The SES has advised people to stay indoors and move cars under cover.
Weather conditions across NSW have caused significant public transport delays as severe thunderstorms sweep across the state.
The Bureau of Meteorology warned severe thunderstorms were likely to produce damaging winds and large hailstones over the next several hours.
Light rail services between Carlingford and Rosehill are not running due to fallen overhead wires near Carlingford.
Passengers are being advised to make alternative travel arrangements.
Meanwhile, power supply issues at various locations are causing delays on the T1 North Shore & Western Line, T5 Cumberland Line and Blue Mountains Line.
Trains around the Richmond, Penrith and Blacktown areas may also stop on platforms or between stations for longer than normal, and stops may change at short notice due to the conditions.
The delays come as dangerous thunderstorms developed across Hunter and parts of the Mid North Coast, Central Tablelands, North West Slopes and Plains, Central West Slopes and Plains and Upper Western Forecast District.
The Hunter Region and parts of the Mid North Coast, Central Tablelands, North West Slopes and Plains, Central West Slopes and Plains and Upper Western districts are all set to be affected by the conditions.
Locations which may be affected include Newcastle, Tamworth, Bourke, Scone, Walgett and Coonabarabran.
The Bureau said at 12.45pm the systems were likely to create dangerous weather conditions near Richmond, Colo Heights, St Marys and the Wollemi National Park, west of Putty.
The storms were moving eastward, some across much of metropolitan Sydney.
However, severe thunderstorms are no longer expected to hit this region and warnings for the metropolitan district have been cancelled.
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They were initially forecast to affect Hornsby, Parramatta and Windsor by 1.15pm and Mona Vale, Cessnock and Branxton by 1.45pm.
The NSW State Emergency Service (SES) has advised people to stay indoors and move cars under cover and away from trees.
More to come.

