Numerical weather prediction involves the use of mathematical models of the atmosphere to predict the weather. Manipulating the huge datasets and performing the complex calculations necessary to do this on a resolution fine enough to make the results useful is the responsibility of NOAA’s National Centers for Environmental Prediction (NCEP). NCEP delivers national and global weather, water, climate, and space weather guidance, forecasts, warnings, and analyses needed to help protect life and property, enhance the nation's economy, and support the nation's growing need for environmental information.

		By 1954, both modeling capability and computer power had advanced to a point where the possibility of real-time operational numerical weather prediction was under active consideration in Europe and the United States. On July 1, 1954, the Joint Numerical Weather Prediction Unit (JNWPU) was organized, staffed, and funded by the U.S. Weather Bureau, the U.S. Air Force, and the U.S. Navy. This new unit was given the mission to apply emerging computer technology to the operational production of weather forecasts. Using a newly purchased IBM 701, by mid-1955, the JNWPU was issuing numerical weather predictions twice a day. These early forecasts offered no competition for the ones being produced manually. However, the operational environment in which the forecasts were produced provided the necessary impetus to rapidly identify modeling problems and implement practical solutions. By 1958, the forecasts being produced began to show steadily increasing and useful skill.
Jule Charney's 1948 Princeton group, build a mathematical model of the ENIAC to demonstrate the feasibility of numerical weather prediction (April 1950).

Continued Evolution of Numerical Weather Prediction - The evolution of numerical weather prediction throughout the latter part of the 20th century proceeded at a similar pace at many operational numerical weather prediction centers around the globe. The first numerical weather prediction models used in the United States ran on grids that covered the Northern Hemisphere. This restriction was based primarily on the amount of computer power as well as the amount of data available to initialize the model. However, a progression of more and more powerful computers procured by the National Weather Service throughout the 1960s and 1970s as well as increasing sources of data—particularly from weather satellites—allowed the expansion of both the domains and the number of models run.

Increases were also made in the number of vertical levels and the horizontal resolution of the models. A three-layer hemispheric model was introduced in 1962 and a six-layer primitive equation model appeared in 1966. Additional atmospheric layers allowed more accurate forecasts of winds and temperature, resulting in better prediction of storm motion.