Oceans impact long-range outlook

Australia's major climate drivers—the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD)—are likely to remain neutral through winter. When ENSO and the IOD are neutral they typically have little, if any, largescale influence on Australian rainfall and temperature patterns.

But even with these big climate drivers doing little to push our weather one way or another, the next fortnight is likely to be wetter than average for large parts of south-eastern Australia, including Victoria.

For April, western Victoria could see above average rainfall.

The long-range outlook for April to June shows slightly increased chances of above average rainfall for western Victoria, while East Gippsland could see less rainfall than normal.

Chance of exceeding median rainfall for April to June

There are roughly equal chances that days will be warmer or cooler than average for April overall. However, the three-month April to June outlook indicates eastern Victoria is likely to have warmer days than usual.

Parts of northern Victoria are likely to have warmer than average April nights, and that expands to the whole State (and country) for April to June.

With our major climate drivers being neutral, there are other factors are influencing the outlook.

Typically in the autumn after a positive IOD (we had one of the strongest on record IOD events last year), warmer than average ocean temperatures in the tropical eastern Indian Ocean bring more northwest cloud-bands – those long lines of cloud that cross the country from northwest to southeast. This draws moisture from the tropics right down to Victoria. If this moisture meets a cold front or low-pressure system, it can trigger off good rainfall, resulting in wetter than average conditions for Australia's southeast.

Warmer than average oceans around the coastline are also likely contributing to the warmer than average outlook over Australia.

Australia's temperature and rainfall variability are also influenced by long term trends in our climate. Australia's climate has warmed by around 1.4 °C since 1910, and there has been a decline of around 11 per cent in April–October rainfall in the southeast of Australia since the late 1990s.

The Bureau of Meteorology's climate model includes the influence of climate change and natural climate drivers like ENSO, IOD, and the Southern Annular Mode in its outlooks.

Recent Weather Updates

  • Wettest autumn in decades | 29/05/2020  

    Most of Victoria has been wetter than average this autumn so far, and it is only parts of the far east that have been drier than usual.

  • Chance of a double whammy | 15/05/2020  

    The chance of a wetter than average winter is strengthening for parts of the State.

  • Wetter winter likely for the north | 24/04/2020  

    A wet start to 2020 means root zone soil moisture for this time of year is above average for most of Victoria except for parts of the southwest and East Gippsland.