Eastern Australian residents should brace for rain, storms, hail and flooding as La Nina continues to batter the country's east coast for a second week.
The Bureau of Meteorology's Jackson Browne said northern NSW and Queensland were of particular concern during his severe weather update on Monday afternoon.
"Rainfall broadens inland and consolidates early Tuesday as our upper trough looms overhead. Cumulative falls of 50 to 100mm are likely out till Wednesday, with lesser amounts further west," Mr Browne said.
"Severe thunderstorms are expected to develop, bringing the risk of heavy rainfall, large hail and damaging winds."
The meteorologist said moisture in the north of the country would team up with a trough from southern Australia to create wet conditions on the east coast from Tuesday and onward.
"The water vapour loop shows areas of rich tropical moisture in green, lying and wait over eastern Australia," Mr Browne said.
"An upper level trough over southern Australia stands up and moves east during today and Tuesday, greatly aiding the development of widespread rain and storms."
There is currently a major flood warning for the lower Macintyre River and flooding warning for the Weir River in both NSW and Queensland.
There are also minor to major flood warnings for the Lachlan, Macquarie and Namoi rivers in NSW.
A number of minor, moderate or final flood warnings are also in place for Victoria, the ACT, NSW and Queensland, which can be viewed on the BoM website.
Mr Browne said "hit and miss storms will be an unwelcome addition to the widespread rainfall over these sodden or flooded areas".
"Dams are full and many catchments are either flooded or saturated, so any further rain and thunderstorm activity will lead to renewed river rises and prolonged flood peaks. Flood watches have also been issued in anticipation of the upcoming rainfall," he said.
"Residents living on or near flooded rivers and creeks, especially in parts of northern New South Wales and Queensland, need to remain vigilant. Please stay across the latest forecasts of warnings as many rivers are likely to experience flooding in the coming days."