Mirriam Mwende Musyoka (Kenya Meteorological Services Authority) - Convection in the Tropics: Seasonal Patterns, Hazards and Impacts, and Operational Forecasting and Nowcasting
Mirriam Mwende Musyoka talks about monitoring and forecasting convection in the tropics, with a focus on Central and East Africa.
Deep, moist convection is the principal producer of high-impact weather in the tropics and remains one of the most demanding forecast problems in operational forecasting in the tropics. This presentation reviews three interlinked themes. First, the typical seasonal patterns of tropical convection, i.e., the Zonal and meridional migration of the Intertropical Convergence Zone and the resulting monsoonal and bimodal rainfall regimes of equatorial regions, the afternoon-to-evening convective maximum, and the modulation of convective activity by intraseasonal variability such as the Madden–Julian Oscillation. Seasonal tropical cyclone activity in the Indian Ocean basin is also placed within the same framework. Secondly, it examines the major hazards from these convective developments and their impacts. Heavy rainfall and flash flooding, lightning, hail, damaging downdrafts and gust fronts, and visibility-reducing phenomena affect local populations through loss of life, displacement, damage to infrastructure and agriculture, and disruption of surface transport. Third, the presentation reviews the forecasting and nowcasting methods used operationally. The presentation will conclude by discussing how these tools are integrated into early warning services for high-impact weather scenarios.