During Monday and Tuesday a complex low pressure system developed over the inland, leading to widespread damaging winds.

The system also generated the most severe storms this side of winter, with many locales receiving heavy rainfall and even large hail.

Northwestern Victoria picked up some huge falls, including Ouyen, which was swamped with 40 millimetres, its most in over two years, and its wettest September day since 1964.

Most of this region has now received somewhere between 125 and 200 per cent of their average monthly rainfall.

During Wednesday the system moved further east and cold, unstable southwesterly winds spread across Victoria and NSW.

Showers were driven over Victoria, but mostly south of the ranges.

More extreme rain and cold winds are on the way as a front approaches from the Southern Ocean.

The front will generate widespread rain, potentially severe storms and hail as it moves through the southeast from Friday.

Southeast SA can expect a further 10 to 20 mm with this system; Victoria 15-40 mm, and up to 100mm on the alps.