A burst of hot northerly winds will bring the highest temperatures in years to parts of south-east Australia this weekend, while ex-Tropical Cyclone Kirrily carves a trail of torrential rain and flooding across western Queensland and the eastern Northern Territory.
For New South Wales, the heatwave will rapidly transition into a tropical deluge on Monday and Tuesday, as the ex-cyclone finally departs Queensland, after a meandering 10-day journey that brought the heaviest rain in more than a decade to parts of the state.
Temperatures soar as outback air mass reaches NSW and VIC coast
This weekend will culminate in the hottest weather in up to three years across parts of South Australia, Victoria and NSW as maximums climb to about 12 degrees above averages.
The heat follows Australia's third warmest January on record — temperatures across the country were 1.54C above the 1961-1990 baseline average and around 2C above pre-industrial levels.
Sydney has been particularly uncomfortable this summer suffering through maximum temperatures nearly 3C above the long-term average and humidity nearly 10 percentage points above normal.
The hot air mass lingering across Australia's interior through January has persisted into the new month, and after a warmish Saturday, a northerly airstream will quickly carry the inland heat to south-east states.
Sunday's temperatures will climb above 40C for areas inland from the ranges, and to the mid-30s along the coastline, combining with freshening winds to bring "high" to "extreme" fire dangers.
Melbourne and Canberra are likely to reach 37C and 35C respectively, their warmest days since March, while other locations across Victoria, eastern SA and southern NSW should sweat through their highest temperature since 2021, including:
- Wodonga-Albury 40C – warmest day in three years
- Wangaratta 40C – warmest day in three years
- Wagga Wagga 40C – warmest day in three years
- Renmark 44C – warmest day in three years
A handful of other major centres are forecast to see their hottest weather in 12 months including Mildura 43C, Bendigo 38C, Ballarat 36C and Shepparton 40C.
When will a cool change arrive?
A cool southerly change will rapidly lower temperatures across SA and Victoria overnight Sunday, dropping maximums as much as 16C in 24 hours.
The change will reach southern NSW through Monday, however hot northerlies will continue further north, leading to another day in the mid to high 30s across Sydney, along with suffocating humidity.
Timing of the cool change for our capitals:
- Adelaide Sunday evening — 11C drop in 24 hours
- Melbourne before sunrise Monday – 16C drop in 24 hours
- Canberra late Monday – should cool down pre-change due to cloud
- Sydney Monday evening – 7C drop in 24 hours
The prolonged spell of summer warmth will again pass heatwave thresholds for most of NSW, including a severe rating across the eastern inland, while most of central and southern Queensland endures a low-intensity heatwave.
Cooler air from the south should gradually filter through northern NSW and southern Queensland from Tuesday to Thursday.
Ex-Cyclone Kirrily to flood eastern outback, including western NSW
It has now been well over a week since Cyclone Kirrily crossed the Queensland coast, and the system is still bringing torrential rain and flooding.
The centre briefly dipped off the Gulf of Carpentaria coast early Friday, but otherwise has remained landbound, dumping hundreds of millimetres of rain.
One of the most impressive figures was a 24-hour total of 332mm to 9am Friday at Westmoreland station near the NT border, the location's heaviest fall since April 2010.
After tracking north during the week ex-Tropical Cyclone Kirrily is now moving south again, traversing the NT/Queensland state line this weekend and triggering flood watches on both sides of the border.
The tropical low should bring a narrow band of around 50 to 200mm this weekend — west of about Cloncurry to Windorah, before the system accelerates into north-east SA and NSW on Monday, although some modelling holds off on its exit path out of Queensland until Tuesday.
When the former cyclone reaches NSW it has the potential to bring more than 100mm to the state's north-west.
However, even southern districts could be soaked by more than 50mm as moist air from the system interacts with the approaching cool change.
Below is a precipitation forecast from a leading global model showing the swathe of rain under Kirrily's path.
All future projections for Kirrily have the system finally decaying by Wednesday, however, a new low-pressure system in the Coral Sea is threatening to bring further heavy rain to Queensland later next week.