Abstract This study presents a spatiotemporal analysis tool, called Shyska. This tool allows the simulation and prediction of flash floods in semiarid basins. Shyska has been developed by Geographical Information System (GIS)-embedded functions, allowing the integration of hydrometeorological information from modern technologies of data acquisition in real time. A Digital Elevation Model (DEM) is used in order to obtain the relevant parameters from the integrated rainfall-runoff models. Some of its most relevant modules and methodology employed for its development are described. Case studies in basins of south-east Spain illustrate the applicability of the proposed techniques.