Earlier this month, Environment and Climate Change Canada (ECCC) and Global Water Futures (GWF) convened the 2nd Annual Canadian Flood Forecasting Forum. Inviting also researchers and practitioners from National Oceanic and Atmospheric Administration (NOAA) and European Centre for Medium-Range Weather Forecasts (ECMWF), this forum aimed to advance a Community of Practice and develop relationships between flood forecasting agencies. The forum provided an opportunity to dive into the practice of flood forecasting from the continental to the local scale, including innovations in hydrological modelling and flood risk communication.

Hydrological forecasting is becoming a global enterprise with the development of large (continental or global) domain scale systems. A key challenge of tapping into international efforts and scientific development, is making forecasts relevant at a local scale. To bring this context, Canadian provincial and territorial forecasters were invited to present their current efforts and what service they would want from continental scale forecasting centers. Two-way communication between large domain and local scale was an emergent theme, as was the opportunity for translating scientific advances into operational practice. Forecasts are increasingly being extended into probabilistic ensembles and through visual tools for the public, including forecasted flood inundation areas.

While not the only framework presented, Delft-FEWS was a clear system of choice for many forecasting centers in North America. For example, Delft-FEWS enabled transboundary collaboration between a US and Canadian provincial forecasting center, allowing exchanges of staff for capacity building along with data-sharing. Advances in satellite monitoring of river ice, a key risk in many cold-regions, are also occurring in Delft-FEWS through collaborative governmental and academic research. The uptake of Delft-FEWS systems across Canada is helping to drive common tool development and enabling jurisdictions with limited capacity to access state-of-the-art tools and modelling.

Flood forecasting in cold regions and large geographic areas provides unique challenges. This forum was a great demonstration that a community approach is needed, and that comes from engagement and communication. International collaboration is essential to not only meet transboundary agreements, but to share experiences and best practices. The Delft-FEWS global community has a great deal to offer, but it may be that knowledge sharing is limited to the annual International User Days and users of Delft-FEWS software. Best practices such as forecast verification could be more widely shared inside and outside the user community.

An outlook and outstanding question from the Canadian Flood Forecasting Forum is how large domain hydrological forecasts can be effectively used by local forecasting centers. These systems provide a potential wealth of information, particularly in under-served areas. However, the optimal use of these forecasts, reliability, and complement to local modelling remain outstanding questions for the community at large.