Thunderstorms easing across NSW

Thunderstorms that lashed parts of NSW on Sunday evening are easing, the Bureau of Meteorology says.

Parts of the state, especially in the Illawarra and on the south coast, copped a drenching late on Sunday, and a severe thunderstorm warning is still in place for large swathes of NSW.

The warning is current for the Central Tablelands, South West Slopes and parts of the Hunter, Metropolitan, Illawarra, Southern Tablelands, North West Slopes and Plains and Central West Slopes and Plains Forecast Districts, BoM advises.

It says storms could affect locations including Penrith, Orange, Mudgee, Bathurst, Katoomba and Yass.

However, BoM forecaster Chris Webb told AAP the storms "were in a process of easing".

"There is only the possibility of isolated marginally severe storms at the moment," he said.

"It's all getting pretty marginal now."

He said there was still a risk severe storms could hit the Blue Mountains, central west or south west slopes.

BoM says if severe thunderstorms develop in the Sydney, Newcastle or Wollongong areas, a more detailed warning will be issued.

A severe thunderstorms warning for the South Coast, Snowy Mountains, Australian Capital Territory and Northern Tablelands districts has been cancelled.