Toward improved short-term forecasting for Lake Victoria Basin. Part II: Preconvective environment analysis with ERA5

However, around 1000 fishermen die annually on the lake due to severe weather-related accidents. Radar-based research from the “High Impact Weather Lake System” (HIGHWAY) project in 2019 confirmed the marked diurnal cycle on Lake Victoria, studied over decades, where organized, intense convective systems pose a major risk to the fishermen operating overnight.

Building upon the results from Part I of this study, we investigate the preconvective environment over the lake for the modes that have been previously identified with a radar-based classification for the two wet seasons in 2019. ERA5 reanalysis data show that in 2019, instability and steeper low-level lapse rates were higher during season I [March–May (MAM)], allowing unorganized storms overnight to have stronger downdrafts, increasing the potential for strong and damaging winds over the lake.