PVA-maxima and their connection to cloud systems in satellite images and to precipitation

Summary PVA-maxima can be a contributor to upward motion; there-fore cloudiness and precipitation can be expected there. This is investigated from several viewpoints: grey shade evaluations of false colour satellite images are done, frequencies of precipitation events for PVA maxima and grey shade intervals are investigated, precipitation amounts within the PVA maxima path are compared to a surroundings and the predictability from the ECMWF model is proved. Several results could be derived: PVA maxima are accompanied by brighter grey shade intervals and a higher precipitation probability than surrounding areas; for the brightest grey shade intervals a probability for precipitation of 60–70% can be stated; the path of the PVA maxima is an area of more precipitation than in the surroundings; ECMWF forecasts are able to predict the PVA maxima and their location very well but tend to underestimate the precipitation amounts on the PVA maxima path.With 9 Figures