The word meteorology was first mentioned in the book Meteorologica by the Greek philosopher Aristotle around 340 BCE. The book tried to answer the questions of where different weather phenomena came from and how they could be predicted. The scientific field of meteorology emerged in the 17th century, after various inventions that could be used to measure weather conditions, such as thermometers, barometers and anemometers, were developed.

Although nowadays most meteorological measurements and predictions are made by weather satellites and computers, observations are still important when making predictions about the future weather. Short-term predictions about the weather can be made by observing the current weather conditions. These observations are made from weather stations as well as with weather radars.

After a prediction about the weather has been made, a meteorologist will evaluate the prediction and decide whether or not it is reliable. By entering new observations and data to their specialized meteorological software, the meteorologist can develop the prediction and make it more accurate as time passes and the weather conditions change. 

Typically, the shorter the time span a prediction covers, the more reliable the prediction will be. This is why meteorological predictions are made for 5 days at the most. On longer time spans, the predictions will quickly become unreliable. 

Weather predictions:

• Finnish Meteorological Institute
• Foreca