Grim weather warning for millions of Aussies: 'Flooding is possible'

The wild weather is set to continue for millions of residents on the east coast, as heavy showers show no sign of letting up.

Sydney is expected to cop up to 60mm of rain on Sunday afternoon and into the evening as heavy rains, which have plagued the eastern states this week, continue.

Overnight about 130mm to 150mm fell in the Jarvis Bay area, with the Bureau of Meteorology predicting the rainfall has begun to move north.

The wet weather is expected to continue into Monday, easing midweek, before returning next weekend - with up to 150mm possible in the next seven days.

Over the past seven days, eastern New South Wales and coastal Queensland have been getting an absolute soaking with up to 100mm of rain recorded over a vast swathe of territory.

Apart from showers in WA's southwest and in southern Queensland, much of the rest of the country is expected to remain fine and dry on Sunday.

Bureau of Meteorology senior meteorologist Dean Narramore, said areas south of Sydney have copped the heaviest falls so far, but the system has begun to move north.

'That heavy rainfall in the Illawarra is going to start moving north today so we're going to start seeing those heavy showers around Sydney this morning,' he told Nine's the Today show. .

'We're looking at a pretty wet late morning and especially afternoon and evening with widespread 30 to 50mm likely.'

Severe weather alerts have been issued for possible flash flooding in parts of the Illawarra district and thunderstorms north of Wollongong and east of Dubbo on Sunday evening.

'Flash flooding is possible about parts of the Illawarra district from early SUnday morning until late Sunday evening,' The Bureau said.

'Six-hourly rainfall totals between 100 and 140mm, with isolated falls in excess of 150mm, are possible.'

To the north, Brisbane is forecast to have cloudy weather with a slight chance of a shower on Sunday and Monday.

In Melbourne, not a drop of rain was forecast into next week, with the Windy City set to reach a high of just 20C..

Adelaide was likewise set it's dry and sunny weekend with a high on Sunday of 23C, while Canberra's light rainfall becoming less likely into the evening.

Dry but cloudy weather was forecast across the other capitals, including in Darwin, Hobart, and Perth, which was smattered by rain during the week.