Science question 1
Ensemble Nowcasting & Numerical Weather Prediction in cities at 100m of resolution
The first real-time experiment of very high resolution nowcasting & NWP systems, for international games occurring during summer, was done during the Pan-American Games in Toronto in July 2015 (Joe et al 2015). This system was based on the GEM model from ECCC at 250m of resolution, coupled inline with the TEB urban scheme and a fine description of the city characteristics. Joe et al 2015 indicates that “Objective evaluation (May–August 2015) showed improvements at the surface when compared with operational forecasts or with the 2.5-km HRDPS model and as verified for traditional meteorological variables of near-surface air temperature and dewpoint temperature, precipitation, and wind speed. This is attributed to the combined effects of high resolution and the inclusion of urban thermodynamic and aerodynamic effects.”
Concerning nowcasting, two scientific issues that are in state-of-the-art research are seamless and ensemble nowcasting. How urban settings and hectometric numerical simulation systems modify these scientific questions, and how they can be solved, is to be addressed in the framework of this RDP.
Ensemble methods are being implemented or planned as the basis for the future of numerical weather forecasting. For example, the deterministic run will probably disappear at the horizon of the Paris Olympics in Meteo-France kilometric AROME model forecasting chain. The uses of ensembles are also being developed in nowcasting systems, and the synergy between ensemble nowcasting and NWP for seamless weather prediction is also a scientific question to be addressed.