Numerical weather prediction

Summary

Numerical weather prediction is the forecasting of the weather by solving the equations of atmospheric motion on a computer. It treats the forecast as an initial value problem. An estimate of the present state, obtained by data assimilation, is advanced in time by a discretised model such as the primitive equations. The first successful numerical forecast, with the barotropic vorticity equation, was made in 1950, and today it is the basis of all weather forecasts. Its skill is limited by model errors, by errors in the initial state and by the chaotic growth of those errors.