This area falls within the dry area of West Africa whose 20th century time series is characterized by multidecadal rainfall fluctuations. During the last few decades of the 20th century, sequences of dry events were dominant. Even in this region there is a large uncertainty with respect to projected 21st century precipitation trends. While the GFDL CM2.0 and GFDL CM2.1 models project a significant downward trend, the MIUB ECHO-G models project an upward trend. The MPI ECHAM5 and CCCMA CGCM3.1 models predict insignificant wet and dry trends, respectively. Projections from the MRI CGCM2.3 model do not suggest any meaningful deviations of the 21st century mean precipitation from the 1901-1950 average.
The pattern of the observed 20th century annual cycle is acceptable well simulated by the models an exception being the MRI CGCM2.3 model which shifts the peak of the rainy season behind by one month or so. However there is a clear wet bias shown by all the models. A substantial reduction in the intensity of rainfall during the main rainfall season is predicted by the GFDL CM2.0 and GFDL CM2.1 models. The MIUB ECHO-G model predicts more intense precipitation in the future climate, though probably wrongly placed in time.