Storm tracks are a key component of global atmospheric circulation. Their influence ranges from macro- to mesoscale dynamics, from large-scale movement of heat and momentum to extreme weather events. The scale of their impact makes understanding storm track dynamics critical to forecasting and climate projections. In this study, we assess CMIP6 historical experiment fidelity to observations of the Southern Hemisphere storm track. Specifically, storm track climatology, variability, and its interactions with low-frequency variability, with the aim of providing confidence for projections of future climate. We find CMIP6 models replicate results from the ERA-5 reanalysis with high fidelity in some regards; namely, capturing climatology of the 500hPa geopotential height field, the role of large-scale variability, and the baroclinic connection with high-frequency variability. However, models fail to capture the magnitude and variability of the storm track, particularly canonical zonal asymmetry. Our results indicate the importance of the storm track is underestimated in CMIP6.

The Southern Hemisphere storm track is a key component of the Earth's global circulation patterns, with a prominent role in the movement of heat and momentum across the mid-latitudes, and a controlling influence over the behaviour of synoptic eddies. Storm track characteristics are expected to change with anthropogenic forcings, leading to changes in regional weather patterns, and impacting communities through its influence on extreme events. We document projected storm track climatologies at the end of the 21st century under high- and low-emissions scenarios using the CMIP6 generation of models. We find previously described projections -- the poleward migration of the storm track, and intensification of storm activity -- persist in CMIP6. We explore projections of spatio-temporal variability of the Southern Annular Mode, and consequences for the storm track.