A brief cold front is expected on the east coast of Australia, with rain, thunder and cool weather in Victoria, NSW, Tasmania and southern Queensland.
Sky News meteorologist Alison Osborne said the mercury would “plunge” from Wednesday due to a blast of polar air from Antarctica.
Victorians could see “quite cold and more wintry like weather” with below average temperatures of 15C, while similar conditions will be felt in NSW.
Temperatures are also expected to drop across Queensland throughout Thursday before warmer weather returns on Friday.
Thursday could also bring “showers and light hail across south-east Queensland on Wednesday afternoon, before light rain falls on the NSW north coast on Thursday.
“(Thursday) we see southeasterly winds moving into a trough of low pressure across NSW. This will draw moisture-laden air across NSW, leading to showers and thunderstorms,” Ms Osborne said.
By Thursday evening, wet weather will settle in with a mix of thunderstorms expected across south-east Queensland.
The Bureau of Meteorology predicts Sydney will reach a high of 25C on Wednesday, before dropping to highs of 19C and 12C on Thursday and Friday. A 70 percent chance of rain is also expected for both days.
There is a high chance of thunderstorms in Melbourne in the afternoon and temperatures will drop to 9C on Thursday.
Similar cold weather is also forecast for Hobart. After a rainy Wednesday, the mercury will struggle to climb above 14C on Thursday, with temperatures dropping to just 6C on Thursday.
Despite the cold break, the bureau has warned of high and extreme danger ratings for the rest of Australia. Temperatures in Western Australia, the Northern Territory, northern Queensland and the mid-north coast of NSW.
Ms Osborne said rain expected on Thursday could bring a much-needed break to bushfires on the NSW mid-north coast, including Kemps.
“But for many of the fire-affected areas in the Mid-North Coast and Valleys, you're likely to see a period of fairly steady rainfall — good rains that could lead to the fate of a few active fires.” said.