A strong high pressure cell located within the Tasman Sea is positioned in such a manner that will allow hot dry north westerly winds to prevail for a period of 4 to 5 days over southern and eastern Australia.
This should result in maximum temperatures for early October exceeding 30C for 4 to 5 days depending on location across a large swathe of southern Australia. The warm spell is expected to end during Tuesday and Wednesday as cooler air moves through.
The warm spell has commenced Friday with many inland western centres recording maximum temperatures reaching 30C to 33C with 33C being recorded at Lightning Ridge and Walget.
A big feature of this weather event is that it is widespread and is expected to reach coastal locations although places right on the coast such as Narooma and Ulludulla will not feel as much heat due to sea breezes prevailing.
Maximum temperatures of 30C are common in October including across Sydney however it is rare to have a period of 4 to 5 days in a row of such temperatures prevailing. This is expected to occur.
Another feature of this period is that temperatures are forecast to reach 38C and even 39C across limited regions of far south west New South Wales and far north west Victoria at places such as Mildura (Monday and Tuesday) and Balranald (Monday and Tuesday).
The Bureau of Meteorology (ACCESS Model) surface temperature for 2 pm for Sunday and Monday is showing the widespread nature of the heat expected to occur. The hottest regions on both days is likely to be far south west New South Wales (For southern Australia) and it is identified that western Sydney will heat up as well. A similar situation will prevail for Tuesday and at least for Wednesday although a cool change will be passing through that will end the current run of 30C temperatures.
Some forecast temperatures being made which provides an overview of what is occurring are:
Albury - Sat (29C), Sun (29C), Mon (31C), Tue (32C) and Wed (26C).
Balranald - Sat (35C), Sun (37), Mon (38C), Tue (38C) and Wed (26C).
Batemans Bay - Sat (32C), Sun (35C), Mon (32C), Tue (31C) and Wed (26C).
Blacktown - Sat (34C), Sun (35C), Mon (35C), Tue (34C) and Wed (34C).
Buladelah - Sat (32C), Sun (36C), Mon (37C), Tue (37C) and Wed (36C).
Dubbo - Sat (31C), Sun (33C), Mon (34C), Tue (34C) and Wed (34C).
Mildura - Sat (36C), Sun (37C), Mon (39C), Tue (38C) and Wed (26C).
Richmond - Sat (35C), Sun (36C), Mon (35C), Tue (36C) and Wed (35C).
Scone - Sat (31C), Sun (33C), Mon (34C), Tue (35C) and Wed (34C).
Sydney - Sat (28C), Sun (35C), Mon (30C), Tue (30C) and Wed (30C).
Wagga Wagga - Sat (30C), Sun (30C), Mon (32C), Tue (33C) and Wed (27C).
Based on this sample, the heat is expected to be widespread. The above places are chosen to show its widespread nature and to show that forecasts are being made for 38C at limited locations well away from the coast. Only the very coastal strip and elevated areas will not experience such warmth.
This will also impact northern Victoria but less so for southern areas of that state.
Bureau of Meteorology (ACCESS Model) acquired 2 October 2015.