Operational Nowcasting Based on Satellite Cloud Motion Winds

Most works and studies on satellite-derived cloud motion winds focus on their extraction and quality control, and on their impact on numerical weather prediction models. But cloud motion winds also provide important real-time information on current cloud movement, thus being a valuable input to short-range weather prediction. This paper addresses this important practical aspect and discusses the use of cloud motion winds for operational nowcasting. It describes how the CineSat software package computes real-time cloud motion fields and converts them into several nowcast products, like predicted satellite images, predicted cloud trajectories, cloud development maps, and smoothly interpolated weather animation movies. CineSat has been validated at two European meteorological institutes for more than a year and is also used successfully in the demanding field of air traffic control. The predicted satellite images turned out to be valid and plausible for up to 3 hours ahead in the infra-red channel, and more than 4 hours ahead in the water vapour channel. All CineSat forecasts are available in real-time, i.e. about 3-5 minutes after reception of the latest satellite image. The paper shortly describes the basic concept and methods, the built-in applications and most important it gives an overview on the rich palette of practical applications of cloud motion winds at several meteorological institutes.