Hi @ivo! I am also curious about this topic. As I understand ECMWF is the model weather files/forecast is modeled in, and forecasts are produced of several met offices use in Europe. For what I know Yr.no (Norwegian Met Office) has more detailed topography, we often find their forecasts to be more accurate than i.e British Met Office.
Is this correctly understood? In case, is the yr.no data included in windy.com?