This region, part of which borders the east Atlantic Ocean, falls within the wettest area of West Africa. During the last three or so decades of the 20th century, summer precipitation deficits featured more prominently in the observed rainfall time series. There is little or no consensus among the models in projecting the likely shift in the mean precipitation during the 21st century. The GFDL CM2.0, GFDL CM2.1 and MPI ECHAM5 models project an upward rainfall trend while the remainder of the selected models show a drying trend. Whether the late 20th century precipitation deficits will continue into the 21st century and beyond is therefore uncertain from these results.
The selected models give a good representation of the observed 20th century annual cycle albeit shifting the rainfall maxima two or so months (behind by some models). There is no clear evidence of a meaningful change in the amplitude of the annual cycle during the summer months.