Torrential rain has fallen on NSW, with some towns copping more than 60mm overnight.
Coastal areas received the bulk of the downpour while communities in the northwest also experienced a soaking, including Billyrimba where 60mm fell in 24 hours.
Bundella (32mm), Bulahdelah (32mm) and Kerewong (36mm) were also drenched.
But Sydney did not escape the drenching with 79mm falling on Picton, southwest of the city – much of that during a one hour period.
The Bureau of Meteorology issued a severe storm warning late on Monday night, saying heavy rainfall was expected.
More rain is forecast for Sydney during the morning but that will clear later in the day.
There’s a gale wind warning in place for the Illawarra and Batemans coasts. A strong wind warning has been issued for Sydney Enclosed Waters, the Macquarie, Hunter, Sydney and Eden coasts.
The onslaught of rain has also trickled down to the NSW-Victorian border.
While temperatures will dip in Melbourne with just a top of 19C in the capital on Tuesday before it warms up again on Wednesday.
BOM said heavy rain was forecast for the state’s north east, but the initial severe weather warning has been cancelled.
Meanwhile, residents on the Western Australian coast have also been warned to prepare for a possible cyclone.
“People from Mardie to Ningaloo, including Onslow and Exmouth, should prepare for heavy rain and gales with wind gusts up to 100km/hr,” BOM said.
“It‘s predicted to move offshore on Tuesday then rapidly intensify into a cyclone.”
As a result, heavy rainfall is expected along the Pilbara region.
Flood warnings have been issued for the Fitzroy River, De Grey River catchment, the West Kimberley District, the Sandy Desert and Pilbara catchments.
Earlier this week the weather bureau said parts of Queensland could see up to 50mm of rain over an eight day period, as Topical Cyclone Lucas moves away from the northern Queensland coast.
The storms in NSW are also likely to filter over the border, bringing plenty of rain to the sunny state.
Conditions will dry out later in the week.
A few showers are expected in Brisbane on Tuesday.