Weather Theory and Reports Chapter4 Introduction Weather is the state of the atmosphere at a given time  and place, with respect to temperature, moisture content,  turbulence, and cloudiness. These factors interact to form  the following five major meteorological elements: A solid understanding of weather theory provides the tools  necessary to understand the reports and forecasts obtained  from a Flight Service Station (FSS) weather specialist and  other aviation weather services. No other means of aviation  relies more heavily on knowledge and understanding of  weather for its safety than ballooning. It is important to note,  however, that there is no substitute for experience. •  Atmospheric pressure (high or low), •  Air temperature (heat or cold), •  Wind (calm or storm), •  Clouds (clearness or cloudiness), and •  Precipitation (rain, sleet, snow). 4-1