Since 2004, HEPEX (Hydrologic Ensemble Prediction Experiment; www.hepex.org) has fostered a community of researchers and practitioners around the world. During this time, it has contributed to establish a more integrative view of hydrological forecasting and to operationalize several techniques that contribute to enhance the accuracy and reliability of operational forecasting systems. Here, we present a summary of the main activities and achievements undertaken since the initiative started, but we also engage a discussion on how the community should continue its efforts: nearly fifteen years later, what else can HEPEX do to contribute to advance hydrologic ensemble prediction? What should HEPEX be in 10 years' time? The aim is to move forward with updated goals in order to better tackle the main challenges the community face today, almost fifteen years after the first meeting that launched HEPEX as a novel experiment in the international hydrological sciences community.