Sydney has been hit by intense rain this morning, with flash flooding around the city.
Before 8am, 17mm fell in just 10 minutes in the city centre, Weatherzone head meteorologist Alex Zadnik said.
Mr Zadnik said that, outside tropical areas, flash flooding was generally expected if 15mm or more fell in one hour, so this morning's rainfall was particularly intense.
"We've already got some minor flooding of low lying roads and the like and it's likely to become worse through today and tomorrow," Mr Zadnik said.
There were long delays on Syd Einfeld Drive, Bondi Junction, due to flooding about 8.30am, the Transport Management Centre said.
Water was flowing over the road, delaying heavy citybound traffic, and motorists were urged to avoid the area.
Citybound commuters on the M4 were also being delayed by an accident at Eastern Creek.
Southbound lanes of the Eastern Distributor exit at Anzac Parade, near Moore Park, were closed about 7.45am due to flooding.
Herald photographer Nick Moir took pictures of water flowing over the road at Baronga Avenue, Queens Park, in the eastern suburbs.
A spokeswoman at the Transport Management Centre said there were some scattered delays on the train network this morning, but there were no major hold ups caused by the rain.
Mr Zadnik said there was also heavy rain near Sydney Airport, with 5mm falling in 40 minutes.
"The expectation is for the rain to become heavier through today, especially through the afternoon and night time.
"Heavier falls are likely to persist through Wednesday as well."
Sydney's average rainfall for April is 126mm, which is likely to be broken by falls this week.
"It's fairly likely that over the next three to four days we'll see that monthly average achieved," Mr Zadnik said.
"We should see over 100mm in the next three days, with the bulk of that falling today and tomorrow."
The wet weather was being caused by a deepening low pressure trough on the east coast, causing an increase in cloud and rainfall.
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