The chances of experiencing a wetter than average winter are strengthening for parts of the State.
This reflects the rainfall outlook for most of Australia during the winter months of June to August.
Forecasts are showing most of the country is very likely to have a wetter than average season.
The chances of this are strong - at more than 80 per cent - and stretch all the way from north west of Western Australia, across and down to central Victoria.
But the wet signal does not push over the Divide.
Parts of East Gippsland and the New South Wales coast only have a 50:50 chance of a wetter than average winter.
Daytime temperatures are likely to be cooler than average in north west Victoria and warmer than average in East Gippsland during winter.
There are high chances - of more than 80 per cent - that nighttime temperatures will be warmer than average across the north.
But there is no strong push towards higher or lower minimum nighttime temperatures in the far south.
Before winter, most of Victoria has a roughly equal chance of being wetter or drier than average for the second half of May.
The tropical Pacific and Indian Oceans can strongly influence south eastern Australia's seasonal weather.
Both the El Nino-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) are currently neutral.
But all of the international climate computer models surveyed by the Bureau of Meteorology suggest there is the possibility of a negative IOD developing in the Indian Ocean from the middle of winter.
Some models also suggest a La Nina in the tropical Pacific Ocean is possible in early-to-mid spring.
A negative IOD typically brings above average winter-spring rainfall to the State.
When ENSO is neutral, it has little influence on Australian climatic conditions.
La Nina typically means above average winter-spring rainfall for most of Victoria - with less influence over Gippsland.
Overall, the international climate computer models favour a negative IOD developing.
But it is not guaranteed, as they all show either a neutral IOD or negative IOD are possible.
Also, the accuracy of IOD and ENSO forecasts for winter-spring are lower during autumn and improve during winter.
This means that current ENSO and IOD forecasts should be used with some caution.
Visit www.bom.gov.au for weather outlooks.
- Jonathan Pollock is a BoM Climatologist
