On May 10th 2018, Hobart, Tasmania, was hit by an extreme rainfall event, which caused flash flooding, infrastructure damage and major disruption across the capital city. The event ranks as the second highest single day rainfall event in the city since 1960. With projections suggesting an increase in rainfall extremes across Australia, it is important to assess the role of greenhouse climate change in events such as this. Assessments of greenhouse attribution rely on climate models to characterise the expected signal. Daily rainfall extremes represent novel challenges for event attribution in models because the rainfall process is at least partly parameterised. It is therefore important to assess the statistics of daily extremes in climate models and the dynamical mechanisms that produce them. A necessary condition for projecting changes in extremes in models is to capture the underlying dynamics. Consequently, we assess whether the atmosphere-only HadAM3P model from the weather@home project can adequately capture both the distribution of these extreme rainfall events and the associated large scale atmospheric processes. This then provides confidence in the use of large model ensembles from the weather@home experiment to assess potential changes in the statistics of extreme one day rainfall events in Tasmania under greenhouse forcing. We draw no clear conclusions (either way) about the anthropogenic influence on very extreme rainfall days (like the autumn 2018 event), given the very small sample size of events of this magnitude. There are, however, indications that 1-day wet events in Hobart in a warmer world are associated with higher magnitudes but weaker circulation anomalies.