A strong storm has hit Sydney, knocking out power to thousands of homes.
Severe thunderstorms are pounding NSW's east coast with destructive winds, heavy rainfall and large hailstones causing blackouts for thousands of homes.
The Bureau of Meteorology warned multiple cells were converging on Sydney late on Saturday afternoon, and a particularly "dangerous thunderstorm" was encroaching on Newcastle.
The storms will cause heavy rainfall that may lead to flash flooding, destructive winds and giant hailstones over the next several hours.
Endeavour Energy is working to restore power to around 54,000 homes and businesses in Sydney's north west.
"As the storm has brought down trees across the region, residents are reminded to stay well clear of fallen powerlines," a spokesman said in a statement.
Ausgrid is also reporting blackouts through the Central Coast and Hunter Valley.
There is no clear timeline for when the power will be restored.
Parts of the city's train network have ground to a halt again with a power outage and debris on the track stopping trains between Parramatta and Granville.
The Northern Line is also experiencing power failures which have stopped lifts and Opal card systems.
Some trains were replaced by buses in peak hour on Friday afternoon during torrential rain and, on Thursday, similar storms caused flash flooding in parts of the city.