Developing a user-focused flood forecast product for a continental-scale system

Floods are the most common and disastrous natural hazards, but early warning systems can help mitigate the damage by increasing preparedness. However, the products from these early warning systems must be skilful and actionable to be useful in the event of a flood. The European Flood Awareness System (EFAS), part of the European Commission's Copernicus Emergency Management Service, provides complementary flood forecasts to EFAS partners across the whole of Europe. One forecast product provided by EFAS is the ‘post-processed forecast product’ which is generated for the location of approximately 1600 river gauge stations where sufficient historic and near-real time river discharge observations are available. The aim of this product is to provide an error-adjusted forecast up to a maximum lead-time of 15 days. However, the post-processing methodology and the product design of the post-processed forecast product has not evolved over the past few years and therefore may not satisfy user’s changing requirements nor benefit from recent scientific advances. Following a skill assessment of the EFAS post-processed forecasts and a consultation with the EFAS partners a roadmap for future developments of the EFAS post-processed forecast product was designed. Here, we present this roadmap, and the results of the first stages, which include increasing the temporal resolution to 6-hourly timesteps, improvements to the post-processing methodology to better account for the different hydroclimatic regimes across Europe, and changing the post-processed forecast product to make it more locally relevant and useful to the EFAS Partners.