Large parts of Australia are now bracing for horror weather conditions today and into the weekend that could worsen the already disastrous bushfire crisis.

Sky News Weather meteorologist Alison Osborne told news.com.au huge areas of the continent were at risk in the hours to come.

"A strong cold front is developing in the west and will move through South Australia on Friday then the southeast on Saturday," Ms Osborne said.

"To the west of the front, winds across the east will shift northerly on Friday, directing a very hot and dry air mass across South Australia, NSW and Victoria."

Ms Osborne said the southern regions of South Australia would be significantly impacted by nasty weather conditions today, news.com.au reports.

"The southern regions of South Australia will experience very hot and windy conditions (with) temperatures well into the 40s and strong winds in a north to north-westerly, shifting to a south-westerly from west to east with the passage of the front," she confirmed.

Thick smoke blanketing southeastern Australia along the border of Victoria and New South Wales. Photo / NASA

"The change won't hit the fire-ravaged Mount Lofty Ranges until after sunset, making for another challenging day.

"Fires in these conditions become unpredictable, uncontrollable and fast moving."

South Australia Country Fire Service chief officer Mark Jones said the Friday forecast was alarming as existing blazes still had not been brought under control.

And the news is similarly worrying for Saturday, with temperatures across the already-stricken areas of eastern Victoria, the NSW southern ranges and the south coast set to climb to the 40s with north-westerly winds ahead of a cool change.

Ms Osborne said it was a "similar synoptic set up to New Year's Eve" when ferocious bushfires ripped through many communities, leaving a trail of death and destruction in their wake.

"Winds will be strongest along the coastal fringe, resulting in erratic fire behaviour and (a) shifting direction of fire fronts with the wind change, which should be over the Shoalhaven by early evening and Sydney by midnight," she said.

"Fires in these conditions (also) become unpredictable, uncontrollable and fast moving."

Kangaroos move as nearby property burn in a fire in Lithgow, New South Wales state, Australia. Photo / AP

Ms Osborne said the NSW town of Cooma was also poised to reach 40C – a temperature that would eclipse the previous all-time record of 39.5C.

The Bureau of Meteorology has also issued marine wind warnings for South Australia, with a strong wind warning for the far west coast, upper west coast and Spencer Gulf today and the lower west coast, central coast, Spencer Gulf and lower south east coast tomorrow.

The forecast comes as tens of thousands of people are currently being evacuated across NSW and Victoria in a race against time ahead of the catastrohpic conditions to come with the weather change plunging huge areas of Australia into the risk of disastrous fires on Saturday.

So far the total number of Australian bushfire victims this season stands at 20, with 16 deaths recorded in NSW, two in Victoria and two in South Australia.