Numerical Weather Prediction (NWP) is the current state-of-art methodology to provide weather prediction at different spatial and time scales to serve user community. The NWP uses a modeling system built up adopting the mathematical equations governing atmospheric motion, incorporating the physical processes through parameterization methods, solved applying numerical methods and carrying out large number-crunching calculations on high speed computers. The NWP products have their application in agriculture, aviation, transport, tourism, sports, industry, health, energy and many other social sectors. Several decision support systems of disaster management and risk assessment are dependent on meteorological information from NWP products. The purpose of this book is to present the basics of NWP in lucid form to those who seek an overview of the science of modern weather prediction. About the Indian Meteorological Society The Indian Meteorological Society (IMS), established in 1957, is a non-profit organization whose objectives are the advancement of meteorological and allied sciences, dissemination of the knowledge of such sciences both among the scientific workers and among the public, and their application to various constructive human activities. IMS has its headquarters in New Delhi, and it organizes national and international conferences, lectures and other events through its 30 local chapters. It awards prizes, fellowships, and honorary fellowships. IMS has recently embarked on a programme to publish a series of popular books that would demystify meteorology and its various components for common readers. This is the second book in this series.