Australian Government Bureau of Meteorology New South Wales TOP PRIORITY FOR IMMEDIATE BROADCAST Detailed Severe Thunderstorm Warning for Heavy Rainfall for parts of Sydney and Gosford/Wyong areas. Issued at 4:05 am Wednesday, 18 March 2026. Slow moving thunderstorms are producing heavy rain along the central NSW coast. HEAVY RAINFALL for the following areas: Gosford/Wyong and Sydney A southerly change has been moving up the coast and combining with a mid level trough to trigger heavy rainfall in a moist, unstable atmosphere. Locally intense rainfall has been recorded in northern Sydney but rainfall rates have now eased. The Bureau of Meteorology warns that, at 3:55 am, severe thunderstorms likely to produce heavy rainfall that may lead to flash flooding were detected near Mona Vale, Bundeena and Rooty Hill. These thunderstorms are moving towards the east to northeast. They are forecast to affect Palm Beach, Avalon Beach and waters off Cronulla Beach by 4:25 am and Blacktown, Kurnell and Umina by 4:55 am. 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). A more general severe thunderstorm warning is also current for the Metropolitan and parts of the Hunter and Central Tablelands districts. Other warnings may be current. The next warning is due to be issued by 5:05 am. Check https://www.bom.gov.au/weather-and-climate/warnings-and-alerts. Warnings are also available through TV and Radio broadcasts or call 1300 659 210. The Bureau and State Emergency Service would appreciate warnings being broadcast regularly.