Weather: Millions in firing line as majority of Australia cops heavy rain, storms, flooding

Millions of Australians will be in the firing line for a drenching as a band of rain, flash flooding and storms washes over almost every state and territory this week.

A low-pressure system is currently passing over southeastern Australia, sparking warnings of thunderstorms and flash flooding across the country.

Bureau of Meteorology senior meteorologist David Crock told NewsWire said the country was in for an “interesting week”.

“It’s going to be an interesting week or an interesting few days,” he said.

The low-pressure system is driving heavy rainfall and “plenty of storms” throughout far east Western Australia and extending toward southern Northern Territory.

“That low pressure system is really going to be the main story for the next probably four days,” he said.

On Monday, the band of rain and thunderstorms are set to crawl to South Australia, where it will drench most of the state including the Eyre Peninsula, York Peninsula and the Adelaide Hills.

“That low could see some rainfall totals of … 20 to 40 millimetres, and perhaps a few higher totals accumulate over the course for the second half of (Monday) and into Tuesday morning,” Mr Crock said.

The rain will drench an already soaked region of South Australia, he said.

“Many of those areas are quite wet already following a couple of good rain events in recent weeks, particularly in the Adelaide Hills about 10 days ago or so,” he told NewsWire.

“Even if the rain numbers aren’t that high, there could be some substantial impacts in terms of creeks running and flash flooding.”

In addition to the heavy rainfall, the Bureau of Meteorology warned of strong winds on Monday in the Far West Coast, Upper West Coast, Lower West Coast, the Central Coast and Spencer Gulf.

It’s not just South Australia set to cop a soaking this week.

The low pressure system will crawl eastwards on Tuesday, settling itself over the southern and western parts of NSW and northeast Victoria.

“It’ll bring quite heavy rain to many areas, particularly northeastern Victoria and … as far as southern New South Wales, into the hills there,” Mr Crock said.

“Some of those areas could see sort of 40 to 60 millimetres of rain on Tuesday, again with some higher totals possible there and those catchments, particularly (in) northern Victoria, (are) really wet at the moment.”

The bureau has issued flood warnings for the Kiewa, Loddon and Avoca catchments.

An initial flood warning is also in place for parts of North West, Central and North East Victoria, with river levels forecast to rise between Monday and Wednesday.

Impacted rivers include the Upper Murray and Mitta Mitta Rivers, Kiewa River, Ovens River, King River, Broken River, Seven and Castle Creeks, Goulburn River Eildon to Seymour and downstream of Seymour, Loddon River and Avoca River.

“(We’re) likely to see more flooding in some of those northern Victorian catchments from … Tuesday onwards,” he said.

The system will then move south towards the Tasman on Wednesday. However, before it vanishes, the rain will stretch upwards into eastern NSW and southern Queensland.

“Those areas are much drier this winter so far, so they’ll be happy to see more rain,” he said.

“(A) big system, bit of thunderstorms and flooding. But then also good news for some who need more winter rain.”

Monday’s weather forecast across the country

Looking ahead to Monday, residents in Brisbane can expect a partly cloudy day with a medium chance of showers and a top of 23C.

It will be a bright and sunny day on Monday for those in Sydney, with light winds and a top of 22C.

Canberra will be foggy and frosty in the morning, but the skies will clear in the afternoon with the mercury reaching a maximum of 19C.

Residents in Melbourne can expect a partly cloudy day with a medium chance of showers and a maximum temperature of 18C.

There will be cloudy skies in Hobart on Monday with a slight chance of a shower and light winds, reaching a top of 17C.

Adelaide will see cloudy skies and a very high chance of rain, with a maximum temperature of 16C.

Meanwhile, it will be mostly sunny in Perth and a top of 20C.

Monday will be cloudy in Darwin with a slight chance of a shower, reaching a maximum of 31C.