New South Wales is bracing for two wet weather systems moving across the state over the coming week as emergency services deploy extra resources to areas of concern.
Western and central parts of the state, where there has already been months of ongoing major flooding, are expected to bear the brunt of both weather systems.
Bureau of Meteorology meteorologist Gabrielle Woodhouse said the first of the "very significant" weather systems was developing over inland NSW today.
A severe weather warning for heavy rainfall has been issued for the Riverina, Lower Western, Upper Western and parts of the Central West Slopes and Plains.
"This system is expected to move further east and bring moderate to heavy rainfall, quite widespread, to inland areas of NSW today and tomorrow and weaken as it moves toward the south-east on Thursday," Ms Woodhouse said.
She said a second system was expected to quickly follow, bringing more rain, particularly around the western slopes and ranges from Friday before spreading toward the coast on Saturday and Sunday, where a low pressure system may develop.
A month's worth of rain is set to be dumped on parts of the state in just a few days, with the weather bureau predicting widespread falls of 20-30mm with as much as 50-80mm in some areas.
"It's fairly significant to get a month's worth of rain in the space of a day or two ... that is falling on the backdrop of a really, really wet state at the moment," Ms Woodhouse said.
"We will start to see more of a flash flooding risk as well as a riverine flood risk over the coming days."
A minor to major flood warning is currently in place for the Macquarie, Lachlan, Culgoa, Birrie and Bokhara Rivers.
Minor to moderate flood warnings are also in place for the Namoi, Bogan, Murray, Edward, Barwon and Darling Rivers.
Ms Woodhouse said northern parts of the coast were less likely to see heavier rainfall totals, but the bureau was closely monitoring both weather systems.
Emergency services rally resources
NSW State Emergency Service (SES) commissioner Carlene York said it was critical for residents and holiday-makers in areas of concern to heed warnings and make safety preparations.
"What we're facing at the moment is these continuous rolling weather events, the ground is saturated, the dams are full to overflowing and the rivers are in various states of flood," Ms York said.
She said the SES had deployed additional resources to the areas of concern, including additional vehicles, boats and aviation assets, and local units were giving out free sandbags.
Ms York urged people to check the SES's new online warning system HazardWatch for live updates and advice, which were "designed to give you better, clearer messages ... and will let you know what the risks are".
People have again been reminded not to drive through floodwaters, with a "lucky" escape for four people who were rescued from a vehicle in Griffith last night.
"They attempted to get through the flooded roads and it led to their car being inundated with floodwaters and our members having to go out and rescue those people," Ms York said.
She said the SES had conducted more than 100 flood rescues in the past month, with a total of more than 2,200 requests for assistance in September.
