The effective integration of wind energy into the overall electricity supply is a technical and economical challenge because the availability of wind power is determined by fluctuating meteorological conditions. This book offers an approach to the ultimate goal of the short-term prediction of the power output of winds farms. Starting from basic aspects of atmospheric fluid dynamics, the authors discuss the structure of winds fields, the available forecast systems and the handling of the intrinsic, weather-dependent uncertainties in the regional prediction of the power generated by wind turbines. This book addresses scientists and engineers working in wind energy related R and D and industry, as well as graduate students and nonspecialists researchers in the fields of atmospheric physics and meteorology.