A new band of rain is headed for flood-hit NSW and is expected to push rainfall totals in some places to one metre in the space of just a week.
The Bureau of Meteorology says eastern NSW is in for a double whammy.
A new band of rain moving down from the Kimberley in Western Australia will push through central Australia on Sunday.
On Monday it will pass over outback southern Queensland into northern NSW, where it will link up with the slow moving coastal trough that's already caused widespread flooding on the east coast.
BOM meteorologist Jonathan How says it's not yet clear where the rain band will dump the heaviest falls because they'll be generated by hard-to-predict storm activity.
But he says eastern NSW is definitely in the firing line, when the band and the trough come together.
"That's when we'll see a very large burst of rain, across eastern NSW, dipping into northeastern Victoria, and southeast Queensland from Monday night, into Tuesday," he told AAP.
The first dry day for NSW is not expected until Wednesday.
Mr How said some NSW locations, particularly around the Port Macquarie area, had already recorded 500-600mm of rain in the past 48 hours or so.
"By Monday or Tuesday, it's not unreasonable that some places will possibly poking one metre of rain for the whole event," he said of the rain which began in earnest on Wednesday.
