The National Weather Service (NWS) is a federal agency that has been in existence since 1870. The "original" NWS began under the direction of the Signal Corps until it was transferred to the Department of Agriculture in 1890. This was part of the "Organic Act" that defines the responsibilities of the agency. The Weather Bureau remained under the Department of Agriculture until 1940 when it was transferred to the Department of Commerce...where it remains today.
The Weather Bureau was renamed the National Weather Service and, in 1970, was placed under the newly created National Oceanic and Atmospheric Administration (NOAA) which remains under the Department of Commerce.
The National Weather Service provides 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. NWS data and products form a national information database and infrastructure which can be used by other governmental agencies, the private sector, the public, and the global community.
This mission is accomplished by providing warnings and forecast of hazardous weather, including thunderstorms, flooding, hurricanes, tornadoes, winter weather, tsunamis, and climate events. The NWS is the sole United States OFFICIAL voice for issuing warnings during life-threatening weather situations. The organization structure of the NWS is as follows:
The President of the United States
Department of Commerce
National Oceanic and Atmospheric Administration (NOAA)
National Weather Service