Abstract:
This article evaluates the ability of the Coordinated Regional Downscaling Experiment
(CORDEX) regional climate models (RCMs) in simulating monthly rainfall variation during
the austral summer half year (October to March) over southern Africa, the timing of the
rainy season and the relative frequencies of rainfall events of varying intensities. The phasing
and amplitude of monthly rainfall evolution and the spatial progression of the wet season
onset are well simulated by the models. Notwithstanding some systematic biases in a few
models, the simulated onset and end of the rainy season and their interannual variability
are highly correlated with those computed from the reference data. The strongest agreements
between the reference and modelled precipitation patterns are found north of about 20∘S in the
vicinity of the Inter Tropical Convergence Zone. A majority of the RCMs adequately capture
the reference precipitation probability density functions, with a few showing a bias towards
excessive light rainfall events.
