A significant heatwave is forecast to envelop southern inland Australia over coming days from the 5 to the 8 December 2015. A feature of this heatwave is that it is unlikely to reach coastal New South Wales or Victoria and hence it is likely to remain an event for inland areas.
The heatwave will cross through South Australia during Saturday to Monday, then into northern Victoria and western New South Wales but further east and south, maximum temperatures are forecast to moderate.
For New South Wales, there are areas along the coast such as the South Coast that are unlikely to reach 30C at any time during this period.
Some exceptionally high temperatures are forecast for inland areas of South Australia by Sunday including a forecast of 45C for Cooba Pedy and Tarcoola. Many inland centres of South Australia are forecast to reach 40C or higher for 2 or possibly 3 consecutive days.
Similar conditions are forecast for North West Victoria and western New South Wales during this period.
To provide some idea of the strength of this heatwave, the following maximum forecast temperatures are being made:-
South Australia
Adelaide - Sat 39C, Sun 40C, Mon 38C.
Ceduna - Sat 42C, Sun 41C, Mon 33C.
Coober Pedy - Sat 42C, Sun 45C, Mon 38C.
Keith - Sat 39C, Sun 39C, Mon 39C.
Leigh Creek - Sat 40C, Sun 43C, Mon 39C.
Tarcoola Sat - 43C, Sun 45C, Mon 39C.
Woomera Sat - 40C, Sun 44C, Mon 39C.
This shows that Sunday will see significant heat building across inland areas of South Australia.
A feature for Adelaide is the forecast for overnight minimums of 26C for Sunday and Monday night making for two uncomfortable warm nights should that occur.
Victoria
Bendigo - Sat 36C, Sun 37C, Mon 36C, Tue 33C.
Echuca - Sat 37C, Sun 39C, Mon 38C, Tue 35C.
Horsham - Sat 39C, Sun 38C, Mon 38C, Tue 33C.
Mildura - Sat 40C, Sun 42C, Mon 42C, Tue 37C.
Ouyen - Sat 39C, Sun 41C, Mon 41C, Tue 36C.
For Victoria, the city of Bendigo appears to be the southernmost limit where the heatwave takes hold. Maximum temperatures moderate for places further south and south east. Hence the significant heat should remain across the North West and Wimmera regions.
New South Wales
Balranald - Sat 38C, Sun 40C, Mon 39C, Tue 36C.
Broken Hill - Sat 39C, Sun 41C, Mon 41C, Tue 36C.
Finley - Sat 36C, Sun 38C, Mon 36C, Tue 32C.
Tibooburra - Sat 41C, Sun 42C, Mon 43C, Tue 37C.
Penrith (Western Sydney) - Sat 31C, Sun 32C, Mon 28C, Tue 32C.
For New South Wales, places like Finley appear to be at the eastern edge of the area worst affected by the heat. For places further east such as Albury, only one day is expected to reach 37C being Sunday. Penrith is added to show that the heat will not reach Sydney.
However places across the western interior are expected to swelter in at least 3 days of 40C temperatures or higher.
The attached plots from the Bureau of Meteorology Access Models show the following:-
1 - The heat forecast to impact the western inland of New South Wales for 2 pm Monday afternoon.
2 - The significant heat forecast to impact South Australia for 2 pm Sunday afternoon. In this model, it is suggested that portions of the state North West of Adelaide are forecast to reach 44C to 46C for Sunday afternoon.
3 - Australia showing the heat across South Australia for 2 pm Sunday afternoon which is clearly evident when compared to the rest of Australia. It is suggested that parts of South Australia will be the hottest locations found anywhere in the country at this time.
Much of South Australia has endured two hot to very hot days with some interesting maximum temperatures to note, especially during Sunday. During Saturday, much of the state endured maximum temperatures as high as 43C, especially for areas away from the coast.
Maximum temperatures for Saturday include:-
Tarcoola 43.3C – At 9 am, a temperature of 31.9C was recorded.
Port August 41.4C.
Roxby Downs 41.3C.
Maree 41.2C.
Pallamona Aerodrome 40.6C.
Adelaide and Woomera 39.8C.
Renmark 39.7C.
Sunday, another hot to very hot day occurred although a cool change brought relief for some areas.
Maximum temperatures for Sunday include:-
Maree Airport 44.1C.
Port August 43.9C.
Roxby Downs 43.5C.
Woomera 43.4C.
Renmark 42.8C.
Roseworthy 42C.
Nuriopta 41.1C.
Mildura (NW Victoria) 41.1C.
In addition to the above at Roxby Downs, the temperature fell below 30C at 2 am but reached 30C at around 8 am Sunday morning.
At Port Augusta, a minimum temperature of 22.8C was recorded at 6 am Sunday morning. Remarkably, it was still 30.5C at 3 am Sunday morning before dropping to 22.8C. By 7.30, am the temperature soared back to 32.8C and 40.4C was reached at 10 am.
The heat spilled into western New South Wales as expected with 41.2C recorded at Fowlers Gap.
Such heat is causing concern for fire fighters and there are fires burning although fortunately, they are not significant at this stage.
Monday 7 December 2015 was the third day of the heatwave across western New South Wales, North West Victoria and eastern South Australia.
Some high maximum temperatures for Monday include:-
Renmark (South Australia) 41.6C.
Mildura (NW Victoria) 41.5C.
Fowlers Gap (New South Wales) 41.5C.
Wilcannia (New South Wales 40.9C.
White Cliffs (New South Wales) 40.8C.
Walpeup (NW Victoria) 38.5C.
Lameroo (South Australia) 38C.
Yunta (South Australia) 37.7C.
This makes day 3 of the heatwave afflicting that region.
A big feature is the lack of cooling overnight with overnight minimums staying above 30C at some centres as shown.
Mildura
6 am temperature 30.4C.
8 am temperature 29C.
9 am – The temperature was over 30C but fell to 26.9C by 10.25 am. By 2 pm, the temperature had soared to 40.5C.
From 8.30 am Sunday to 6 am Monday, the temperature was above 30C was 21.5 hours.
Renmark – South Australia
The temperature at 4.30 am was 30.2C. At 8 am, it was 30.5C and 40.4C was reached by 10 am. The minimum temperature occurred at 4.30 am making it a hot night for the residents.
Yunta – South Australia
The overnight minimum occurred at 12 am being 28C. By 3 am, it had warmed to 34.4C but cooled slightly to 32.1C by 7 am. This would have made it very uncomfortable for sleeping.
White Cliffs – New South Wales
A minimum temperature of 31.5C occurred at 6 am. This town sweltered through 3 days of maximum temperatures above 39C.
This level of heat did not make it further east where temperatures moderated considerably.
The worst of this event is over and overnight fairly dry thunderstorms impacted portions of South Australia producing at least 140,000 lightning strikes especially across Eyre Peninsula, Yorke Peninsular and Mt Lofty. Rainfall from this event was relatively low with the maximum falling at Gawler where 14 mm fell. This event has come at the end of the heatwave.