<p>In the northeast region of India, several hill ranges are prominent, including the east–west oriented Khasi–Jaintia Hills (KJH), the north–south oriented Assam–Burma Hills (ABH), and the Corner Mountain Hills (CMH), which form a near-right angle where the ABH and KJH meet. We study the effects of these mountains on the precipitation enhancement associated with airflow over the northeast region of India. To parameterize the precipitation enhancement during southwest monsoon season (SWMS), associated with baroclinic mean flow over the northeast region of India, a three-dimensional frictionless, adiabatic, laminar, inviscid, hydrostatic, Boussinesq and non-rotational moist airflow is considered. The basic flow has two parts: zonal wind part <i>U</i>(<i>z</i>) and meridional wind part <i>V</i>(<i>z</i>), and the Brunt-Väisälä frequency (<i>N</i>) is taken to be variable with height. We have analyzed the effects of different mountain barriers on orographic rainfall intensity (RFI) during the SWMS over the north-east region of India. The results of this model are compared to those of earlier researchers.</p>