The BOM's winter forecast says 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.

BOM 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 per cent of records," Ganter said.

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.

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 and warmer than average ocean temperatures around Australia.

The BOM remains at El Niño ‘WATCH' status, 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.

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.

The BOM winter forecast can be viewed here:  https://bit.ly/3Pc8ODp