Numerical simulation techniques are used in Numerical Weather Prediction (NWP). Using the input from analyzed global telecommunication systems (GTS), different high resolution meso-scale models are being used in the laboratory for weather analysis and climate studies. The basic requirements of any NWP are climate or weather models and high performance computation facilities. The computational facility available at the laboratory: Server "Climate" is a multi-processor cluster with more than 48 processors and dedicated 12 TB of storage as well as accessory storage inputs in a dedicated server room with linked workstations. Out of many models, the laboratory focuses on using meso-scale models such as: Weather Research and Forecasting (WRF) model and Regional Climate Model (RegCM). WRF model with Advanced Research WRF (ARW) core is being used for most weather studies and weather forecasting. RegCM model is being used for detailed study of variability within the different seasons over different years of Indian climate.