History of Surface Weather Analysis - Nineteenth Century

Nineteenth Century

The use of weather charts in a modern sense began in the middle portion of the 19th century. Weather map pioneers include William Charles Redfield, William Reid, Elias Loomis, and Sir Francis Galton, who created the first weather maps in order to devise a theory on storm systems. The invention of the telegraph in 1837 made it possible to gather weather information from multiple distant locations quickly enough to preserve its value for real-time applications. The Smithsonian Institution developed its network of observers over much of the central and eastern United States between the 1840s and 1860s once Joseph Henry took the helm. Beginning in 1849, the Smithsonian started producing surface analyses on a daily basis using the 150 stations in their network. The U.S. Army Signal Corps inherited this network between 1870 and 1874 by an act of Congress, and expanded it to the west coast soon afterwards. Three times daily, all stations would telegraph in their observations to the central office which would then plot the information on a map upon which isobars, or lines of equal pressure, would be drawn which would identify centers of high and low pressure, as well as squall lines. At first, all the data on the map was not taken at exactly the same time in the early days of these analyses because of a lack of time standardization. The first attempts at time standardization took hold in the Great Britain by 1855. However, in the United States, standard time did not come to pass until 1883, when time zones started to come into use across America for railroad use. The entire United States did not finally come under the influence of time zones until 1905, when Detroit finally established standard time.

The earliest surface analyses from the United States featured a map of the continental U.S. with indications of cloud cover and wind direction arranged on an early form of what has become a station model. A general indication of the weather for various cities around the country was also included on the bottom of the map. Within a short time, the Signal Corps added a tables showing eight-hour pressure change, 24-hour temperature change, relative humidity, and 24-hour precipitation. The Signal Office also added a general discussion of synoptic weather features and forecast, before adding isobars and isotherms onto the maps. By the end of 1872, the maps had established the format it would use until the introduction of frontal analysis. By the 20th century, most of the weather-related functions under the U. S. Signal Corps branched off into a new civilian agency known as the U. S. Weather Bureau, the forerunner of today's National Weather Service.

Internationally, other countries followed the lead of the United States, in regards to taking simultaneous weather observations, starting in 1873. Other countries then began preparing surface analyses. In Australia, the first weather map showed up in print media in 1877. Japan's Tokyo Meteorological Observatory, the forerunner of the Japan Meteorological Agency, began constructing surface weather maps in 1883.