Parameterization of the planetary boundary layer and vertical transformation of the unresolved turbulence is one of the most important physical problems of the atmospheric models. Cumulus convection on the environment, as the meso-scale phenomenon, releases latent heat and with vertical transfer of heat, humidity and momentum, moderate large-scale fields and atmospheric circulations. The study of various PBL schemas in the WRF model to predict hazardous phenomena such as heavy convective rainfall is the main goal of this research. Seven different PBL schemes investigated in the Caspian Sea coastline on the 5th-6th October 2018. The validation of parameterization by calculating absolute error and root mean square error showed that the configuration of the MYNN3 (PBL) and the MM5 (surface layer) had the lowest error in the third domain (9-km). Analysis revealed that the entrance of the cold front from the northwest of the Caspian Sea and severe drop of temperature in conjunction with the pass of a mid-level trough resulted to intensive activity of the system in the eastern plains of the Gilan and western Mazandaran. The intensification of convective instability with high water temperature and the supply of moisture from the Caspian Sea is apparent with the convergence of moisture flux at 925 hPa. Mountains in south of the region blocking the moisture flux, prevents airflow toward south of the Alborz, and in areas with the smallest distance between the coast and mountains, with co-operation the Sea breeze and the cold front, the heaviest rainfall occurred on a narrow strip.