Spring to date has delivered some cool nights, warm days and less rainfall than we want, so what's likely for the rest of the season and why?
So far, September nights have been much cooler than normal in the west and north.
At the same time, days have been warmer than average in the north and east, returning to their recent above average trend after a cool August this year was the first month since August 2017 with a below average maximum temperature for the state as a whole.
It's a familiar story to last year when September days were warmer than average in parts of the north, east and centre, but nights were lowest on record for the north-west.
While rainfall has been below average for most of the state, September 2019 is faring better than last year; September 2018 was the second-driest on record for Victoria.
August is normally the wettest month of the year for Victoria (73.77 millimetres) so we would typically expect a gradual reduction in monthly totals as we head towards our driest month, February (31.97mm).
And just like this time last year, long-range forecasts for October and November show below average rainfall is likely over Victoria.
The chances of below average rainfall are highest in the north and gradually reduce to the south.
Averaged over October to December, maximum temperatures are very likely to be higher than usual in the north while there is no strong push towards warmer or cooler than average nights for most of the state.
While temperatures warm up as we move towards summer, frost remains a risk.
Most of the state has the potential for frost in an average September, and the computer model expects cooler than average nights at the end of September/start of October.
What's driving our seasonal weather?
The positive Indian Ocean Dipole (IOD) is forecast to continue until the end of spring.
Typically, a positive IOD means warmer and drier conditions across large parts of Australia, but IOD events typically decay towards the end of the year, having little influence on Australian climate from December to April.
That means the positive IOD's contribution to the drier outlook should start to reduce in early summer.
Another factor is a forecast for a negative phase of the Southern Annular Mode (SAM) during October and November.
This is largely due to a sudden warming of the stratosphere over Antarctica.
A negative SAM in spring often brings drier than average conditions to parts of eastern mainland Australia.
