The Role of Tropical Cyclones Idai and Kenneth in Modulating Rainfall Performance of 2019 Long Rains over East Africa

East Africa (EA) suffers from significant flood and drought risks. These can be alleviated with pre-emptive action; however, currently available knowledge on the influence of tropical cyclones in the south Indian Ocean on extreme rainfall over EA is limited. Extending knowledge on understanding the effects of tropical cyclones on the basis of their location could open a window for mitigating the devastating effects of flood and drought. The current study fills this knowledge gap by examining the impact of the poor rainfall performance from tropical cyclones Idai and Kenneth during March and April, which subsequently led to delayed onset of seasonal rainfall during March-May 2019. The study reveals the link between disruption of rainfall and the direction of moisture flow across EA. Findings revealed that the location of tropical cyclones Idai/Kenneth over the Mozambique Channel/northern Madagascar as a key driver of strong easterly flow over the northern region of Tanzania, Kenya and Uganda led to drier conditions. Simultaneously, the same location of the tropical cyclone was linked to Congo westerly flow over southern Tanzania that led to wet conditions. Tropical cyclone Kenneth interacted with the Mascarene High to sharpen the moisture flow across EA, which occurred unusually late in the season. Generally, these results build on the scientific evidence that the location of tropical cyclones may determine how the EA region is affected by either flood or drought. The current study provides new insights on the mechanisms that control the weather of EA, thereby leading to better forecasting accuracy.