Skill of Sahel rainfall variability in four atmospheric GCMs forced by prescribed SST

The inter‐annual and long‐term variability of July–September regional rainfall over the central and western Sahel (16°W–20°E; 11.25°–18.75°N) is evaluated using 21 runs from four atmospheric general circulation models (AGCMs) integrated from 1948. The skill is stronger at decadal time scales: each AGCM simulates quite successfully the rainfall decrease from the wet 1950–60s toward the dry 1970–90s although its amplitude is lower than observed. At inter‐annual time scales, the skill is smaller and decreases over time between the 1950–70s and the recent dry period; all AGCMs have a close to zero skill around the 1980s. This is not linked to a reduced AGCM sensivity to global SST but to their failure to reproduce the observed SST‐rainfall teleconnection changes, in particular the weakening (strengthening) linear relationship with the equatorial and southern Atlantic (equatorial Pacific).