National Weather Service
The National Weather Service is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration branch of the Department of Commerce, and is headquartered in Silver Spring, Maryland, within the Washington metropolitan area. The agency was known as the United States Weather Bureau from 1891 until it adopted its current name in 1970.
The NWS performs its primary task through a collection of national and regional centers, and 122 local Weather Forecast Offices. As the NWS is an agency of the U.S. federal government, most of its products are in the public domain and available free of charge.
History
1870–1899
Early attempts to record weather information can be traced back to Joseph Henry of the Smithsonian Institution, who, after a tornado in Jefferson, Illinois, in 1855, wrote to the Daily Democratic Press in Chicago for more information about the storm. Organized large-scale weather recording by the Smithsonian led to the creation of the U.S. Signal Service, the earliest predecessor of the modern-day National Weather Service. In 1869, Cleveland Abbe, then director of the Cincinnati Observatory, began developing and issuing public weather forecasts using daily weather observations collected simultaneously and sent via telegraph by a network of observers. This effort was undertaken in cooperation with the Cincinnati Chamber of Commerce and Western Union, which he convinced to back the collection of such information. Meanwhile, Increase A. Lapham of Wisconsin lobbied Congress to create a storm warning service, having witnessed the destructive power of storms in the Great Lakes region. Representative Halbert E. Paine introduced a bill authorizing the secretary of war to establish such a service. On February 9, 1870, the first official weather service of the United States was established through a joint resolution of Congress signed by President Ulysses S. Grant with a 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 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 as Congress felt "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 Service under the chief signal officer, Brigadier General Albert J. Myer. Myer gave the National Weather Service its first name: The Division of Telegrams and Reports for the Benefit of Commerce.In November 1870, Myer hired Lapham as the first civilian assistant to the new service, but Lapham left less than two years later. Abbe joined as the second civilian assistant to Myer in January 1871 and began developing a system for national forecasts, based on his work in Cincinnati, which he began issuing the following month. Throughout his career with the weather service, which lasted 45 years, Abbe urged continued research in meteorology to provide a scientific basis for forecasting. While a debate went on between the Signal Service and Congress over whether the forecasting of weather conditions should be handled by civilian agencies or the Signal Service's existing forecast office, a Congressional committee was formed to oversee the matter, recommending that the office's operations be transferred to the Department of War following a two-year investigation.
The agency first became a civilian enterprise in 1891, when it became part of the Department of Agriculture and its name officially became the U.S. Weather Bureau. Under the oversight of that branch, the Bureau began issuing flood warnings and fire weather forecasts, and issued the first daily national surface weather maps; it also established a network to distribute warnings for tropical cyclones as well as a data exchange service that relayed European weather analysis to the Bureau and vice versa.
20th century
The first Weather Bureau radiosonde was launched in Massachusetts in 1937, which prompted a switch from routine aircraft observation to radiosondes within two years. The Bureau prohibited the word "tornado" from being used in any of its weather products out of concern for inciting panic until 1938, when it began disseminating tornado warnings exclusively to emergency management personnel.The Bureau would in 1940 be moved to the Department of Commerce. In 1941, Margaret Smagorinsky was hired as the Weather Bureau's first female statistician. On July 12, 1950, Bureau chief Francis W. Reichelderfer officially lifted the agency's ban on public tornado alerts in a Circular Letter, noting to all first order stations that "Weather Bureau employees should avoid statements that can be interpreted as a negation of the Bureau's willingness or ability to make tornado forecasts", and that a "good probability of verification" exist when issuing such forecasts due to the difficulty in accurately predicting tornadic activity. After facing criticism for continuing to refuse to provide public tornado warnings and preventing the release of the USAF Severe Weather Warning Center's tornado forecasts beyond military personnel, the Bureau issued its first experimental public tornado forecasts in March 1952. In 1957, the Bureau began using radars for short-term forecasting of local storms and hydrological events, using modified versions of those used by Navy aircraft to create the WSR-57, with a network of WSR systems being deployed nationwide through the early 1960s; some of the radars were upgraded to WSR-74 models beginning in 1974.
In August 1966, the Weather Bureau became part of the Environmental Science Services Administration when that agency was formed. The Environmental Science Services Administration was renamed the National Oceanic and Atmospheric Administration on October 1, 1970, with the enactment of the National Environmental Policy Act. At this time, the Weather Bureau became the National Weather Service.
At the beginning of the 1980s the NWS used the same radar equipment as in the 1950s, and teletype for communication. In 1983, NOAA administrator John V. Byrne proposed to auction off all of the weather satellites, to repurchase data from private buyers, outsourcing weather observation stations, NOAA Weather Radio and computerized surface analysis to private companies but the proposal failed in a Congressional vote.
NEXRAD, a system of Doppler radars deployed to improve the detection and warning time of severe local storms, replaced the WSR-57 and WSR-74 systems between 1988 and 1997.
21st century
In 2025, the National Weather Service was deeply affected by cuts to NOAA under the second presidency of Donald Trump, including staff being laid off, contracts with universities being cancelled, and restrictions on exchanges with other national weather services. Entering hurricane season, 30 National Weather Service offices were without a chief meteorologist, in part due to Trump administration layoffs.On August 28, 2025, President Trump signed an executive order, which dissolved the NWS Employee Union, and determined the National Weather Service "to have as a primary function intelligence, counterintelligence, investigative, or national security work". The White House justified this decision by stating that the National Weather Service provides "weather and climate data that inform the weather forecasting used to plan U.S. military deployments. Weather forecasts have long been critical factor in the success or failure of military operations."
Forecast sub-organizations
The NWS, through a variety of sub-organizations, issues different forecasts to users, including the general public. Although, throughout history, text forecasts have been the means of product dissemination, the NWS has been using more forecast products of a digital, gridded, image or other modern format. Each of the 122 Weather Forecast Offices send their graphical forecasts to a national server to be compiled in the National Digital Forecast Database. The NDFD is a collection of common weather observations used by organizations and the public, including precipitation amount, temperature, and cloud cover among other parameters. In addition to viewing gridded weather data via the internet, users can download and use the individual grids using a GRIB2 decoder, which can output data as shapefiles, netCDF, GrADS, float files, and comma-separated value files. Specific points in the digital database can be accessed using an XML SOAP service.Fire weather
The National Weather Service issues many products relating to wildfires daily. For example, a Fire Weather Forecast, which have a forecast period covering up to seven days, is issued by local WFOs daily, with updates as needed. The forecasts contain weather information relevant to fire control and smoke management for the next 12 to 48 hours, such as wind direction and speed, and precipitation. The appropriate crews use this information to plan for staffing and equipment levels, the ability to conduct scheduled controlled burns, and assess the daily fire danger. Once per day, NWS meteorologists issue a coded fire weather forecast for specific United States Forest Service observation sites that are then input into the National Fire Danger Rating System. This computer model outputs the daily fire danger that is then conveyed to the public in one of five ratings: low, moderate, high, very high, or extreme.The local Weather Forecast Offices of the NWS also, under a prescribed set of criteria, issue Fire Weather Watches and Red Flag Warnings as needed, in addition to issuing the daily fire weather forecasts for the local service area. These products alert the public and other agencies to conditions which create the potential for extreme fires. On the national level, the NWS Storm Prediction Center issues fire weather analyses for days one and two of the forecast period that provide supportive information to the local WFO forecasts regarding particular critical elements of fire weather conditions. These include large-scale areas that may experience critical fire weather conditions including the occurrence of "dry thunderstorms", which usually occur in the western U.S., and are not accompanied by any rain due to it evaporating before reaching the surface.
Image:NWS-IMET-deployed.jpg|right|150px|thumb|NWS IMET Chris Gibson taking observations in the field
State and federal forestry officials sometimes request a forecast from a WFO for a specific location called a "spot forecast", which are used to determine whether it will be safe to ignite a prescribed burn and how to situate crews during the controlling phase. Officials send in a request, usually during the early morning, containing the position coordinates of the proposed burn, the ignition time, and other pertinent information. The WFO composes a short-term fire weather forecast for the location and sends it back to the officials, usually within an hour of receiving the request.
The NWS assists officials at the scene of large wildfires or other disasters, including HAZMAT incidents, by providing on-site support through Incident Meteorologists. IMETs are NWS forecasters specially trained to work with Incident Management Teams during severe wildfire outbreaks or other disasters requiring on-site weather support. IMETs travel quickly to the incident site and then assemble a mobile weather center capable of providing continuous meteorological support for the duration of the incident. The kit includes a cell phone, a laptop computer, and communications equipment, used for gathering and displaying weather data such as satellite imagery or numerical forecast model output. Remote weather stations are also used to gather specific data for the point of interest, and often receive direct support from the local WFO during such crises. IMETs, approximately 70 to 80 of which are employed nationally, can be deployed anywhere a disaster strikes and must be capable of working long hours for weeks at a time in remote locations under rough conditions.