This work was supported by NOAA Cooperative Agreement NA67RJ0150. We express our gratitude to Peter J. Lamb for useful encouragement and suggestions. Helpful discussions with Laban Ogallo, Eugenia Kalnay, Kiku Miyakoda, Sylvio Gualdi, Vincent Moron, and Dave Montroy are gratefully acknowledged. The gridded rainfall data were taken from CRU dataset prepared by Mike Hulme (DETR, Contract EPG 1/1/48). Matayo Indeje kindly supplied the subregional rainfall indices, while the daily and monthly station rainfall data used in this study were kindly supplied directly by the Drought Monitoring Centre (Nairobi). We also appreciate useful comments from two anonymous reviewers.
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