There's been a substantial change in the outlook for rainfall across Australia this winter, with a reduction in the likelihood of above-average rain across much of the country.

The latest update from the Bureau of Meteorology's seasonal forecast model, ACCESS-S, has dramatically pared back the rainfall prospects for much of Australia this winter.

At the end of May, the seasonal model favoured above-average rain for most of Australia between June and August.

Image: Winter rainfall outlook based on the ACCESS-S model run in late-May.

The latest model run, which was released on Thursday, reduced the likelihood of above-average rain for most of the country and increased the prospect of below-average falls in the north and far southeast.

Image: Winter rainfall outlook based on the ACCESS-S model run at the beginning of June.

The shift in this season's rainfall outlook has been underpinned by changes in oceanic and atmospheric conditions to the west and south of Australia in recent weeks. Sea surface temperatures to the northwest of Australia have cooled down during the past three weeks, partially in response to a flurry of late-season tropical cyclone activity. We have also seen a positive phase of the Southern Annular Mode (SAM) emerge during the second half of May and persist into the beginning of June. Both of these features - relatively cool water northwest of Australia and a positive SAM - are known to limit rainfall in parts of Australia during winter.

It's worth pointing out that while the likelihood of above-average rainfall this winter has reduced, it hasn't gone completely. The outlook still favours wetter-than-usual weather in parts of western, southern and eastern Australia, particularly from July onwards.