Ducted coastal ridging over S.E. Australia

The intense and rapidly established coastal ridging which is a regular occurrence over south‐eastern Australia during the warm seasons, is investigated using a detailed case study and mesoscale numerical model simulations. We suggest that the ridge is initiated by a forced Kelvin‐type edge wave which forms on the south‐western edge of the Great Dividing Range and is ducted, in an anticlockwise sense, around the coast. The ridge is then stabilized by inertial modification and decays over a synoptic time scale of a few days. Our results apply to similar phenomena in other parts of the world, notably southern Africa and South America.