Nowcasting of precipitation systems

Abstract
Digital remotely sensed observations of the atmosphere, particularly from radars and satellites, have become increasingly available over the last 15 years. Together with developments in computer technology this has stimulated the design and operation of a variety of systems to exploit these data in weather forecasting. Growing awareness of the importance of detailed site specific weather information and forecasts from zero to a few hours ahead has led to the emergence of a particular kind of forecasting called nowcasting which depends on the exceptionally detailed knowledge of the current pattern of weather that remote sensing can provide. This type of weather forecasting is reviewed, with emphasis on the measurement and extrapolation up to about 2 hours ahead of fields of various weather parameters, especially rainfall. Trends in the design of nowcasting systems are discussed, and potential benefits summarized.