The forecast chart on the left represents the 72-hour forecast of mean sea level pressure and wind speed a few km above the surface.

This specifc chart was produced at the European Centre for Medium-Range Weather Forecasts (ECMWF). To produce this chart, complex mathematical equations need to be solved by the world’s fastest supercomputers. In addition, worldwide meteorological observations are required to define the initial conditions of the atmosphere. This is referred to as Numerical Weather Prediction (NWP).

This Wikipedia article reveals the interesting story of NWP, from its beginnings in 1922 up to the present.

Cool reading about a still fairly unknown aspect behind the weather forecast.

Photo from ECMWF.