Source: Bureau of Meteorology

Issued at 3:37 am Wednesday, 18 March 2026.

Slow moving thunderstorms producing heavy, locally intense rain along the central NSW coast.

Weather Situation: A southerly change has been moving up the coast and combining with a mid level trough to trigger heavy and locally intense rainfall in a moist, unstable atmosphere. The heaviest rainfall has been recorded in coastal northern Sydney.

VERY DANGEROUS THUNDERSTORMS are likely to produce heavy, locally intense rainfall that may lead to dangerous and life-threatening flash flooding in the warning area over the next several hours. Locations which may be affected include Gosford, Sydney, Wyong, Penrith, Parramatta and The Entrance.

Severe thunderstorms are no longer occurring in the Illawarra district and the warning for this district is CANCELLED.

93 MM WAS RECORDED AT MOSMAN IN 60 MIN TO 3:03 am

64 mm was recorded at Pearl Beach Reservoir in 60 min to 2:27 am

51 mm was recorded at Allambie in 30 min to 3:04 am

42 mm was recorded at Wahroonga in 30 min to 3:13 am

The State Emergency Service advises that people should:
* 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.
* Stay indoors away from windows, and keep children and pets indoors as well.
For emergency help in flood and storms, ring the SES on 132 500.
Stay updated on the Hazards Near Me NSW app or the ACT ESA website (https://esa.act.gov.au).