Understating the weather has always been important to us. It has an impact on harvests around the world, our ability to travel and, in years gone by, whether or not a battle could take place. That’s why, throughout history, mankind has always been fascinated with the idea of being able to predict the weather.
Modern weather maps and numerical weather forecasting models are extremely sophisticated, but the very first forms of serious weather forecasting began when early civilizations began to track the passing of the seasons and the weather that came with them. By 300 BC, using astronomical observations, Chinese astronomers had divided a year into 24 periods, which were marked by festivals, each of which had their own weather predication associated with them.
Sometime around 340 BC, the Greek philosopher Aristotle made what is thought to have been the first scientific attempt to predict weather when he published his work called Meteorologica, in which explained his theories on how the rain, lightning and clouds were formed and how that all linked into geography, chemistry and astronomy. Although this very early work on weather forecasting contained many errors, Meteorologica was remarkably astute for its time and it was used as the basis for weather map production for the next 2,000 years.
Today, global weather maps and local weather maps are produced using complex mathematical models that use data gathered from weather satellites, radar, and other weather monitoring equipment, but as long ago as the 15th century, it was recognised that to be able to produce forecast maps, we would need to monitor the current weather conditions. The earliest weather monitoring instruments were the hygrometer, which was invented by Nicholas Cusa to measure humidity. Then, in the mid fifteenth century Galileo Galilei invented the thermometer to measure temperature and it wasn’t until around 1592 that Evangelista Torricelli invented the barometer to measure atmospheric air pressure.
Throughout the seventeenth, eighteenth and nineteenth centuries, weather monitoring instruments were refined and our knowledge of the atmosphere and the weather grew, which lead to the very earliest attempts at producing accurate weather maps. The big leap forward came in the mid-nineteenth century with the invention of the telegraph. Suddenly, weather readings from around the globe could be shared and compared, which led to the production of the very first crude global weather maps. By the late 1860s weather stations had appeared all across the globe and weather maps for Africa, weather maps for Europe, and local weather maps all became possible.
The next great leap forward in weather forecasting was the invention of the radiosonde, which was a lightweight box equipped with instruments for reading air pressure, humidity, and temperature, along with a radio transmitter. The box could be sent high into the atmosphere with the of a weather balloon and send weather readings back to the ground.
Today, although the data collection methods are far more sophisticated and the calculations vastly more complex, the theory behind the production of modern synoptic weather maps and weather forecast maps is much the same as it has always been. Through observation and recording of current and past weather conditions we can forecast future weather conditions and that’s how we are able to produce weather forecast maps.