Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting. Meteorological phenomena are observable weather events which illuminate and are explained by the science of meteorology. It is a study that dates back to ancient times, when ancient civilizations made observations and kept records of weather conditions, both for agricultural purposes and out of a general curiosity about the world around them. Over the centuries, the atmosphere has been studied for a variety of reasons, including agricultural knowledge, military defense and planning, and developing better warnings for severe weather systems like tornadoes and hurricanes. Technological advances, such as the development of scientific computing and an increase in the total number of meteorological observations being taken daily across the globe, have allowed for better forecasts (or at least the meteorological community likes to think they are better forecasts) and a much better overall understanding of our atmosphere. Meteorological phenomena are observable weather events that are explained by the science of meteorology. Meteorological phenomena are described and quantified by the variables of Earth’s atmosphere: temperature, air pressure, water vapor, mass flow, and the variations and interactions of those variables, and how they change over time. Different spatial scales are used to describe and predict weather on local, regional, and global levels. There are many specialized branches, or subfields, of meteorology, each defined by both the spatial scale of the phenomena they study and by the other branches of science they involve. In terms of spatial scale, all meteorological study is conducted on either the micro-, meso-, synoptic, or global scale. Microscale meteorology deals with any problems that are on the order of 1 kilometer in size or smaller, things like individual clouds or heat transfers. Mesoscale meterology includes phenomena in the size range from the upper end of the microscale to several hundred kilometers. Lake effect snowstorms, severe thunderstorms, and mesoscale convective complexes.