It uses era5 data which is reanalysis. These models will always need the numerical training data. What's impressive is how well the emulate the physics in those

It uses era5 data which is reanalysis. These models will always need the numerical training data. What's impressive is how well the emulate the physics in those models so cheaply. But since the climate changes there will eventually be different weather in different places. https://www.ecmwf.int/en/forecasts/documentation-and-support https://www.ecmwf.int/en/forecasts/documentation-and-support