@Josephaubrey41
A weather model like that of the ECMWF computes many parameters from a huge quantity of weather data from weather stations, soundings, planes and mainly satellites (90%). After the assimilation phase, the weather model computes these parameters. Wind is derived from pressure gradients which are computed at different levels.
Some general information about NWP
https://en.m.wikipedia.org/wiki/Numerical_weather_prediction