The Bureau of Meteorology is forecasting a high chance of below average rainfall for large areas of Australia for June to August, along with warmer than usual temperatures.
The winter long-range forecast shows warmer than usual daytime temperatures are likely almost everywhere, and warmer nights are also likely for many areas, with cooler nights for western New South Wales, parts of southern Queensland, eastern South Australia and southern areas of the Northern Territory.
Bureau of Meteorology Extended Prediction Technical Lead Catherine Ganter said there was a high chance of below average rainfall, particularly in southern areas of Australia.
‘Southern areas have at least twice the normal chance of winter rainfall falling in the bottom 20% of records,’ Ms Ganter said.
Ms Ganter said with drier conditions forecast, the risk of frost during winter, which is most common for southern and central Australia, was heightened for inland southern areas.
‘Even though average minimum and maximum temperatures are expected to be warmer than usual this winter, there will still be times of cold wintry conditions. This can increase the frost risk when there are still nights that are clear of cloud cover,’ she said.
In northern Australia, the dry season continues from May until September and much of the region experiences very low rainfall during this time as well as heightened bushfire risk.
Australia’s fire agencies have identified that while most of Australia has normal bushfire potential during winter, areas of above normal bushfire risk include a large area of the Northern Territory and pockets of New South Wales and north-western South Australia.
Fire potential depends on many factors including weather and climate, fuel abundance, recent fire history and firefighting resources available in the area.
The winter long-range forecast reflects several climate influences including:
the chance of El Niño forming in the Pacific Ocean
signs of a positive Indian Ocean Dipole (IOD) forming in winter
warmer than average ocean temperatures around Australia.
The Bureau remains at El Niño WATCH, which means around double the usual chance of an El Niño event.
While the models show it’s very likely that the tropical Pacific Ocean temperatures will reach El Niño levels during winter, a shift in the tropical atmosphere is also needed for us to declare an El Niño event.
Ms Ganter said any change to the El Niño WATCH status would not change the long-range forecast which is already trending towards warm and dry for most of Australia.
Autumn Summary fast facts:
- Australia’s autumn rainfall was about 10% below the 1961–1990 average.
Each state and territory had below average rainfall overall, except Western Australia with around 6% above average rainfall for autumn.
Australia had its second-driest May since national rainfall records began in 1900, with rainfall about 73% below the 1961–1990 average.
While Australia’s autumn rainfall was very much below average in some areas, Tropical Cyclone Ilsa brought above average rainfall to parts of the north, west and into South Australia.
Australia had its coolest autumn since 2012, with an average temperature equal to the 1961–1990 average for autumn.
Water storages along eastern Australia remain around 90%.
Most water storages in the north are close to full after the northern wet season.