Source: Bureau of Meteorology

For people in parts of Blue Mountains/Hawkesbury and Sydney areas.

Issued at 4:59 pm Thursday, 14 January 2021.

Weather Situation:

The Bureau of Meteorology warns that, at 5:00 pm, severe thunderstorms were detected on the weather radar near Hornsby, Frenchs Forest, Gordon, Terrey Hills and the Glen Davis/Newnes district (north of Lithgow). These thunderstorms are moving towards the east. They are forecast to affect Collaroy, Dee Why, Manly and Mona Vale by 5:15 pm and Colo Heights, the Yengo National Park northwest of St Albans, waters off Manly Beach and waters off Mona Vale Beach by 5:30 pm.

Large hailstones and damaging winds are likely.

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.
* 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.