Source: Bureau of Meteorology

For people in parts of Northern Rivers, Mid North Coast, South Coast, Southern Tablelands, North West Slopes and Plains, Riverina, Northern Tablelands, Lower Western and Snowy Mountains Forecast Districts.

Issued at 7:11 pm Sunday, 24 December 2023.

Severe thunderstorms continue to develop across the state.

Weather Situation: A surface and upper trough are providing support for thunderstorm activity in the east in a moist and unstable airmass. A developing low pressure system is leading to severe thunderstorms in the southwest near the Victorian border.

Severe thunderstorms are likely to produce damaging winds, large hailstones and heavy rainfall that may lead to flash flooding over the next several hours in parts of the Northern Rivers, Mid North Coast, North West Slopes and Plains, Riverina, Northern Tablelands and Lower Western districts. Locations which may be affected include Lismore, Armidale, Moree, Deniliquin, Hay and Dorrigo.

Severe thunderstorms are likely to produce heavy rainfall that may lead to flash flooding over the next several hours in parts of the South Coast, Southern Tablelands and Snowy Mountains districts. Locations which may be affected include Bega, Moruya Heads, Narooma, Merimbula and Araluen.

Severe thunderstorms are no longer occurring in the Metropolitan and Illawarra districts and the warning for these districts is CANCELLED.

Koolewong recorded 55mm in the 60 minutes to 12:30pm.

Little Bay recorded 56mm in the 60 minutes to 4:59pm.

The State Emergency Service advises that people should:
* Move your car under cover or away from trees.
* Secure or put away loose items around your house, yard and balcony.
* Keep at least 8 metres away from fallen power lines or objects that may be energised, such as fences.
* Report fallen power lines to either Ausgrid (131 388), Endeavour Energy (131 003), Essential Energy (132 080) or Evoenergy (131 093) as shown on your power bill.
* Trees that have been damaged by fire are likely to be more unstable and more likely to fall.
* Keep clear of creeks and storm drains.
* Don't walk, ride your bike or drive through flood water.
* If you are trapped by flash flooding, seek refuge in the highest available place and ring 000 if you need rescue.
* Be aware that run-off from rainfall in fire affected areas may behave differently and be more rapid. It may also contain debris such as ash, soil, trees and rocks.
* After bushfires, heavy rain and the loss of foliage can make the ground soft and heavy, leading to a greater chance of landslides.
* Unplug computers and appliances.
* Avoid using the phone during the storm.
* Stay indoors away from windows, and keep children and pets indoors as well.
* Stay vigilant and monitor conditions. Note that the landscape may have changed following bushfires.
* For emergency help in floods and storms, ring the SES (NSW and ACT) on 132 500.