Source: Bureau of Meteorology

For people in Sydney and parts of Blue Mountains/Hawkesbury, Maitland/Cessnock and Gosford/Wyong areas.

Issued at 10:34 pm Tuesday, 18 February 2020.

Weather Situation:

The Bureau of Meteorology warns that, at 10:25 pm, severe thunderstorms were detected on the weather radar near Richmond, Liverpool, Penrith and Colo Heights. These thunderstorms are moving towards the east. They are forecast to affect Parramatta, Sutherland and Sydney Olympic Park by 10:40 pm and Hornsby, Sydney City, Sydney Airport and the Sydney Harbour Bridge by 10:55 pm.

Large hailstones, heavy rainfall that may lead to flash flooding and damaging winds are likely.

49 knot wind gust recorded Nowra Airport at 8:40pm

49.6mm of rain in 60min at Nowra Airport to 9:00pm

27.4mm of rain in 30min at Orange (Agricultural institute) to 8:45pm

Reports of large hail near Mittagong and Wollongong.

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.