A Large Eddy Simulation (LES) code, previously used for simulating the Planetary Boundary Layer (PLB), has been developed in order to take atmospheric conditions into account. The LES has been tested for neutral, stable and unstable PBL. The neutral simulation has been compared with previous studies and shows satisfactory results. The unstable simulation indicates that the implemented code works correctly, but further evaluation must be done. The same is true for the stable simulation.