Source: Bureau of Meteorology

For people in parts of Blue Mountains/Hawkesbury, Maitland/Cessnock, Greater Newcastle, Gosford/Wyong, Wollondilly/Wingecarribee and Greater Wollongong areas.

Issued at 8:20 pm Monday, 25 December 2023.

POSSIBLE GIANT HAIL IN A SEVERE THUNDERSTORM NEAR BOWRAL.

The Bureau of Meteorology warns that, at 8:20 pm, a VERY DANGEROUS THUNDERSTORM likely to produce large, possibly giant hailstones, damaging winds and heavy rainfall that may lead to flash flooding was detected. The thunderstorm is moving towards the southeast. The severe thunderstorm is forecast to affect Bowral, Hill Top and the area just east of Bowral by 8:50 pm and Lake Avon and Lake Nepean by 9:20 pm.

Other severe thunderstorms likely to produce damaging winds, large hailstones and heavy rainfall that may lead to flash flooding were detected near the Bathurst district, the Oberon district, Mulbring and the Yengo National Park southwest of Wollombi. These thunderstorms are moving towards the southeast. They are forecast to affect Belmont, Boolaroo and Lake Macquarie by 8:50 pm and Mangrove Mountain, Mangrove Creek Dam and Redhead by 9:20 pm.

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.
* 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.
* Unplug computers and appliances.
* Avoid using the phone during the storm.
* Stay indoors away from windows, and keep children and pets indoors as well.
* For emergency help in floods and storms, ring the SES (NSW and ACT) on 132 500.