In 1917 the Norwegian physicist Vilhelm Bjerknes introduced his theory describing the formation of wave cyclones on the polar front and laid the foundation for modern methods of weather forecasting. In 1922, L. F. Richardson perceived the basis for the mathematical prediction of the atmospheric circulation, and in 1938 C. G. Rossby made additional mathematical contributions. Application of this treatment by Richardson and Rossby awaited the introduction of high-speed electronic computers, which were first used for weather forecasting in the late 1940s by J. G. Charney and John Von Neumann. By 1955 computer forecasts were being made operationally and computer forecasting models have been improved steadily since then.
Since 1959 meteorological satellites have provided an overview of the atmosphere's cloud patterns, serving among other things as an early warning and detection system for hurricanes, typhoons, and tropical cyclones. Infrared sensors mounted on meteorological satellites now provide observations of the vertical temperature structure of the atmosphere, and research efforts continue the development of computer forecasting models capable of utilizing these and other satellite data to improve current weather-predicting skills. Meteorological studies have been aided by the use of large computers for atmospheric modeling. Information gathered by weather balloons and earth-orbiting satellites have been used in computer models to predict long-term and short-term meteorological events such as changes in ozone levels and daily movements of storms, respectively.
The National Oceanic and Atmospheric Administration (NOAA) has the major governmental responsibility in the United States for monitoring and forecasting the weather and conducting meteorological research. The Air Force Weather Agency and the Fleet Numerical Meteorology and Oceanography Center have similar responsibilities within the U.S. Air Force and U.S. Navy, respectively; space applications to meteorology are researched by the National Aeronautics and Space Administration (NASA) as well as by the National Environmental Satellite, Data, and Information Service, which is under the auspices of NOAA. In addition to a host of universities conducting meteorological research, there is the National Center for Atmospheric Research, which is operated by an affiliation of universities and sponsored by the U.S. National Science Foundation. The World Weather Watch, organized by the World Meteorological Organization, collects and disseminates information on a global basis. A number of private companies also engage in operational and research meteorological activities.