The High-Impact Weather Assessment Toolkit (HIWAT) Streamflow Prediction Tool for Nepal provides 54-hour flash flood forecasts for 12,428 river segments in Nepal. The tool provides predicted estimates for flash floods from localized extreme weather phenomena like convective storms and thunderstorms. This tool complements information generated by the Streamflow Prediction Tool for Nepal and can be used as part of a decision support system for flood forecasting services. It can assist decision makers and managers in providing flood early warnings and response decisions during extreme events in small river catchments. Each river segment displayed in the map interface is colour-coded daily to indicate streamflow in the segment with respect to flood return periods.