The Bureau of Meteorology's Winter Outlook dampens hope of rain

Bureau climatologist Jonathan Pollock is reporting of the likelihood of below-average rainfall in inland NSW and warmer than usual daytime temperatures this winter.

Mr Pollock has acknowledged that “large parts of NSW have serious to severe rainfall deficiencies spanning a year or more”.

“..unfortunately, most of inland NSW looks set for a dry winter with more than 75 per cent chance of below-average rainfall,” he said. “And the odds are even drier for the beginning of winter in June.

“Compounding that, autumn 2018 is likely to be the warmest autumn on record for maximum temperatures and the daytime warmth is likely to continue into winter with chances greater than 80 per cent. However, for much of the interior, night-time temperatures at the beginning of winter in June, have a roughly equal chance of being warmer or cooler than average.”

Mr Pollock said autumn had been “very dry across the state”. “It’s likely to rank as one of the 10 driest autumns on record,” he said.

Australia's main climate drivers, El-Nino-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), are currently in a neutral phase, indicating “no strong shift in the outlook towards widespread wetter or drier conditions”.

Mr Pollock said when ENSO and IOD were neutral, other climate drivers had a greater influence."We're expecting warmer than normal temperatures in the Tasman Sea this winter and associated lower-than-normal air pressure,” he said. “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 NSW 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."