Performance evaluation of a <scp>high‐resolution</scp> regional model over West Africa for operational use: A case study of August 2017

The frequency of flash floods resulting from heavy rainfall over West Africa has increased in recent years with serious socio-economic consequences. Therefore, the need to utilize numerical weather prediction models forecast events reliably is also rising at many operational meteorological centres Africa. This paper evaluates performance Consortium for Small-scale Modelling (COSMO) model German Meteorological Services (DWD) predicting high-impact that occurred between 19 and 26 August 2017. aims investigate synoptic forcings modulating daily variability during period. Results show COSMO simulates adequately spatio-temporal distribution Africa, though inherent biases. displays a decreasing skill producing spatial as amounts tend 30 mm above. Additionally, areas rainfall, mostly about 100–300 km southwest core Easterly Jet (AEJ), often coincide mean sea level pressure least 0.6 hPa increasing convective available potential energy 500 J/kg. Although not all cases, trough Wave (AEW) always located east these areas. We every storm, especially prime meridian, associated an AEW trough. able reproduce atmospheric dynamics variability, addition capturing propagation trough, AEJ. However, reproducibility may transform into predictive rainfall. Nevertheless, forecasters be determine likely by estimating position AEJ based on falling COSMO. Finally, incorporation fractions score metric neighbourhood approach could assist decide which scale severe alert can issued.