The emissions of plants, facilities or traffic routes can influence the environment due to pollutants. Wind field models can be used to forecast the resulting contaminants. If complex terrain exists, the simple methods fail. Prognostic mesoscale wind field models may be used to overcome this problem. The standard serves to evaluate such models for dispersion calculation, e.g. by steep terrain. The included evaluation instruction enables to retain the quality of mesoscale models on a high quality level and to standardise the method on an expanded basis. The developer of such models gets a guideline for quality assurance. The user gets test procedures and further information how to control and check the model calculations. Furthermore he gets criteria for choosing the right model for his purpose.