Sizzling heat will be felt from Melbourne to Canberra and Sydney this weekend ahead of a cold front that will bring thunderstorms and much colder air in its wake.
Melbourne will experience the hottest day since January as temperatures soar to around 41 C (106 F) on Saturday. Gusty north to northwest winds will accompany the heat elevating the threat for wildfires in the surrounding region.
A cold front will arrive on Sunday, but not before temperatures reach a morning high of 37 C (98 F).
Showers and thunderstorms will bring heavy rain and strong winds to the Melbourne area on Sunday, leading to localized flash flooding and power outages.
Behind the front, much colder air will rush in from the south causing temperatures to fall to 20 C (68 F) by the end of the day.
The high temperatures on Monday will reach only 19 C (66 F).
This frontal boundary will also bring much colder air to Canberra and Sydney on Monday, but not before scorching heat dominates the weekend.
High temperatures will range from 36-38 C (96-100 F) in Canberra and 32-34 C (90-93 F) in Sydney this weekend. Gusty northwest winds will add to the high fire threat across the Australian Capital Territory and New South Wales.
The heat has already resulted in the cancellation of all Victorian horse races in Sydney on Saturday.
Thunderstorms will roll into Canberra Sunday night into Monday.
While there can be some downpours, the greatest concern with these storms will be strong winds.
Temperatures will plummet on Monday with a high of only 25 C (77 F) in Canberra and Sydney.
In Sydney, the storms will hold off until Monday, when downpours and locally damaging winds are possible during the afternoon.
While southeastern Australia gets relief from the heat early next week, the first tropical system of the season is expected to form in the Gulf of Carpentaria.
This potential cyclone is expected to bring heavy rainfall to northern Queensland during the second half of next week but will dissipate over the region with no impacts expected in New South Wales or Victoria.