The start of spring is set to be wet and wild, with severe thunderstorms, heavy rainfall and hail on the way for much of Australia.
Bureau of Meteorology senior meteorologist Dean Narramore said a cold front and low pressure system was developing in southern Western Australia on Monday afternoon, with showers, isolated thunderstorms, small hail and gusty winds on the cards.
The one system will be responsible for a wet week across Australia as it slowly moves east before moving offshore on Friday night.
"On Tuesday the cold front will move into western South Australia with a band of patchy rain, isolated thunderstorms and showers will continue across much of southern WA, with local hail," Mr Narramore said.
"On Wednesday the front will move into central and eastern parts of South Australia and it's going to tap into some tropical moisture, not only from the Indian Ocean but also from the Coral Sea, so we're going to see the rainfall become widespread and also we're likely to see widespread thunderstorms, some severe, with large hail, damaging winds and heavy rainfall.
"On Wednesday night, that will move into south west Queensland, western New South Wales and Victoria as a band of rain and severe thunderstorms."
On Thursday with front will sweep across southern Queensland, northern New South Wales and all of Victoria with moderate to locally heavy falls possible, particularly with thunderstorms.
Mr Narramore said on Friday it will finally move into eastern New South Wales and south east Queensland.
That's not all though - Mr Narramore said after this week there are signs that another weather system could move through central parts of Australia on the weekend and early next week, with more rainfall.
"At least over the next seven to 10 days, we're looking at pretty wet and stormy first week of spring," he said.
Hail to miss most cropland
While hail is being forecast in Western Australia, Mr Narramore said it would be very localised,
"It will be very small with those cold air showers - just really tiny, almost sleet-like hail so no big impact there," he said.
However South Australia, New South Wales and Queensland could see more damaging hail storms.
"With those severe storms in South Australia, New South Wales and Queensland, generally it's going to be away from the agricultural areas, kind of well inland - more-so pastoralists rather than cropland," he said.
"But in saying that, some of these storms are likely to possibly see some large hail late on Wednesday through eastern parts of Australia and into southern Queensland and northern New South Wales on Thursday.
"It will be very localised, but of course if that localised goes straight over your farm it's not a good thing.
"We're not expecting widespread hailstorms like we saw in Mildura a few weeks ago, but a few areas could see localised pockets of large hail."
Mr Narramore said the system would bring most areas between 15 and 25mm of rain.
"It's actually looking like the weather series for the eastern parts of South Australia, western Victoria and then our usual wet spots on the western ranges of New South Wales will see more so 25-50mm," he said.
The September rain comes on the back of a wet August, where rainfall was 34 per cent above the 1961-1990 average for Australia as a whole.