A weather map (or synoptic chart) is a visual tool that displays meteorological features like pressure, temperature, and wind using specific symbols, and has been essential for research and forecasting since the mid-19th century. These maps come in various forms—such as isobars for pressure systems, isotherms for temperature gradients, and isotachs for locating the jet stream—each providing unique insights into atmospheric conditions. The modern weather map was born in the 19th century after the Crimean War, when Urbain Le Verrier proved a storm could have been predicted, leading Francis Galton to create the world's first weather map in 1861 and coin the term "anticyclone." The development of these maps relied heavily on the invention of the telegraph (first used for weather in 1847) and the standardization of time, such as the adoption of Greenwich Mean Time, to ensure data was synchronized. In the United States, the Smithsonian Institution and later the U.S. Army Signal Corps built a national observer network, though full time-zone standardization wasn't achieved until 1905. In the 20th century, the field advanced significantly with the Norwegian polar front theory, developed by Jacob Bjerknes during World War I, which introduced the concept of weather fronts to these charts.