Drivers of Subseasonal Forecast Errors of the East African Short Rains

The ‘short rains’ in East Africa from October to December have significant year-to-year variability. Their abundance or deficiency is often associated with floods droughts for which early warning crucial, though even normal seasons skillful forecasts facilitate planning and preparedness. Here we study the relationship between initial-state sea surface temperatures subseasonal rainfall forecast errors European Center Medium-Range Weather Forecasts model region. We demonstrate that initial mode of Indian Ocean Dipole (IOD) a partial control on error weeks 3–4. This also clear seasonal scale, exemplified by too-wet during 2015 season when IOD was positive, too-dry 2010 it negative. Our results provide an entry point improvement, show priori corrections based index are feasible.