A severe weather warning has been issued for parts of the Southern Highlands.
The Bureau of Meteorology is forecasting damaging winds and heavy rainfall.
The conditions are being caused by a complex low pressure system moving across the Great Australian Bight
An associated trough and cold front are also causing vigorous northwesterly winds across southeast NSW.
The State Emergency Service has the following advice:
* Move vehicles under cover or away from trees.
* Secure or put away loose items around your house, yard and balcony.
* Keep at least 8 metres away from fallen power lines or objects that may be energised, such as fences.
* Trees that have been damaged by fire are likely to be more unstable and more likely to fall.
* Report fallen power lines to either Ausgrid (131 388), Endeavour Energy (131 003), Essential Energy (132 080) or Evoenergy (131 093) as shown on your power bill.
* Don't drive, ride or walk through flood water.
* Keep clear of creeks and storm drains.
* If you are trapped by flash flooding, seek refuge in the highest available place and ring 000 if you need rescue.
* Be aware that run-off from rainfall in fire affected areas may behave differently and be more rapid. It may also contain debris such as ash, soil, trees and rocks.
* After bushfires, heavy rain and the loss of foliage can make the ground soft and heavy, leading to a greater chance of landslides.
* Stay vigilant and monitor conditions. Note that the landscape may have changed following bushfires.
* For emergency help in floods and storms, ring your local SES Unit on 132 500.
Image: Bureau of Meteorology