‘Near record’ temperatures set to scorch
Get ready to sweat as "near record high temperatures" look set to envelop south eastern Australia.
Parts of Sydney and Adelaide will sail past 30C later in the week, while 40C is forecast for regional South Australia.
Five-day heatwaves could be seen in inland areas including the Mallee, Broken Hill, Port Augusta and even Canberra.
As we approach the weekend those temperatures could dramatically drop, potentially by as much as 10 degrees in just few hours. Sydney could see a southerly bluster sweep through.
But then temperatures will rise again, possibly even higher, as a stronger second trough approaches early next week.
To escape the heat, head to Western Australia.
Sky News Weather channel meteorologist Tom Saunders said Victoria and South Australia had seen cool temperatures and early morning frost this week, "but that's all changing".
"We're expecting near record high temperatures to develop over central and southern Australia."
Adelaide could see 27C on Wednesday, then a dip to 22C on Thursday, but by Saturday the mercury could shoot up to as high as 33C.
Port Augusta is looking at 37C on Wednesday and 40C on Friday and Saturday.
What's causing the unseasonable heat?
"It's due to a high-pressure system moving out into the Tasman Sea. It is near stationery so we are stuck in a northern airstream over southern Australia for the rest of the week," said Mr Saunders.
Mr Saunders said the rotating high pressure system was dragging down hot desert weather from central Australia to the south.
"Temperatures will climb to well above average."
The first peak of heat will occur just prior to a low pressure trough rolling across the south. That will hit on Thursday in South Australia and Friday in Victoria. It often gets hotter just prior to a cold front arriving.
Melbourne will see a partly cloudy Wednesday with highs of 25C and 27C on Thursday. Then on Friday, it will struggle to get above 17C. However it will be back up to 27C on the weekend as the next cold front approaches.
It will be cooler in Hobart with a maximum of 20C on Wednesday followed by a peak of 27C on Thursday. Then, just like Melbourne further north, Tassie's capital could see temperatures slump by 10 degrees to 17C on Friday.
However, Hobart should see less yoyoing in the weather, with the mercury remaining around the late teens and low twenties for the weekend.
A string of warm days in Canberra with 25C on Wednesday, 27C on Thursday and 28C on Friday with much the same on Sunday after a brief dip to 22C on Saturday.
SYDNEY SEARINGLY HOT
It's warming up in Sydney with people warned to expect 25C on Wednesday and then a sweat-inducing 29C on Friday, a full eight degrees above average. In Penrith, in the city's west, it will go from 29C on Wednesday to a scorching 34C on Friday.
On Thursday, temperatures will dip as the trough produces a possible southerly buster, a dramatic drop off in the heat often accompanied by windy conditions.
The Bureau of Meteorology's Stephen Stefanac told news.com.au that cool breezes off the ocean would see inner-city and coastal Sydney get off far easier than inland areas.
Dubbo is looking at 35C on the weekend, Broken Hill could get to 37C.
However, a lack of strong winds should lessen bushfire dangers.
But this week's seesawing heat is just a taster, Mr Stefanac said: "It's not until we head into next week that we really may see some early season maximum temperature records."
If Dubbo passed 36.1C then it would be the hottest in the New South Wales central west city this early in October for at least 26 years.
Mr Stefanac said the second trough could lead to further heat spikes.
"One trough goes through on Friday but the heat will build on Sunday and Monday as the stronger trough approaches from the west."
Cloudy and 25C in Brisbane on Wednesday then sunny and rising into the high twenties, even getting to 31C on Saturday.
Highs of 29C with a possible shower here and there in Townsville.
Darwin is hot with a run of 35C sunny days and lows of 24C.
Finally Perth and it's relatively mild in the west. A high of 22C on Wednesday rising to 25C on Thursday then bobbing around 20C for the weekend. Some cloud and possible heavy rain on Friday.