After a short burst of cold weather, a run of unseasonably warm weather is on the cards for south-east Australia.

A calm start to the week for the southeast of Australia is about to be disrupted in a big way as a major winter storm takes hold — and half the country could be impacted.

Wild weather systems from Western Australia and the Bass Strait are combining to deliver heavy rain, damaging, gale-force winds and freezing temperatures that will come with snow as low as 600m in some parts.

Sky News Weather Chief Meteorologist Tom Saunders says the storms from the west — that brought hail to some parts of the state — have already hit South Australia and are tracking towards Victoria.

That system will be followed by a major front on Thursday and a Polar low on Friday.

“We saw an area of high pressure sitting over the southeast on Monday,” Mr Saunders said. “But that area of high pressure rapidly weakening and moving to the northeast … will allow a series of powerful cold fronts to strike southeast Australia.”

I’ve spent most of this winter thinking Australia ‘doesn’t really have a winter’. And then this morning I woke up in Melbourne ❄️ pic.twitter.com/XM7SWr2jZI — Hamish Macdonald (@hamishNews) August 5, 2019

Melbourne be cold as as as 😩 — 🥥 Rene 🇼🇸 (@i_sopoaga) August 5, 2019

He said the first front — a band of rain from the west — will move across the country on Thursday.

A second system will move through Victoria on Friday followed closely by the low from the south that will carry wild weather north through New South Wales and parts of Queensland.

Damaging winds could cut power to thousands of homes and flooding is possible as some parts of South Australia get 25mm of rain and some parts of Victoria get double that amount.

The storm comes at a time where most capitals are experiencing chilly temperatures that will only get colder.

Sydney can expect the weather to turn from a pleasant maximum of 22C on Thursday to 18C on Friday, 17C on Saturday and just 16C on Sunday.

Melbourne — where it’s been a cold start to the week already — will see a maximum of just 13C on Thursday. That will drop to 11C on Friday and on Saturday and temperatures will reach just 12C on Sunday.

Canberra’s freezing mornings will continue. The nation’s capital will reach just 11C on Thursday before dropping to a miserable maximum temperature of just 8C.

In Hobart, the mercury will struggle into double digits with 12C on Thursday followed by consecutive days of just 11C and 10C.

Adelaide will be wet all week and just 13C on Thursday and Friday.

Perth is expected to bounce back from storms that brought hail and heavy rain earlier this week. Temperatures there will reach 17C on Thursday before climbing into the 20s for the rest of the week.

Brisbane will escape much of the tumultuous weather with mostly sunny days through until next week.

The rain is good news for farmers and the icy blast is good news for those headed to the alpine regions — it’s expected they could get as much as 50cm of snow throughout the week.