The Bureau of Meteorology has released its 2018 Winter Outlook, with warmer and drier than average conditions expected across large parts of the country.
The winter outlook follows one of Australia’s warmest autumns on record and its second-warmest summer on record. Southern mainland Australia has also had one of its driest autumns on record.
The outlook suggests winter rainfall is likely to be below average for New South Wales, South Australia, northern Victoria and western parts of Western Australia. The shift towards drier conditions is particularly strong for areas around the Murray Darling Basin and eastern NSW which have a 70-80 per cent chance of below average rainfall. Elsewhere around the country, the chances of exceeding average rainfall are roughly 50 per cent.
Daytime temperatures across much of the country are likely to be warmer than average, with the greatest chance (more than 80 per cent) in New South Wales, Victoria and Tasmania. Overnight temperatures are also expected to be above average across the country, except for parts of the tropical north.
Australia’s main climate drivers, El-Nino-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are currently in a neutral phase, meaning there is no strong shift in the outlook towards widespread wetter or drier conditions.
Bureau climatologist Jonathan Pollock said when ENSO and IOD are neutral, other climate drivers have a greater influence.
“We’re expecting warmer than normal temperatures in the Tasman Sea this winter and associated lower-than-normal air pressure. This would mean a weakening of westerly winds over southern Australia that normally draw cold fronts up from the Southern Ocean,” Mr Pollock said.
“As a result of this, we’re expecting to see below average winter rainfalls for western parts of Western Australia and for most of New South Wales extending across the border into southern Queensland and northern Victoria. For most other parts the chances of above or below average rainfall is roughly equal.”
Mr Pollock said snowfall would also be of particular interest as we head into winter.
“Snowfall is difficult to predict over long time frames but the dry outlook for June 2018 suggests a later than normal start for the snow season. However, when ENSO and IOD are neutral we have historically seen deeper-than-average snow cover by mid-season.”
A range of climate products and services are available on the Bureau’s website to help inform decision-makers and the general public.
The rainfall and temperature climate outlook maps show the likelihood, as a percentage, of experiencing wetter/drier and warmer/cooler than average weather for the upcoming three months.