Widespread rain over the coming week will be welcomed by NSW farmers but the heaviest falls will be along the coast rather than where it's needed most.
The highest totals are expected in the north and mid north coast regions on Thursday and Friday before the system moves south into the Hunter and Sydney on the weekend.
Significant rain is then likely to fall around the ACT and south coast into Monday.
Bureau of Meteorology modelling suggests 200 millimetres will fall on the north coast by Saturday evening with higher cumulative totals in southern NSW over Sunday and Monday.
Already on Wednesday upwards of 20mm had fallen near Dubbo and Burke although the majority of western NSW's rainfall is expected on Saturday.
Bureau climatologist Blair Trewin says the rain is unlikely to have a huge impact due to the deep impact of the drought.
"It's going to be a significant rainfall event across the state but the extreme west will not pick up too much," he told AAP.
"Most western rainfall activity will be concentrated around the northern inland area, particularly along the NSW-Queensland border.
"The (rainfall) deficits are very big so it certainly won't go very far but it's better to have it than not have it."
Mr Trewin said three years of dry cool seasons had resulted in drier waterways and low water storage levels.
"Evaporation during the cooler season is lower and it looks like this upcoming season outlook is going to be slightly towards the drier side again which will not be good for the sustainability of the land," he said.
"Dryland crops could be decent but a dam, for example, would need a lot more rain to fill."
Canola, wheat and barley farmer Neil Westcott says the past three years have been a challenge for everyone in his community around Parkes, with sporadic heavy rain often causing more damage than good.
"The ground is so bare, the water just runs off it like a dinner plate," he said.
"It seems to fall less often and be more severe which has damaged fences and caused erosion."
Mr Westcott said Parkes has experienced some good rain this year but just out of town on his 2500-hectare property he's received about 20 millimeters in 2020.
"It's very sporadic, just recently there was flash flooding 15 minutes north and we missed all of it," he said.
"We're croppers so we don't need to fill dams as much as livestock farmers but we need moisture in the soil and we just haven't had that.
"Last year, two-thirds of my crops were total failures and the year before that it was probably worse."
Mr Westcott is hopeful the "laws of probability" are in his favour this year. He's optimistic of 25 to 50mm over the next week.
Australian Associated Press