Since last decade, water availability has been identified as one of the main problem affecting earth population. Some areas within the Mediterranean Basin, are interested by an increasing reduction of available water resources that caused a progressive enhancement vulnerability of those zones especially caused by dry events. For this reason, the study and the monitoring of climatic situation and its evolution over those areas is of primary importance in order to reach a sustainable management of the natural resources.
An attempt to cover this information is represented by seasonal forecasts that try to predict, in a statistical framework, the spatial and temporal distribution of weather anomalies a few months into the future. Even though the detailed dynamical evolution of atmospheric systems is not predictable on those time scales, some of their statistical features and behaviours can be predicted. In particular it is possible to infer on the average behaviour over a month or season, and how much the probability distribution of such averages, or anomalies, differs from the "climatology". Since late 90's seasonal forecasts experienced a growing role, despite the large uncertainties still present.
Precipitation anomalies knowledge, available a few months early, could be useful for technical services and organizations on managing water resources, crop and energy. At the same time, methods and results of this recent branch of atmospheric sciences must be as simple and accessible as possible for any potential users. For this reasons, the Institute of Biometeorology developed a simple, physically ? based, statistical approach to obtain monthly outlooks, regarding rainfall anomalies over the Mediterranean basin, tuned for the summer period and based on the NCEP ? NCAR Reanalysis dataset. The forecasting strategy is a multi-regressive method based on physical atmospheric indices and sea surface anomalies.