Sydney, Melbourne, Brisbane, Canberra weather: Heavy rain about to strike

Parts of Australia's east coast are set to be lashed with heavy rain over the next couple of days - with some areas having already seen three times the average rainfall for November.

Sydney, Melbourne, Canberra and Brisbane are all in the firing line for extremely wet conditions over Tuesday and Wednesday.

Between 10mm to 30mm of rain is forecast for Sydney on Tuesday, with the harbour city to be hit with up to 35mm on Wednesday.

The nation's capital will also be hammered with rain and potentially thunderstorms, with up to 30mm of rain forecasted for Tuesday while 25mm to 60mm of rain is possible for Wednesday.

Melbourne won't be escaping the bad weather, with 10 to 25mm of rain expected to fall on Wednesday.

Brisbane residents can also expect a drenching, with between 2mm to 20mm forecast for Tuesday, with storms also possible on Wednesday.

By Thursday the Sunshine State will be in the clear with sunny conditions and temperatures in the low 30s expected for the rest of the week.

In NSW's south-west, a severe thunderstorm warning has been issued for Wentworth and Menindee, with damaging winds also likely to wreak havoc.

The miserable conditions come despite El Niño being declared in Australia - a climate pattern that typically brings below average rainfall and higher than average day-time temperatures.

While September and October were very dry months for Australia, some states have seen their wettest Novembers on record during El Niño this year.

'Some areas in Queensland, NSW, the NT, SA and WA have already collected more than three times their average November rainfall and there is more wet weather in store for the final days of the month,' Weatherzone's Ben Domensino said.

The meteorologist said the reason for the wet conditions is because El Niño isn't the only factor influencing Australia's weather.

Mr Domensino said individual weather systems are controlled by jet streams of very fast-moving air.

'There are two jet streams in each hemisphere, and they mostly flow from west to east. The strength and shape of the jet streams affects the movement of high and low pressure systems near the Earth's surface,' he said.

He said that a 'meridional jet stream' was lingering over Australia which was causing adverse weather over a prolonged period of time.

That jet stream 'will produce a lengthy spell of rain and thunderstorms' over Australia's east and southeast this week.

Adelaide was hammered with storms on Monday night, causing some flight delays and leaving thousands without power.

By 9am on Tuesday, more than 33mm had been recorded in the CBD and 35.8mm at Adelaide Airport.

Tuesday marked the wettest day in November at the airport in 59 years, and in the CBD it was the wettest day this month in 18 years. 

The SES responded to 170 calls for help across South Australia until 9am on Tuesday. 

Severe thunderstorm warnings remain in place around Adelaide on Tuesday. 

Meanwhile on the other side of the country, those living in Perth can expect a dry and sunny week ahead with tops of 33C on Friday.

Hobart will see some chilly temperatures with tops of 17C forecast for Wednesday and Thursday, with rain also possible on these days.

Darwin will linger around the low 30Cs with storms also on the horizon.