\section{Introduction}
East Africa has been undergoing increased frequency and intensity of droughts in recent decades, raising the question of whether the drying trend will continue in a warmer future climate as forced by anthropogenic emissions of greenhouse gases (GHGs).  Some studies proposed that the recent drying trend can be attributed to SST anomalies over the Indian Ocean induced by anthropogenic forcing \citep{Funk_2008, Williams_2011},  suggesting an extension of the current drying trend into the near future. However, there is a strong consensus in model projections from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) and the more recent Coupled Model Intercomparison Project Phase 5 (CMIP5, \citet{Taylor_2012}) that precipitation over East Africa will increase \citep{Shongwe_2011, Otieno_2013a, Otieno_2013b}, implying that the current dry conditions will be, at least partly, ameliorated in the near future.