Evaluation of Traditional and Numerical Meteorological Models for Rainfall Onset in the Zanzibar, Dar es Salaam and Iringa (2015–2025)

21 Oct 2026, 14:55
20m
Conference Room 1 (BlueBerry Villas, Eldoret)

Conference Room 1

BlueBerry Villas, Eldoret

Off Eldoret Kisumu highway before the Kapseret by pass
Article / Full paper Cross cutting areas

Speaker

Mr Moses Machunda (Dar es Salaam Institute of Technology)

Description

Accurate rainfall onset prediction is essential for agricultural resilience across Zanzibar, Dar es Salaam, and Iringa. This study evaluates the traditional 4-Season temperate model against RegCM4 (regional), CAN-SIAM (climatological), and ECMWF/IFS (global). Results reveal a significant predictive gap, with observed onset exhibiting strong interannual and regional variability, while traditional models—especially 4-Season and CAN-SIAM consistently show delayed onset biases of 6–13 days. Analysis of 2015–2025 rainfall patterns indicate increasing variability in the Masika season, driven by dynamic convective processes. ECMWF/IFS demonstrates the highest agreement with observations (R² = 0.525), though all models underestimate rainfall intensity. The 4-Season model is found unsuitable for tropical applications due to its inability to capture rapid monsoon onset dynamics. These findings highlight the need for dynamic, data-driven forecasting approaches to improve agricultural planning and early warning systems in Tanzania.

Title Evaluation of Traditional and Numerical Meteorological Models for Rainfall Onset

Author

Mr Moses Machunda (Dar es Salaam Institute of Technology)

Co-authors

Presentation materials