The Bureau of Meteorology has issued a severe thunderstorm warning for the Hunter, South Coast, Central Tablelands, Southern Tablelands, Central West Slopes and Plains, South West Slopes, Snowy Mountains, Australian Capital Territory and parts of the Mid North Coast, Metropolitan, Illawarra, North West Slopes and Plains, Riverina and Upper Western forecast districts.
Severe thunderstorms are likely to produce heavy rainfall that may lead to flash flooding in the warning area in the next few hours.
Locations which may be affected include Newcastle, Gosford, Orange, Canberra, Goulburn, Dubbo, Wagga Wagga, Albury and Bourke.
The next warning is due to be issued by 5:20pm.