A map of U.S. National Weather Service offices as of 2025

Congress passed a resolution on February 9, 1870, directing the Secretary of War to create a service to report weather observations and provide storm warnings for the Great Lakes and Atlantic coastline. This responsibility fell to the U.S. Army's Signal Service.

Twenty years later, on October 1, 1890, Congress spun off those duties into a dedicated agency known as the U.S. Weather Bureau, created under the Department of Agriculture. The newly formed agency quickly took on the responsibility of issuing flood warnings for the Mississippi, Savannah, and Potomac Rivers.

The first decades of the U.S. Weather Bureau's existence saw tremendous advances in both society and technology.

The government began using airplanes for upper-air research in 1904. Free-rising balloons were first used to collect atmospheric observations in 1909. The 1910s and 1920s saw a heavy focus on developing observation and reporting networks for aviation. Officials implemented a dedicated hurricane warning service in 1935—the same year automated weather stations were first deployed on buoys to relay observations from open waters.

The U.S. Weather Bureau transferred to the Department of Commerce in 1940. Air Force meteorologists Ernest J. Fawbush and Robert C. Miller issued the first successful tornado forecast in 1948. Tornado forecasts, which had been officially banned for decades to prevent panic, were officially authorized for public consumption in 1950.

Swift advances in technology allowed the science of meteorology to flourish through the 1950s and 1960s, a period that saw the Bureau establish the National Severe Storms Center (1961) and the National Severe Storms Laboratory (1964).

Congress passed the National Environmental Policy Act, which renamed the agency the National Weather Service on October 1, 1970.

Before 1992, the National Weather Service consisted of many local offices spread across the United States, often located in major cities and at airports, providing forecasts, observations, and warnings for the surrounding areas. For example, North Carolina had Weather Bureau Offices in Asheville, Cape Hatteras, Charlotte, Greensboro, Raleigh, and Wilmington as recently as the early 1990s.

Congress passed the Weather Service Modernization Act of 1992 to consolidate these offices and ensure the agency had resources to keep up with evolving technology. Today, the National Weather Service operates 122 Weather Forecast Offices (WFOs) throughout the United States and its territories. These offices are staffed 24/7/365 to produce forecasts, severe weather alerts, and decision support for their areas of responsibility.

A WSR-57 radar scope tracking Hurricane Donna in southern Florida in 1960.

Weather radar works by sending out a beam of microwave energy into the atmosphere. These microwaves bounce off objects in the air—raindrops, hailstones, snowflakes, even larger objects like tornado debris and flocks of birds—and a tiny bit of that energy reflects back to the radar dish.

The time it takes for the energy to return to the dish allows the computer to determine where the precipitation is located, and the intensity of the returning energy tells us the intensity of the precipitation.

Originally developed for military use to scan the skies for enemy aircraft, troops discovered that their radars were detecting precipitation instead.

The U.S. Navy transferred 25 decommissioned aircraft radar dishes to the U.S. Weather Bureau in 1942, kicking off the use of radar for meteorological use.

A map of WSR-57 and WSR-74 sites across the United States before modernization in the 1990s.

Meteorologists worked through the 1940s and 1950s to develop and design dedicated weather radars.

The first generation of weather radar was dubbed Weather Service Radar-1957 (WSR-57), and the first dish was commissioned in Miami on June 26, 1959.

WSR-57 was only capable of detecting the location and intensity of precipitation. The returns had a coarse resolution, and there was no way for forecasters to determine wind speeds within a storm.

Dozens of these sites were installed across the country—mostly east of the Rockies—through the 1960s and 1970s. Forecasters developed an updated radar, dubbed WSR-74, which were installed as "gap fillers" over the next couple of decades.

A map of the NEXRAD network's coverage across the U.S., its territories, and South Korea.

The late 1980s brought about a tremendous leap in radar technology. Utilizing the Doppler effect, weather radar could now judge the velocity of the objects being detected. In other words, this advance enabled us to see wind speeds and wind direction. The new network of WSR-88D Doppler radars were collectively called NEXRAD, short for Next-Generation Radar.

Doppler weather radar has saved countless lives since the first site was installed in northern Virginia in June 1992. Monitoring the speed and direction of winds within a thunderstorm allows forecasters to issue warnings for tornadoes and severe thunderstorms, often with ample lead time.

A radar image of a tornadic supercell thunderstorm over Tuscaloosa, Alabama, on April 27, 2011.

In addition to Doppler capability, WSR-88D has a leg up on previous iterations of weather radar with increased range of coverage, vastly superior resolution, and the ability to rapidly scan multiple elevations to give forecasters a full view of a storm.

WSR-88D sites were upgraded in the 2010s with dual-polarization technology. The dishes now send out two beams of microwave energy instead of just one. This enables the dish to determine the size and shape of the objects being detected. This is especially helpful in spotting tornado debris lofted into the air, a signal forecasters can use to provide urgent warning to those in harm's way.

The first weather satellites launched in the 1960s and early 1970s only provided brief glimpses of Earth's surface as they passed overhead. Today, daily weather satellite imagery almost always comes from satellites parked in geostationary orbit.

These vehicles orbit at 22,236 mi above the Earth's equator—a precise altitude that places the satellite's orbiting speed at the exact same rate the planet rotates on its axis. A geostationary orbit allows the satellite to remain 'fixed' over one precise point on Earth's surface, providing its instruments the same exact view of Earth for long periods of time.

The United States' premier network of weather satellites is called GOES—short for Geostationary Operational Environmental Satellites. The GOES program began in 1975 with the launch of GOES-1, and continues today with the most recent launch of GOES-19.

A comparison in full-disk satellite images between GOES-1 in 1975 and GOES-19 in 2025.

We've benefitted from five families of GOES satellites since the beginning of the program.

GOES 1-3: The first three satellites in the program provided relatively basic imagery, including cloud heights, temperatures, and wind data. The satellite's technical requirements limited how often the satellite's sensors could 'view' Earth.

GOES 4-7: The second group of GOES satellites were upgraded with the ability to take vertical soundings, enabling forecasters to analyze temperatures and moisture throughout the depth of the atmosphere. This capability proved beneficial for everything from hurricanes to dust storms.

GOES 8-12: An upgrade to the vehicle's stabilization and electrical systems afforded the next four satellites' instruments more power to work in tandem and continuously view Earth, providing forecasters more consistent and timely data during high-impact weather events.

GOES 13-15: Advanced technology built into the next three satellites continuously scanned the planet, giving us visible, infrared, and water vapor imagery at a relatively rapid pace. These satellites also included space environment monitors and solar x-ray imagers, monitoring events such as solar flares.

GOES 16-19: The current GOES family features much-improved spatial and temporal imaging. The satellites can take high-resolution visible and infrared images of the entire western hemisphere every 15 minutes, with scans of the U.S. every 5 minutes and small-scale rapid images every 30 seconds during high-impact weather events. In addition to a suite of space weather sensors, the new Global Lightning Mapper (GLM) tracks lightning flashes to aid forecasters monitor thunderstorms and hurricanes.