Sydney, Brisbane, Melbourne weather: When rain will end as deluge strikes big cities

A week-long rain bomb has hit Australia as a wet weather system makes it way across the country.

Rainfall graphs show much of Australia's Top End and almost the entire 4,000km stretch of the east coast forecasted to cop a soaking every day until next Wednesday and beyond.

Thunderstorms continue to smash northern Australia and the east coast as they move towards the southern states, bringing damaging winds, hail and flash flooding.

It will be a wet weekend for most capital cities ahead of even more rain next week.

Melbourne will receive up to 9mm and a possible thunderstorm forecast for Saturday followed by an additional 9mm on Sunday. 

The sun is not expected to return in Melbourne till Thursday. 

Adelaide received a 13mm bucketing on Thursday night which arrived 12 hours earlier than expected. It was the city of churches' first double-digit fall in two months.

More rain is on the way for Adelaide's with 10mm on Friday and 8mm on Saturday but should clear up in time for Sunday's Adelaide 500 Supercars race.

Sydneysiders will need to keep their umbrellas handy for the next week with up to 100 forecast after heavens opened on Thursday night.

Up to 5m will fall in Sydney on Friday followed by another 10mm on Saturday ahead of a 25mm deluge next Tuesday. 

It is not expected to clear up in Sydney until Friday.  

Brisbane will also see rain, especially early next week, reaching 30mm to 60mm over seven days

On the other side of the country, Western Australia's record breaking heatwave will extend into the weekend where Perth's maximum temperatures won't drop below 30C until Tuesday. 

The prolonged extreme weather is due to several troughs triggering thunderstorms and rain across WA's west and north, the Northern Territory, Queensland which have since extended to NSW and the southern states.

The rain will also move across the Bass Strait into Tasmania with 15mm forecast for Hobart on Sunday.

'It's not unusual but it is a significant rain and thunderstorm outbreak,' Weatherzone meteorologist Yoska Hernandez told Daily Mail Australia.

'Most capital cities will see rain this weekend.

'The widespread precipitation we've seen this week will extended into the weekend and into mid-next week.

'It's due to successive upper level troughs extending across WA and across the Top End which have extended into eastern Australia, which is why we've seen storms every day this week.'

'Rain and thunderstorms will continue each day until Wednesday next week.'

Inland region, Queensland and NSW, north-western Victoria, parts of south-east and south-eastern Australia will be in the firing line of heavy rainfall and thunderstorms on Friday, bringing damaging hail and damaging winds

Widespread falls of 30-60mm is expected across much of northern and eastern Australia with some regions getting as much as 100mm or even double.

'As we move into tomorrow, it will edge more towards the coast, the areas more likely to see the severe weather are inland and southern parts of Queensland, down through central and south-eastern NSW into eastern and southern Victoria,' Bureau of Meteorology's Christie Johnson said.

'Then, as we move into the start of next week, it contracts towards the east coast, maybe some of the coastal parts of NSW, south-eastern parts of Queensland, eastern part of Victoria.'

Tuesday looks to be the wettest day for Queensland and northern NSW with the heavier rain moving further south over Sydney by next Wednesday. 

'We will then see a system develop quite similar to this one, rinse and repeat, that will start to bring the risk back into more central parts of Australia,' Ms Johnson said.

The weather bureau has reminded those in the firing line that thunderstorms can generate damaging or destructive winds which can destroy fences and outdoor furniture, as well as bring down power wines and cause power outages

The severe storms may generate large or giant-sized hail which can cause injury and damage anything outdoors, including cars.