A SERIES of cold fronts brought showers to south-eastern Australia last week.
Isolated spots in Victoria's alps recorded weekly rainfall totals exceeding 50 mm (in the week ending on August 24), with smaller totals across southern and eastern Victoria and only light rainfall for the north-west.
With only a week to go, winter 2021 rainfall has been close to average for most of Victoria, with areas of above average in the south-west and south-east and an area of below average around Melbourne.
]Although the rainfall has been close to average for most, it is still looking like Victoria's wettest winter since 2016.
It has also been warmer than average this winter with mean temperatures likely to be in the warmest decile (highest 10-percent of records) for many areas.
Much of inland New South Wales and south-east South Australia has been wetter than average this winter.
Hume Dam water storage is 90.6 per cent full, 34.4pc higher than the same time last year and Lake Dartmouth storage is 72.1pc full. The Murray-Darling Basin Authority released close to 19 gigalitres from Hume Dam from August 7-15 to maintain airspace in the dam.
Spring (September to November) rainfall is expected to be above median for most of Victoria. The highest chances of above median rainfall are in the north (greater than 80pc chance), tending to a neutral outlook (close to 50pc chance) for parts of the coast. Spring days are likely to be warmer than median for southern Victoria, while nights are very likely to be warmer than average across the state.
The current negative Indian Ocean Dipole (IOD) event is likely to persist during spring.
A negative IOD event increases the chances of above average winter-spring rainfall for much of southern and eastern Australia. The 2021 negative IOD event and its impacts are weaker than the last event in 2016.
In the Pacific, the El Nino-Southern Oscillation (ENSO) is currently neutral with no strong indication that La Nina (or El Nino) will develop in the coming months.
Most models forecast tropical Pacific sea surface temperatures to cool over the coming months but remain ENSO neutral. The cooler Pacific sea surface temperature pattern may be contributing to the wetter than average outlook for parts of the country.
Australia's climate has warmed by about 1.44°C over the period 1910-2019. In recent decades, southern Australia has seen a general reduction of 10-20pc in cool season (April-October) rainfall.
