info to the participation national weather Authorities and this info is not normally available to the public.
The Norwegians have a law that what the public pays for through their taxes the public gets to see for no charge hence the ECMWF's precipitation and etc is available on the
http://www.yr.no/You may also find some info in the ECMWF's ;
http://www.ecmwf.int/products/forecasts/d/chartsThe "Seasonal Forecast" can be of some use.
Medium Range Forecasts > Deterministic Forecast > Australia uses a rotating series of forecasts and if you follow it , you will get lucky and get a 240 hr precipitation forecast as the various forecasts are run through over the days.
JMA has one month and three month prediction maps in generalised terms;
http://ds.data.jma.go.jp/tcc/tcc/products/model/The American Navy's Monterey based ; Fleet Numerical Meteorology and Oceanography Center uses the 240 hr NOGAPs model;
http://www.usno.navy.mil/FNMOC/ > WXMAP > Tropical Areas > Oceania > NGP / GFS > 6 hr precipitation rate
Beyond 240 hours or maybe even about 180 hours, the tiniest of incorrect inputs into the models when they start their runs or even a normally very low level and undetectable fault in the computer hardware or software after millions of calculations can lead to huge variations in the final projected forecast.
It is a function of Chaos Theory in the computer where after a huge number of computations the tiniest of changes from either the initial input or even from the lack of accuracy limited by the decimal points used which is how the Chaos Theory was first detected and the theory developed, can start to create large deviations in output runs from and between the same model.
This why the meteorologists are still essential and still need to have the final word as they know from their previous experience and training whether some computer scenarios are just ridiculous or maybe are possible or most likely.
I have been told by Met persons that these arguments can get pretty heated on what modeled forecasts to believe or how they should be modified to get closer to the potential reality of the developing weather situation.
Bigger and faster computers will extend the forecast period by a very short few tens of hours but basically, if we want to see longer but still accurate forecasts the underlying knowledge behind global meteorology must be further researched and increased as faster computers without that better meteorology knowledge merely leads to increases in the speed of making the wrong forecasts.
And a bit on Chaos Theory and why it is the limiting factor in weather [ and climate ] forecasting
Chaos Theory for BeginnersHow Chaos Theory was born and why.
It all started to dawn on people when in 1960 a man named Edward Lorentz created a weather-model on his computer at the Massachusetts Institute of Technology. Lorentz' weather model consisted of an extensive array of complex formulas that kicked numbers around like an old pig skin. Clouds rose and winds blew, heat scourged or cold came creeping up the breeches.
Colleagues and students marveled over the machine because it never seemed to repeat a sequence; it was really quite like the real weather. Some even hoped that Lorentz had built the ultimate weather-predictor and if the input parameters were chosen identical to those of the real weather howling outside the Maclaurin Building, it could mimic earth's atmosphere and be turned into a precise prophet.
But then one day Lorentz decided to cheat a little bit. A while earlier he had let the program run on certain parameters to generate a certain weather pattern and he wanted to take a better look at the outcome. But instead of letting the program run from the initial settings and calculate the outcome, Lorentz decided to start half way down the sequence by inputting the values that the computer had come up with during the earlier run.
The computer that Lorentz was working with calculated the various parameters with an accuracy of six decimals. But the printout gave these numbers with a three decimal accuracy. So in stead of inputting certain numbers (like wind, temperature and stuff like that) as accurate as the computer had them, Lorentz settled for approximations; 5.123456 became 5.123 (for instance). And that puny little inaccuracy appeared to amplify and cause the entire system to swing out of whack.
Exactly how important is all this? Well, in the case of weather systems, it's very important. Weather is the total behavior of all the molecules that make up earth's atmosphere. And in the previous chapters we've established that a tiny particle can not be accurately pin-pointed, due to the Uncertainty Principle! And this is the sole reason why weather forecasts begin to be bogus around a day or two into the future. We can't get an accurate fix on the present situation, just a mere approximation, and so our ideas about the weather are doomed to fall into misalignment in a matter of hours, and completely into the nebulas of fantasy within days. Nature will not let herself be predicted.
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