Air quality simulation models are extensively used in assessing the impacts of combustion plants. A wide variety of models are available. In order to recommend the most appropriate air quality modeling technique that should be incorporated into a standard regulatory framework in the Republic of Macedonia the performances of three Gaussian-plume atmospheric dispersion models, ADMS 3, OML, and ISCST3 have been analyzed. The models have been tested against the ground level measurements of the daily mean SO2 concentrations obtained at the four locations around the Thermal Power Plant of Bitola. Two experimental campaigns have been performed. The three model results and the measurements at the presented locations for 365 days in the year are compared. An analysis of the obtained results is presented in the paper as well. The meteorological preprocessor MADAM_MP has been used to provide the required boundary layer parameters for estimation of the transport and diffusion of pollutants released from the stacks. Using the MADAM_MP a year of hourly values for the mixing height, Monin-Obukhov length surface friction velocity, sensible heat flux, and Pasquill's stability class, have been calculated from the available meteorological data set. The approach and the main equations for the boundary layer parameters estimation are presented in this paper.