The La Nina fuelled sodden spring will ramp up in the coming days with huge downpours from the desert to the sea.
Forecasters have said “half the country” could see rain this week, much of it heavy, as moisture from a tropical cyclone merges with humidity over the east.
Downpours could occur from Cape York to Gippsland and from Broken Hill to Bondi Beach.
Thursday is shaping up to be the wettest day of the week. This week’s rain event, the latest in a long line of inclement weather, is a hallmark of the La Nina climate driver which was officially called today.
Sydney and Brisbane could see up to 50mm of rain for the rest of this week, Canberra between 50 and almost 100mm and for Melbourne 30mm. Some parts of South Australia could see over a month’s rainfall in just a few days.
“A very, very wet few days ahead for eastern and also central parts of Australia,” said Sky News Weather meteorologist Alison Osborne.
“At least 60 per cent of the country is expected to see rainfall”.
Cyclone and humidity fuelling rain
The Bureau of Meteorology’s Jonathan How said on Tuesday afternoon that two systems were driving the unsettled weather.
“To our northwest tropical cyclone Patty is pumping cloud and humidity into the centre of the continent.
“At the same time, a humid air mass has been sitting over the east. These two tropical air masses will combine to bring widespread falls.
“Multiple flood warnings are still in place for parts of the Lachlan, Namoi and Gwydir rivers,” added Mr How.
“Upcoming rain may worsen current flooding and an initial flood watch has also been issued to parts of South Australia, where heavy rain may cause overland flow and disruptions to transport.”
Only Western Australia and Tasmania may miss out on the worst of the conditions.
Adelaide may also dodge the rain. While 6mm could fall on Wednesday that will be about it for the rest of a partly sunny week that will see 22C highs and dawn minimums in the low teens.
But head north and that rain will be far heavier. Port Augusta is looking at up to 25mm on a stormy Wednesday as that rain band marches east.
Around 10mm of rain could fall on Melbourne on Wednesday followed by 15mm on Thursday and a few more showers to end the week. The band will be followed by chiller temperatures with a midweek high of 24C dipping to 18C on Friday.
The lows won’t be too cold though. Thursday’s high of 19C will be just 3C warmer than its dawn minimum of 16C.
Like in SA, the further north you go the wetter it’s likely to get. Wangaratta could see 20mm in the gauge on Wednesday and then 20-40mm on Thursday and up to 35mm on Friday. Echuca, Mildura, Wodonga and everywhere in between should expect some similarly wet and stormy days.
Canberra should see the rain arrive on Tuesday with around 10mm falling, then 20-35mm the next day and 25-45mm on Friday. A storm is possible on Thursday.
Temperatures will start off in the low twenties but by Saturday 16C will be the maximum with dawn starts below 10C by the weekend.
Most of NSW to see downpours
Sydney’s rain will likely peak on Friday with 20-35mm, Thursday will see 8-15mm and a shower or two on Wednesday is on the cards. There is a possibility of storms for all those days.
It will be relatively warm, with the mercury heading in to the mid-twenties and lows pushing 20C. But there will be a dip in the warmth as the rain passes with a 20C high on Saturday.
Just about all of New South Wales could see rain, some of it heavy in places.
Broken Hill will get up to 55mm of rain this week; Merimbula 70mm; Orange 80mm and a similar level in Ballina.
There will be showers in Brisbane for the rest of the week with a peak of 15-30mm on a stormy Friday. Between 30mm-80mm of rain is possible in total in the coming days. Temperatures should remain around 27C for the week with minimums in the low twenties.
It’ll be wet in Rockhampton and Townsville, with around 60mm falling between now and Saturday.
Tasmania, WA to escape the worst
Tasmania may get some showers but much of the rain band won’t get that far south. A few drops of rain until Thursday and then mostly cloudy and dry. Expect a high in Hobart of 22C on Wednesday but the colder weather will come through, with a high of just 14C on Friday. Lows will be around 8C by the weekend.
Afternoon storms in Darwin could bring some rain this week, the heaviest is likely to be on Saturday with 5-15mm falling. A hot 35C is predicted for the Top End.
Following the rain on Tuesday, Alice Springs should remain mainly dry for the rest of the week.
Settled and sunny and only getting hotter in Perth with a repeating pattern of blue skies and no rain. Temperatures will head towards 34C on Saturday reducing to 20C overnight.