We assess wet and dry multi-day rainfall extremes in southeast Australia and identify the associated synoptic and large scale atmospheric circulation in both observations and general circulation models (GCMs). We find that these extremes are associated with wave trains propagating in the polar jet waveguide. We then evaluate the GCM ability to capture the statistics of the extremes in terms of their frequency, duration and magnitude compared to observations, and the onset and decay of the associated synoptic scale and large scale atmospheric structures. We find that some models are “too wet” to adequately capture the observed duration of dry spells but not always wet enough to capture the magnitude of extreme wet events. Despite the inability of the models to simulate all extreme event statistics, we find that the onset and decay of the observed synoptic structures are well simulated in the models. We also show that the associated large scale wave train structures are reasonably well simulated by the models. The results provide some context for, and confidence in, the use of the coupled GCMs in climate prediction and projection studies for regional extremes.