The Washington D.C.

National Weather Service (NWS), once known as the Weather Bureau, is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration (NOAA) of the United States government. It is headquartered in Silver Spring, Maryland.
The NWS is tasked with providing "weather, hydrologic, and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas, for the protection of life and property and the enhancement of the national economy." This is done through a collection of national and regional centers, and 122 local weather forecast offices (WFOs). Since the NWS is a government agency, most of its products are in the public domain and available free of charge.


In 1870 the Weather Bureau was established through a joint resolution of Congress signed by President Ulysses S. Grant with the mission "to provide for taking meteorological observations at the military stations in the interior of the continent and at other points in the States and Territories...and for giving notice on the northern (Great) Lakes and on the seacoast by magnetic telegraph and marine signals, of the approach and force of storms." The agency was placed under the Secretary of War because "military discipline would probably secure the greatest promptness, regularity, and accuracy in the required observations." Within the Department of War, it was assigned to the U.S. Army Signal Corps under Brigadier General Albert J. Myer. General Myer gave the National Weather Service its first name: The Division of Telegrams and Reports for the Benefit of Commerce.


The NWS issues a comprehensive package of forecast products to support a variety of users, including the general public. Although text forecasts have been the primary means of product dissemination, the NWS has been converting its forecast products to a digital, gridded format. Each of the 122 Weather Forecast Offices (WFOs) send their graphical forecasts to a national server to be compiled in the National Digital Forecast Database (NDFD). This is a collection of sensible weather elements such as: maximum and minimum temperature, humidity, cloud cover, probability of precipitation, amount of precipitation and wintry precipitation, weather type, and wind direction and speed. In addition to viewing gridded weather data via the internet, more advanced users can decode the individual grids using a "GRIB2 decoder" which can output data as shapefiles, netCDF, GrADS, float files, and comma separated variable files. Specific points in the digital database can be accessed using an XML SOAP service. These capabilities have greatly increased the audience of NDFD data. The NWS has received some criticism from commercial weather vendors for providing graphical forecast data free of charge. They argue that such tailored forecast information compete with their own products. However, a large majority of private weather firms quickly realized its potential benefits and have flourished by using the NDFD as a tool for composing their products.