The structure, evolution and behavior of atmospheric boundary layer (ABL) is largely regulated by topography, land-surface characteristics, atmospheric radiation and synoptic conditions. Therefore, the mesoscale models like Weather Research Forecasting (WRF) are better suited for ABL studies. This book emphasizes upon the ABL characteristics over north Indian region during two contrasting synoptic situations of summer and winter. First chapter is introductory in nature. A brief description about the WRF modeling system is given in the second chapter. Third chapter describes about the study of regional scale boundary layer characteristics over north India. In chapter four, consequences of sensitivity experiments with different land-surface and boundary layer parameterization schemes are presented. To investigate the influence of finer resolution on the boundary layer characteristics, two-way nesting technique is implemented in the study described in fifth chapter by keeping the parent domain intact and the child domains configured with 5 km resolution over the three cities Delhi, Ahmedabad and Jodhpur.