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How far in advance should I check the weather forecast?

        Science | Storms

Fallible Forecasts and Dependable Patterns
Yes, not even Captain Planet has a good handle on what the weather will bring. Ultimately, all meteorology can do is calculate, speculate and guess.
Yes, not even Captain Planet has a good handle on what the weather will bring. Ultimately, all meteorology can do is calculate, speculate and guess.
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­You can blame your local weather forecast all you want, write angry letters to meteorologists and even take matters into your own hand with a little homespun meteorology. In the end, however, the fault lies not with your local weather anchor, but with the rich complexity behind every breeze, cloud or sprinkle that takes place in Earth's atmosphere.

It's easy to get lost staring at the swirling currents in a Jacuzzi -- and not just if you've been in there for 30 minutes. If left unused and empty, you have nothing but a tub full of hot water. But what happens when you turn on the jets or adjust the thermostat? What happens when, a few margaritas to the wind, you and your friends finally tumble in for a dip?

The Jacuzzi jets churn the waters to life, the rise in temperature creates more steam and the bevy of bodies force new currents in the chlorine-rich water. Various competing and random causes create an entire system of effects. Now imagine a Jacuzzi filled with roughly 5.5-quadrillion-tons (4.99-quadrillion-metric-tons) of gas and stirred to life by such factors as gravity, solar radiation, terrestrial radiation, temperature, pressure, topography and human civilization. You're lounging in Earth's atmosphere, a vast, gaseous body so complicated that even our most powerful computers can't always anticipate it more than a few moves into the future.

The unruly atmosphere, however, does adhere to definite physical laws and follows established patterns, which we call climate. Meteorologists predict the weather by examining past patterns and comparing them to observable atmospheric phenomena to create a model of the future. In this respect, it's like owning a pet. You know how Fido normally behaves given various conditions. As such, you can gauge current or upcoming conditions and make a decent guess as to how he'll behave.

The weather, however, is far more complicated and temperamental.