One of the WCRP great challenges is the focus on changes in water availability and in particular on the ability of the scientific community to be able to understand and predict precipitation variability and change. By improving the observational system both based on in situ observations and satellite observations, the model validation is becoming more and more accurate and this will allow us to improve our understanding of atmospheric and land surface processes and finally to better predict precipitation. This will in turn affect the quality of the prediction of the hydrological cycle across several scales, from catchments to regional to global. On the other side the regional climate model community and CORDEX is moving towards very high-resolution simulation ensemble effort down to the scale of the convective permitting resolution (1-3 km). This will open new frontiers for the hydrological model community because this will bridge the spatial scale gap between regional climate models and impact models (hydrological models, ecosystem models etc.) community. This workshop will focus on the state of the art of: -Precipitation measurements. What can we use to validate precipitation coming from the model output? -Ensemble of high-resolution regional climate model outputs. How can those be used as input of a hydrological model? -Uncertainty in global and regional climate projections. How can this uncertainty be taken into account for hydro-climate simulation?