SEVIRI Data Impact on Forecasting Storms over Lake Victoria using NCEP NMM-B Model

This study is moving the NCEP regional operational forecast model NMM-B and the data assimilation system NDAS to Europe and Africa, specifically centered over Lake Victoria. Lake Victoria in East Africa is one of the world's largest freshwater lakes and used on a daily basis by thousands of fishermen. Each year, severe storms on the lake cause multiple boating accidents which often result in fatalities. Here the NCEP regional model is evaluated along with a 12km parent domain and a 4km nested domain focusing on the high-impact weather. This study will also evaluate whether the SEVIRI (Spinning Enhanced Visible and Infrared Imager) radiance data can improve the severe storm forecast over Lake Victoria. SEVIRI is the instrument loaded on the Meteosat series of satellites that are geostationary meteorological satellites operated by EUMETSAT with the high spatial (3km) and temporal (15 minutes) resolution. Currently, two water vapor channels of SEVIRI are assimilated in NCEP global operational system, but not in regional for its coverage. In this study, both conventional data and SEVIRI radiance data are assimilated by 3D-Var data assimilation system (GSI) with hourly-updated cycle for both parent and nested domain.