The last three months of the year are looking to be warmer and wetter than usual in many areas.
First, let's look at recent conditions.
September temperatures have been near average for large parts of Australia, cooler in parts of the south-west and warmer in the north-east.
September rainfall has been below average for much of southern and south-eastern Australia, and parts of the east coast.
However, large parts of the country had above average rain, including much of the tropical north. Cairns had its highest monthly September rainfall on record.
Heavy rainfall on the 11th brought flash flooding to Sydney and its wettest September day since 1879. Many sites in the Sydney Metro district exceeded their monthly average rainfall in one day.
While rainfall deficiencies have improved in south-western Australia, parts of the south-east continue to be very dry for the year to date.
As a result, soil moisture remains below average for parts of the south.
However, many areas have above average soil moisture following recent rainfall, especially in south-western and north-eastern parts of Australia, as well as western Tasmania and eastern and northern NSW.
Overall, Australia's total water storage is currently around 70%.
Many storages in eastern Australia are at or near capacity.
In contrast, some storages in the south are less than half full.
In September, streamflow was above average across most of the east, north-west, and south-west.
However, streamflow was below average for much of south-east Australia, with some sites east of Melbourne setting record lows for September.
Looking ahead, the long-range forecast shows …
Above average October to December rainfall is likely for much of the eastern half of Australia, especially northern Queensland as the northern wet season begins.
Rainfall is likely to be in the typical range for much of the west, tending to drier than average for south-western Tasmania.
Full storages and wet soils, together with the forecast for above average rainfall, means an elevated risk of flooding over the coming months in the north and east of the mainland.
Daytime temperatures for October to December are likely to be above average across most of Australia.
Minimum temperatures are also very likely to be above average across the country.
There's an increased chance of unusually warm nights across Australia, especially in the tropical north which is approaching its warmest time of year.
As we enter the warmer months, the risk of heatwaves and bushfire increases. There is an elevated risk of fire in Australia's south-east, and in the Kimberley region of Western Australia.
Sea surface temperatures for October to December are forecast to be warmer than average across much of the globe, including around Australia.
In the Pacific, the El Niño-Southern Oscillation is neutral. However, La Nina development is possible over spring.
To our west, a negative Indian Ocean Dipole event is underway, which can be associated with increased rainfall over southern and eastern Australia during the spring months.
In summary, our forecast for October to December shows:
above average rainfall for much of the eastern half of Australia including an elevated flood risk in parts of the east;
warmer than average days and nights across most of Australia;
And an increased fire risk in parts of the south-east and north-west.
We update the long-range forecast weekly, where you can find the latest maps for the weeks and months ahead.
Select your location on the website to
