It has been widely accepted that human influenced emission of green house gases are largely responsible for the climate change which we are experiencing currently. To produce detail information as a guide line for long term future climate change evolution arising from global warming, a projection approach is generally adopted to study the changes in regional climate. Regional climate modeling, as a part of down scaling techniques, to enhance the regional details due to geographical forcing is a very useful technique for over coming insufficient aspects of the GCMs such as narrow mountain ridges, complex terrain and complicated land sea contrasts. Several studies have mentioned that over the mountainous regions, the nested approach with a high resolution regional climate could improve simulation of physio-graphically relevant fields. By increasing resolution, the local effects play a significant role in the regions characterized by complex physio-graphics and are better resolved and more realistically simulated. This book comprises of three chapters. Detail descriptions and findings are given in chapters.