Deficiencies in cloud parameterizations in Numerical Weather Prediction (NWP) and General Circulation (GC) models are widely acknowledged to be among the most serious problems preventing the reliable predictions of weather and climate. It has been well recognized that ice clouds have an important impact on the Earth's climate by influencing the radiation balance and hydrological cycle. The distributions of mixed-phase clouds and the identification of cloud mixing process is also important for parameterization of cloud phase in NWP and GC models This book will explore some of these issues. The main focuses of the book includes analysis of cloud microphysical data collected in stratiform clouds, particularly, parameterizations of ice crystal shape, size and mass distributions and liquid fraction. The application and validation of some of these parameterizations in NWP and GCM models have been also discussed. This book is particularly useful for atmospheric scientists and graduate students who are interested in incorporating observational based cloud microphysical parameterizations in their NWP models or cloud remote sensing algorithms (Satellite and Radar).