We all want to know what the weather is going to be like. It helps us to plan out our days. We want to know how warm to dress, if we should bring an umbrella, or if it will be a good day for a picnic. Although it may sometimes seem like weather forecasters are just guessing, there is a lot of science that goes into predicting the weather. Meteorology Meteorology is the study of the Earth's atmosphere. Scientists who study the atmosphere are called meteorologists. By studying the Earth's atmosphere, meteorologists are able to predict what the weather will be. However, there are a lot of variables that goes into predicting the weather. For this reason, the predictions are not 100% accurate. Meteorologists measure and study many aspects of the Earth's atmosphere. In order to forecast the weather, they study high and low pressure systems and the boundaries between them called weather fronts. We describe these in more detail below. Highs and Lows Knowing areas of high and low air pressure is important to predicting the weather because differences in air pressure causes wind to form. High pressure system - A high pressure system generally means good weather because it attracts cool and dry air. On a weather map a high pressure system is shown by a blue H.