Severe thunderstorms are set to continue soaking much of NSW after a heavy drenching overnight.
Tuesday's storms may lead to flash flooding for people in the state's northwest and central areas, the Hunter, Central Coast and Sydney, particularly in the Blue Mountains regions, according to the Bureau of Meteorlogy.
It's issued a severe thunderstorm warning for heavy rainfall and damaging winds for those areas, with Armidale, Orange, Tamworth, Moree, Dubbo and Parkes expected to be the worst hit.
The forecast comes after the wild weather dumped hailstones the size of golf-balls to some parts of the state's central west late on Monday, as a low-pressure system made its way towards Queensland.
Dubbo bore the brunt of the storm, with more than 69mm of rain dumped in the area.
The State Emergency Service said it received 150 calls for help statewide, while several properties, including the Charles Sturt University campus, were shut down due to water damage.
The storm cell is expected to bring up to 40mm of rain to parts of Sydney on Tuesday.
"While there is a risk of a super cell thunderstorm, that decreases overnight," bureau forecaster Rebecca Kamitakahara told AAP.
"They are still predicted to bring destructive winds however," Ms Kamitakahara said, adding that the central and north-west slops and plains are most at risk.
The SES has warned people to prepare for the stormy conditions by clearing drain pipes and gutters, keeping at least eight metres away from fallen power lines, unplugging computers and appliances during the storm and staying indoors.
The State Emergency Service advises that people should:
* Keep clear of creeks and storm drains.
* Don't walk, ride your bike or drive through flood water.
* If you are trapped by flash flooding, seek refuge in the highest available place and ring 000 if you need rescue.
* Unplug computers and appliances.
* Avoid using the phone during the storm.
* Stay indoors away from windows, and keep children and pets indoors as well.
* For emergency help in floods and storms, ring the SES (NSW and ACT) on 132 500.