Different parts of Australia will experience temperatures more than 40C apart, as twin hot spells and cold fronts sweep across the continent.
The phenomenon of thundersnow could strike alpine regions of Victoria this week, while rural Queensland swelters through 40C days.
According to the bureau of meteorology, a cold front is sweeping across southern Australian, including Tasmania, Victoria and southern New South Wales, at the same time as hot air lingers over Queensland and northern NSW, producing the extreme variation.
In Queensland, Cloncurry is forecast to hit a maximum of 39C on Thursday, with Longreach forecast for 40C and Julia Creek 41C.
Total fire bans have also been declared for Queensland and large parts of northern NSW.
In Victoria, Mount Baw Baw will experience minimums of -2C from Friday to Sunday. Combined with bad weather, this could lead to the combination of thunderstorms and snow, known as thundersnow.
Katarina Kovacevic, a meteorologist from the bureau, said this was not uncommon.
“Expect snow over the ski fields and the alpine regions,” she said. “This is pretty typical for this time of year and snow in October is not uncommon.”
“We saw some storms over north-east Victoria, over the elevated peaks. A line of storms moved through a couple of hours ago. There is a chance we could see some storms continuing this afternoon, and because the air mass is so cold, if a storm were to develop, any precipitation that would form would probably land on the ground as snow.”
Thundersnow had also occurred in August, when a cold front swept across Victoria, South Australia and NSW.
Kovacevic said the twin hot and cold spells were not out of the ordinary.
“The temperatures over the north of country are being caused by a pool of hot air, which is kind of typical for this time of year, particularly over northern parts of Western Australia.
“We have a cold front moving through north-east NSW and south-east Queensland and that is helping to draw the hotter conditions further east. Especially over the inland areas, where it doesn’t have the moderating influence of the sea.
“Over the southern part, over Victoria and southern NSW, we’ve seen a cold front …That is not uncommon for spring. Spring is a very changeable time of year.”
On Thursday, Brisbane was forecast for a maximum of 33C, compared with a high of 15C in Melbourne and 16C in Hobart. That disparity is poised to widen, with both Melbourne and Hobart forecast for a minimum of 7C on Friday.
In NSW, Sydney was set for a maximum of 28C on Thursday, with even hotter conditions inland. The bureau predicted 33C in Bellingen and 29C in Cessnock.
On Wednesday, the NSW Rural Fire Service confirmed that 64 homes had been destroyed in bushfires last week.