A flood forecast chain, developed at the Centre of Excellence for Remote Sensing and Hydro-Meteorology (CETEMPS) and based on coupled mesoscale atmospheric and a newly developed distributed hydrological model with in-situ and remote sensing data integration, is illustrated. The focus is on small-catchment flood forecast in complex topography in Central Italy, but the developed modelling and processing integrated tools may be easily applied to any geographical and orographic scenario. Emphasis is put on the integration of numerical models and retrieval algorithms with aim to provide an overview of an objective system for hydro-meteorological alert-map emission. As an example, the forecast hydro-meteorological chain is applied to a case study of an extreme event on 23–25 January 2003 and results are discussed.