Weather warnings issued for NSW

A severe weather warning has been issued for the parts of NSW and the ACT with fears heavy rain and thunderstorms could cause flash flooding.

A trough is expected to move slowly through the South Coast, Southern Tablelands, Snowy Mountains and Australian Capital Territory regions through Thursday night and Friday morning, the Bureau of Meteorology (BOM) says.

"Localised heavy rain and thunderstorms may lead to flash flooding," the BOM's warning, issued on Thursday afternoon says.

"There is a 75 per cent chance of minor flooding as well as local flash flooding to develop along the Queanbeyan (and) Molonglo Rivers in the early hours of Friday morning."

A severe thunderstorm warning has also been issued for the Upper Western, Central West Slopes and Plains and Central Tablelands regions.

The BOM expects other warnings to be issued on Thursday night.