Australian Government Bureau of Meteorology New South Wales TOP PRIORITY FOR IMMEDIATE BROADCAST Detailed Severe Thunderstorm Warning for Intense Rainfall, Giant Hailstones And Damaging Winds for parts of Blue Mountains/Hawkesbury, Sydney and Wollondilly/Wingecarribee areas. Issued at 4:18 pm Saturday, 21 March 2026. VERY DANGEROUS THUNDERSTORM OVER PENRITH WITH INTENSE RAINFALL, GIANT HAIL AND DAMAGING WIND GUSTS. INTENSE RAINFALL, GIANT HAILSTONES and DAMAGING WINDS for the following areas: Blue Mountains/Hawkesbury, Sydney and Wollondilly/Wingecarribee The Bureau of Meteorology warns that, at 4:15 pm, a VERY DANGEROUS THUNDERSTORM likely to produce heavy, locally intense rainfall that may lead to dangerous and life-threatening flash flooding, large, possibly giant hailstones and damaging wind gusts was detected near Penrith and Springwood. This thunderstorm is moving towards the northwest. It is forecast to affect Richmond and Windsor by 4:30 pm and Hazelbrook, Kurrajong and the Wollemi National Park north of Kurrajong by 4:45 pm. Other severe thunderstorms likely to produce heavy rainfall that may lead to flash flooding, and possible large hailstones and damaging wind gusts were detected near the area west of Lake Burragorang, the area west of Nattai and the Wollemi National Park southwest of Singleton. These thunderstorms are moving towards the northwest. They are forecast to affect the northwest parts of the Wollondilly Shire by 4:30 pm and the Blue Mountains southwest of Katoomba by 4:45 pm. 4 cm hail was reported at Penrith at 4:00 pm. 91 km/h was recorded at Western Sydney Airport at 3:42 pm. The State Emergency Service advises that people should: * Park your car under secure cover and away from trees, powerlines and drains. * 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. * 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 parts of the Hunter, Metropolitan, Illawarra, Central Tablelands, Southern Tablelands, Central West Slopes and Plains, South West Slopes and Lower Western districts. Other warnings may be current. The next warning is due to be issued by 4:50 pm. 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.