Vast parts of Australia warned to brace for heavy rain and floods as multiple weather events bear down
Large parts of the country have been warned to brace for “intense” rainfall, with multiple separate weather events bearing down.
Vast areas of the country have been warned to brace for drenching rain over the next few weeks as a series of significant weather events take hold.
Firstly, a strengthening polar vortex over Antarctica is colliding with higher pressure over Australia’s south, increasing rain across the eastern seaboard.
Secondly, warmer than usual ocean temperatures off the north and east have sparked record-high humidity in Sydney, with particularly sticky conditions felt in Brisbane.
That will bring with it high rainfall and storms across the next week.
And a “raging” monsoon across Australia’s north has multiple communities on high alert, with a “significant” risk of flooding.
Rainy and humid
Metrologist Dean Narramore said a moist onshore flow along the east coast will bring continued humid conditions and showers.
On Thursday, Sydney experienced it highest dewpoint on record, passing 26C – that is, the temperature at which the air reaches saturation with water.
That made the temperature feel four to five degrees higher than it was, about in the early 30s.
A typical January morning in Sydney will have a dewpoint of 17.
Humid and sticky conditions will persist throughout next week across New South Wales and Queensland, Mr Narramore said.
That will cause “high humidity, showers and storms along our east coast”.
Parts of the eastern seaboard are expected to receive up to 50mm of rain by midweek, with some areas facing more.
Chunks of the West Australian coast, particularly around Perth, can also expect “severe and intense” heatwave conditions next week.
The strengthening polar vortex should bring some relief in the former of a cool southerly, but the reprieve from the heat and humidity will be short-lived.
North battered again
At the same time, Australia’s north is in the midst of a monsoon trough and low pressure system, raising the possibility of a cyclone forming.
Miriam Bradley from the Bureau of Meteorology said the country’s tropical north should brace for monsoon conditions including “long periods of heavy rainfall, thunderstorms and cloudy skies”.
“We’ve already seen cloud building over recent days across the northeastern parts of the country, with showers and storms generating heavy falls,” Ms Bradley said.
Over the coming week, Weatherzone is forecasting widespread falls exceeding 100mm across the north, while some areas could surpass 300mm to 500mm.
“Unfortunately, this rain is falling in the same area that received flooding rain from Tropical Cyclone Jasper and an associated monsoon burst last month,” it reported.
Queensland’s north continues to mop up following severe weather in December, which sparked flooding, high winds, widespread power losses and significant damage.
The monsoon trough is extending across the Kimberley through the Top End and Gulf of Carpentaria and into the Queensland peninsula.
It may move as far south as Broome in Western Australia, Tenant Creek in the Northern Territory, and Townsville and Mackay in Queensland, Ms Bradley said.
Anticipated “severe” conditions will persist for days and there’s a risk of flash flooding in some parts.
“Squally winds and elevated sea levels are also possible, but rain and flooding are really the most dangerous risks that we have ahead of us,” she said.
The Bureau is also keeping an eye on a number of tropical lows that are developing alongside the monsoon trough over the weekend.
“If the conditions are right and the systems stay over water long enough, that may deepen into tropical cyclones.
“However, in this situation, the risk of that happening is only low, largely because they’re not staying over water long enough.”
Regardless, she said the Bureau expects heavy rainfall across vast parts of the north.
Originally published as Vast parts of Australia warned to brace for heavy rain and floods as multiple weather events bear down
